At the same time, simply designing for the lowest possible pressure drop is not necessarily the answer. Fluid velocity helps drive heat transfer, which means heat exchanger design often involves balancing thermal performance against acceptable pressure loss.

For engineers and industrial buyers, understanding this relationship can make it easier to evaluate a heat exchanger specification and provide the information a manufacturer needs to develop the right design.

What Is Pressure Drop in a Heat Exchanger?

Pressure drop is the reduction in fluid pressure between the inlet and outlet of a heat exchanger.

As fluid moves through tubes, nozzles, fittings, baffles, and other internal flow passages, friction and changes in flow direction consume energy. The result is a lower fluid pressure at the outlet than at the inlet.

Pressure drop is commonly expressed as:

• psi
• kPa
• bar

In a shell and tube heat exchanger, pressure drop must normally be evaluated separately for the shell side and the tube side.

Why Does Heat Exchanger Pressure Drop Matter?

Every process system has limits on how much pressure it can afford to lose while moving fluid through equipment.

If a heat exchanger creates excessive pressure drop, the system may require additional pumping or compression power to maintain the required flow rate. In some cases, excessive resistance can prevent the process from reaching its intended flow rate altogether.

Too much pressure drop can contribute to:

• Reduced process flow
• Higher pump or compressor energy consumption
• Difficulty reaching production targets
• Operating problems elsewhere in the system
• Increased utility costs
• Changes in heat exchanger performance

This is why allowable pressure drop should be established early when getting a heat exchanger for a new process or replacing an existing unit.

What Causes Pressure Drop in a Shell and Tube Heat Exchanger?

Pressure loss comes from several sources throughout the exchanger.

Friction Along the Tubes

As tube-side fluid moves against the interior walls of the tubes, friction creates resistance.

The amount of pressure lost depends on factors such as:

• Tube length
• Tube inside diameter
• Fluid velocity
• Fluid density
• Fluid viscosity
• Surface condition
• Number of tube passes

Longer tubes and higher velocities generally create more resistance to flow.

Inlet and Outlet Nozzles

Pressure can also be lost as fluid enters or exits the exchanger through its nozzles.

Nozzle diameter and velocity must therefore be considered as part of the hydraulic design rather than treating the tube bundle as the only source of resistance.

Tube Passes

Many shell and tube heat exchangers use multiple tube passes. Instead of moving straight through the exchanger once, the fluid changes direction and travels through different sections of the tube bundle.

Increasing the number of passes can increase tube-side velocity, which may improve heat transfer. However, it also increases resistance because the fluid travels farther and changes direction additional times.

Shell-Side Baffles

Baffles direct shell-side fluid across the tube bundle rather than allowing it to travel directly from the inlet to the outlet.

This cross-flow can improve heat transfer by increasing fluid movement across the tube surfaces.

However, every change in direction creates additional resistance.

Baffle spacing, baffle cut, shell diameter, tube layout, and fluid properties can all influence shell-side pressure drop.

The Relationship Between Pressure Drop and Heat Transfer

One of the key challenges in heat exchanger design is that pressure drop and heat transfer performance are closely connected.

Higher fluid velocity can improve heat transfer by increasing turbulence and reducing the thickness of the fluid boundary layer at the heat transfer surface.

But increasing velocity also increases friction.

That creates an engineering tradeoff:

More velocity can improve heat transfer, but it usually increases pressure drop.

The goal is not necessarily to minimize pressure drop. The goal is to achieve the required thermal performance without exceeding the amount of pressure loss the process can tolerate.

Tube Diameter Can Affect Pressure Drop

Tube diameter is one of the variables manufacturers can evaluate when balancing thermal performance and pressure loss.

Smaller flow passages can increase fluid velocity for a given flow rate. That can improve heat transfer, but it may also increase pressure drop.

Larger flow passages may reduce velocity and pressure loss, but reducing velocity too much can decrease heat transfer performance or allow suspended solids to settle in some applications.

The correct tube size therefore depends on more than pressure drop alone.

How the Number of Tube Passes Changes Pressure Drop

The number of tube passes can significantly influence tube-side hydraulics.

Consider a simplified example.

If the entire tube bundle is used for one pass, the total tube-side flow is distributed across a relatively large number of tubes.

If the exchanger is divided into multiple passes, fewer tubes carry the flow during each pass. This increases velocity through those tubes.

Higher velocity may improve thermal performance, but it also creates greater pressure loss.

More passes are not automatically better.

A manufacturer must balance tube velocity, heat transfer requirements, pressure drop, erosion risk, fouling behavior, and mechanical configuration when determining the appropriate pass arrangement.

How Baffle Design Affects Shell-Side Pressure Drop

On the shell side, baffles are used to control how fluid moves around the tube bundle.

Closer baffle spacing generally forces the shell-side fluid to change direction more frequently. This can increase velocity across the tubes and improve heat transfer.

It can also increase pressure drop.

Wider baffle spacing may reduce resistance, but excessive spacing can reduce shell-side velocity and affect heat transfer performance.

Other considerations include:

• Baffle cut
• Baffle type
• Tube spacing
• Tube layout
• Shell diameter
• Bypass flow
• Potential vibration

These factors are evaluated together during thermal design rather than selecting baffle spacing based on a single rule.

Fluid Properties Matter

The same exchanger geometry can produce very different pressure drops depending on the fluid moving through it.

Viscosity

More viscous fluids generally create greater resistance to flow than lower-viscosity fluids.

Viscosity can also change considerably with temperature, so accurate operating temperatures are important when evaluating hydraulic performance.

Density

Fluid density affects velocity and pressure relationships and is another important input in exchanger calculations.

Phase

Gas, liquid, condensing vapor, boiling fluid, and two-phase mixtures behave differently.

Applications involving evaporation or condensation generally require additional analysis because fluid properties and flow conditions can change as the stream travels through the exchanger.

Fouling Can Increase Pressure Drop Over Time

Pressure drop is not only a design consideration. It can also be an important operating indicator.

Scale, sludge, biological material, corrosion products, or process deposits can gradually restrict flow passages inside an exchanger.

As those passages become restricted, resistance increases.

An exchanger that originally operated with an acceptable pressure drop may therefore develop a much higher pressure drop after months or years of service.

A Rising Pressure Drop Can Be a Warning Sign

If operating flow conditions have remained relatively consistent but pressure drop begins increasing, fouling or another internal restriction may be developing.

Operators should evaluate pressure drop alongside other performance indicators such as:

• Inlet and outlet temperatures
• Flow rates
• Heat transfer performance
• Pump operation
• Process throughput

A changing pressure drop is one of several indicators discussed in our guide to early warning signs that a shell and tube heat exchanger needs maintenance.

What Is an Acceptable Pressure Drop?

There is no single acceptable pressure drop that applies to every shell and tube heat exchanger.

The allowable value depends on the surrounding process.

For one application, several psi of pressure loss may be insignificant. In another application, even a relatively small additional pressure loss may interfere with process flow or equipment upstream and downstream.

Important considerations include:

• Available pump head
• Compressor capability
• Required process flow rate
• Upstream pressure
• Required downstream pressure
• Energy consumption
• Control valve requirements
• Pressure available elsewhere in the system

Instead of asking a manufacturer to simply make the pressure drop “as low as possible,” the better approach is to provide the actual maximum allowable pressure loss for each stream.

Shell-Side and Tube-Side Pressure Drop Should Be Specified Separately

The two process streams usually have different hydraulic requirements.

For example, the shell-side process may tolerate a relatively large pressure loss while the tube-side process has very little pressure available.

Your specification should therefore identify:

• Maximum allowable shell-side pressure drop
• Maximum allowable tube-side pressure drop

KAM Thermal’s shell and tube heat exchanger RFQ checklist includes allowable pressure drop among the process information that should be supplied when requesting a quote.

What Happens If the Allowable Pressure Drop Is Set Too Low?

It can be tempting to specify an extremely low allowable pressure drop because less resistance sounds better.

But an unnecessarily restrictive pressure-drop requirement can make the exchanger larger, more complex, or more expensive than the process actually requires.

Reducing pressure drop may require design changes such as:

• Increasing tube diameter
• Increasing the number of tubes
• Reducing tube-side passes
• Increasing shell diameter
• Changing baffle spacing
• Increasing nozzle size
• Changing the overall exchanger configuration

These changes can affect equipment size, thermal performance, materials, fabrication requirements, and cost.

The allowable pressure drop should therefore reflect the real limitations of the process rather than an arbitrary preference for the smallest possible number.

What Happens If the Pressure Drop Is Too High?

When actual pressure drop exceeds the value the process can tolerate, several operating problems may appear.

Reduced Flow

The pump or compressor may not be capable of overcoming the additional resistance while maintaining the required process flow.

Higher Energy Consumption

Additional pumping or compression power may be needed to maintain flow.

Reduced Production

If the required flow rate cannot be maintained, the heat exchanger may become a bottleneck in the process.

Changes in Thermal Performance

Reduced flow can alter exchanger performance, potentially preventing the process from reaching the required outlet temperature.

Maintenance Issues

If rising pressure drop is being caused by fouling or obstruction, continuing to operate without addressing the underlying issue may allow deposits to become more severe.

Pressure Drop in Replacement Heat Exchangers

Pressure drop deserves particular attention when replacing an existing exchanger.

It is not enough to know only the shell diameter, tube length, nozzle sizes, and connection locations of the old equipment.

Whenever possible, gather historical operating information such as:

• Normal inlet and outlet pressures
• Original design pressure drop
• Current operating pressure drop
• Flow rates
• Operating temperatures
• Changes in production capacity
• Fouling history

If an existing exchanger has always created excessive hydraulic resistance, simply duplicating the original design could reproduce the same problem.

A custom replacement provides an opportunity to evaluate whether changes to tube count, passes, nozzles, baffles, shell geometry, or other design variables could better match current process requirements.

Pressure Drop and TEMA Heat Exchanger Design

Shell and tube exchanger specifications commonly use standards developed by the Tubular Exchanger Manufacturers Association.

TEMA provides industry-recognized standards and specification resources used in the design and manufacture of shell and tube heat exchangers.

Additional information is available through the official TEMA standards website.

Information to Give Your Heat Exchanger Manufacturer

Accurate hydraulic design depends on accurate process data.

When requesting a shell and tube heat exchanger, provide information for both streams whenever possible, including:

• Fluid name and composition
• Flow rate
• Inlet temperature
• Required outlet temperature
• Operating pressure
• Design pressure
• Maximum allowable pressure drop
• Density
• Viscosity
• Specific heat
• Thermal conductivity when available
• Fouling characteristics
• Solids or contaminants
• Phase changes

Providing realistic operating data allows the manufacturer to balance thermal duty with the hydraulic limitations of the process.

Pressure Drop Is Part of the Complete Heat Exchanger Design

Pressure drop should never be evaluated in isolation.

It interacts with:

• Heat transfer area
• Fluid velocity
• Tube diameter
• Tube length
• Number of passes
• Tube layout
• Baffle spacing
• Shell diameter
• Nozzle size
• Fouling tendency
• Erosion risk
• Equipment size and cost

A good design balances all of these factors rather than optimizing one at the expense of the rest of the system.

Custom Shell and Tube Heat Exchangers for Industrial Applications

KAM Thermal Equipment is a custom shell and tube manufacturer specializing in heat exchangers for industrial applications.

Our team evaluates thermal duty, flow rates, allowable pressure drop, fluids, materials, operating conditions, maintenance requirements, and mechanical constraints when developing equipment for demanding industrial processes.

As a fourth-generation fabricator of specialized industrial products, KAM Thermal Equipment has been designing and manufacturing heat transfer equipment since 1906.

Need Help Evaluating Your Heat Exchanger Requirements?

If you are designing a new system, replacing an existing exchanger, or dealing with excessive pressure drop in current equipment, KAM Thermal can review your process requirements and help develop the appropriate shell and tube configuration.

Call KAM Thermal Equipment at (631) 348-4880 to discuss your heat exchanger application.

The post Understanding Pressure Drop in Shell and Tube Heat Exchangers appeared first on KAM Thermal Equipment.

There is no single material that is right for every industrial application. A material that performs well with one process fluid may corrode rapidly in another. Temperature, pressure, fluid chemistry, velocity, fouling, cleaning methods, and expected equipment life can all influence the decision.

That is why material selection should be considered early when getting a heat exchanger rather than treated as an afterthought once the thermal design has already been established.

Why Heat Exchanger Material Selection Matters

A shell and tube heat exchanger may operate continuously for years while being exposed to elevated temperatures, pressure, corrosive fluids, contaminants, vibration, and repeated thermal cycling.

The materials of construction must be capable of handling those conditions without introducing an unacceptable risk of corrosion, erosion, cracking, leakage, or premature failure.

Choosing the right materials can help:

• Reduce corrosion and erosion
• Extend equipment service life
• Limit unexpected maintenance
• Reduce the risk of tube leaks and cross-contamination
• Support the required design pressure and temperature
• Improve compatibility with cleaning procedures
• Control initial and long-term equipment costs

The lowest-cost material at the time of purchase is not always the lowest-cost option over the life of the equipment.

What Determines the Best Material for a Heat Exchanger?

Material selection begins with understanding the actual operating environment.

Fluid Chemistry

The fluids flowing through the exchanger are one of the biggest factors in material selection. Acids, salts, chlorides, hydrocarbons, process chemicals, treated water, seawater, steam, and other fluids can interact very differently with different metals.

Engineers should consider the complete chemical composition of each fluid, including contaminants and trace compounds that may affect corrosion.

Operating Temperature

Corrosion behavior can change significantly as temperature increases. A material that performs adequately at moderate temperatures may behave differently at elevated operating temperatures.

Temperature also affects material strength and must be evaluated along with the exchanger’s required design conditions.

Operating and Design Pressure

Materials must provide sufficient mechanical strength for the pressure they will experience.

Higher design pressures can influence wall thickness, tube thickness, flange requirements, tubesheet design, and the materials selected for pressure-retaining components.

Flow Velocity

Fluid velocity matters because excessive velocity can contribute to erosion or erosion-corrosion in certain materials and applications.

Very low velocities can create their own problems by allowing solids to settle or deposits to form.

Fouling and Deposits

A fluid that leaves scale, sludge, biological growth, process residue, or other deposits can create localized corrosion conditions beneath those deposits.

Fouling behavior should therefore be evaluated alongside corrosion resistance rather than as an entirely separate issue.

Cleaning Method

Mechanical cleaning, chemical cleaning, clean-in-place procedures, and high-pressure water cleaning can all affect material selection.

A material should be compatible not only with the process fluid, but also with the chemicals and procedures that will be used to clean the exchanger over its operating life.

Common Heat Exchanger Materials of Construction

Shell and tube heat exchangers can be manufactured from numerous metals and alloys depending on the service. Some of the most commonly considered material families include carbon steel, stainless steels, duplex stainless steels, copper alloys, copper-nickel alloys, and high-nickel alloys.

Carbon Steel Heat Exchangers

Carbon steel is commonly used in industrial equipment because it provides good mechanical strength at a relatively economical cost.

It may be suitable for applications where the process fluids and operating environment are not highly corrosive.

Advantages of Carbon Steel

• Relatively economical compared with many specialty alloys
• Widely available
• Strong and familiar to industrial fabricators
• Suitable for many general industrial applications

Potential Limitations

Carbon steel can be vulnerable to corrosion when exposed to certain water conditions, chemicals, acids, oxygenated environments, or other aggressive fluids.

Corrosion allowance, coatings, water treatment, fluid control, or an alternative alloy may be required depending on the service.

Stainless Steel Heat Exchangers

Stainless steel is commonly considered when greater corrosion resistance is needed than carbon steel can provide.

Different grades of stainless steel have different chemical compositions and corrosion characteristics, so simply specifying “stainless steel” is generally not enough for a detailed industrial heat exchanger specification.

304 Stainless Steel

304 stainless steel is widely used throughout industrial manufacturing and can provide good corrosion resistance in many relatively mild environments.

316 Stainless Steel

316 stainless steel contains molybdenum, which can provide improved resistance to certain forms of corrosion compared with 304 stainless steel.

However, stainless steel should not automatically be assumed to be corrosion-proof. Chloride concentration, temperature, oxygen content, deposits, and other process conditions can significantly affect performance.

Material grade matters.

The correct stainless steel should be selected based on the actual process environment rather than simply choosing stainless because it is perceived as a premium material.

Duplex Stainless Steel

Duplex stainless steels combine characteristics of austenitic and ferritic stainless steels and may be considered for applications requiring increased strength and enhanced resistance to certain corrosion mechanisms.

These alloys can be useful in challenging industrial environments, but their suitability still depends on fluid chemistry, fabrication requirements, operating temperature, and the specific alloy being considered.

Duplex materials can also cost more than conventional stainless steel, so the potential improvement in service life should be weighed against the increased initial investment.

Copper and Copper-Nickel Alloys

Copper-based alloys have a long history in heat transfer equipment because of their favorable thermal conductivity and performance in certain water services.

Copper-nickel alloys may also be considered in marine and other water-handling applications where appropriate.

Where Copper Alloys Can Make Sense

• Water heating and cooling applications
• Marine environments when the specific alloy is suitable
• Applications where strong thermal conductivity is beneficial

Fluid compatibility must still be carefully evaluated because some chemicals and process environments can aggressively attack copper-based materials.

High-Nickel Alloys

High-nickel alloys may be considered for demanding applications involving aggressive chemicals, elevated temperatures, or corrosion environments that conventional steels cannot adequately handle.

These materials can provide excellent performance in the right application, but they also come with significantly higher material and fabrication costs.

For this reason, specialty alloys are often used strategically rather than automatically constructing every component from the same expensive material.

Does the Entire Heat Exchanger Need to Use the Same Material?

No. One of the advantages of a custom shell and tube heat exchanger is that different components can be evaluated individually.

A heat exchanger may include different materials for:

• Shell
• Tubes
• Tubesheets
• Channels or bonnets
• Baffles
• Flanges
• Supports
• Gaskets

For example, an application might allow carbon steel to be used for certain external or shell-side components while requiring a more corrosion-resistant alloy for the tubes that are directly exposed to an aggressive process fluid.

This type of material optimization is one of the advantages of custom shell and tube heat exchanger manufacturing.

Tube Material Is Especially Important

The tubes provide the primary heat transfer surface and are often among the thinnest pressure-containing components in the exchanger.

Even localized corrosion can eventually penetrate a tube wall and create an internal leak between the shell-side and tube-side fluids.

When selecting tube material, engineers may evaluate:

• Corrosion resistance
• Thermal conductivity
• Tube wall thickness
• Fluid velocity
• Operating pressure
• Temperature
• Fouling tendency
• Mechanical cleaning requirements
• Expected service life

Tube material can therefore have a major impact on both initial exchanger cost and long-term reliability.

Tube Sheet Material and Galvanic Compatibility

The tubesheet supports the tube bundle and creates a pressure boundary between the fluids. Because the tubes are mechanically or metallurgically joined to the tubesheet, compatibility between these components deserves particular attention.

Using dissimilar metals in the presence of a conductive fluid can create conditions for galvanic corrosion.

Material selection should therefore consider the complete assembly rather than selecting individual components in isolation.

Cladding and Other Material Strategies

In some applications, clad materials or other engineered material combinations may allow corrosion-resistant material to be concentrated where it is most needed while using a more economical base material elsewhere.

The appropriate approach depends on design requirements, fabrication methods, applicable codes, and process conditions.

Corrosion Should Drive Material Decisions Early

Repeated corrosion problems are often a sign that the operating environment and metallurgy need to be reviewed together.

Simply duplicating the material used in an old exchanger can reproduce the same failure mechanism in the replacement unit.

If an existing exchanger has experienced pitting, tube thinning, repeated leaks, under-deposit corrosion, or other recurring damage, the cause should be investigated before specifying replacement materials.

Our guide to preventing corrosion in shell and tube heat exchangers explains several of the corrosion mechanisms that can affect exchanger service life.

Do More Expensive Materials Always Mean a Better Heat Exchanger?

No.

Using the most expensive alloy available does not automatically create the best design.

A good heat exchanger specification balances:

• Process compatibility
• Mechanical strength
• Corrosion resistance
• Thermal performance
• Fabrication requirements
• Maintenance expectations
• Availability
• Initial cost
• Expected service life

The goal is to select materials that are appropriate for the actual application without adding unnecessary cost or compromising reliability.

Heat Exchanger Materials and ASME Requirements

Material selection for pressure equipment must also account for applicable design and construction requirements.

The ASME Boiler and Pressure Vessel Code includes material specifications and material property information used in the design and fabrication of pressure vessels and related equipment.

ASME Section II covers ferrous materials, nonferrous materials, welding materials, and material properties used throughout the Boiler and Pressure Vessel Code.

More information is available through the official ASME Boiler and Pressure Vessel Code resources.

Information Your Manufacturer Needs Before Selecting Materials

If the correct material has not already been specified, provide your heat exchanger manufacturer with as much operating information as possible.

Important information may include:

• Complete shell-side fluid composition
• Complete tube-side fluid composition
• Contaminants and solids
• Chloride or salt concentrations when applicable
• Operating temperatures
• Design temperatures
• Operating pressure
• Design pressure
• Flow rates
• Expected fluid velocity
• Known corrosion history
• Fouling or scaling concerns
• Cleaning chemicals and procedures
• Previous tube or shell failures
• Required design life

The more information available during the design process, the better the manufacturer can evaluate suitable material options.

Should You Use the Same Material as the Existing Heat Exchanger?

Not necessarily.

If an existing exchanger has provided reliable service for many years under unchanged operating conditions, its original materials can provide useful information for a replacement design.

However, blindly duplicating the old metallurgy is not always the best approach.

Process conditions may have changed. Fluid chemistry may be different. Production rates may have increased. Cleaning chemicals may have changed. A recurring failure may also indicate that the existing material was never ideal for the service.

A replacement project creates an opportunity to evaluate whether material upgrades could improve reliability or equipment life.

Material Selection Is Part of the Complete Heat Exchanger Design

Heat exchanger materials cannot be selected independently from the rest of the equipment.

Material choice interacts with:

• Tube diameter and wall thickness
• Tube layout and pitch
• Shell thickness
• Pressure and temperature ratings
• Thermal expansion
• Tube-to-tubesheet joints
• Welding procedures
• Cleaning access
• Corrosion allowance
• Applicable construction codes

For industrial applications, these factors should be evaluated as one complete system rather than a collection of unrelated specifications.

Custom Heat Exchanger Materials for Industrial Applications

KAM Thermal Equipment is a custom shell and tube manufacturer specializing in heat exchangers for industrial applications.

Our team evaluates process requirements, pressure, temperature, fluids, corrosion concerns, maintenance requirements, and fabrication considerations when developing equipment for demanding operating environments.

As a fourth-generation fabricator of specialized industrial products, KAM Thermal Equipment has been designing and manufacturing heat transfer equipment since 1906.

Need Help Selecting Materials for Your Heat Exchanger?

If you are specifying a new shell and tube heat exchanger or replacing equipment that has experienced corrosion or premature failure, KAM Thermal can review the operating conditions and help evaluate appropriate materials for the application.

Call KAM Thermal Equipment at (631) 348-4880 to discuss your heat exchanger requirements.

The post Heat Exchanger Materials of Construction: How to Choose the Right Material appeared first on KAM Thermal Equipment.

There is no universal rule that says a certain type of fluid must always be placed on the shell side or tube side. Instead, engineers evaluate the operating conditions of both streams and determine the configuration that best fits the application.

Understanding these considerations can also help industrial buyers provide better information when getting a heat exchanger designed for a new or existing process.

What Is the Difference Between the Shell Side and Tube Side?

A shell and tube heat exchanger contains a bundle of tubes enclosed inside a larger pressure vessel called the shell.

Tube Side

The tube side refers to the fluid that flows through the inside of the individual tubes. Depending on the exchanger configuration, the fluid may make one or several passes through the tube bundle before leaving the unit.

Shell Side

The shell side refers to the second fluid, which flows through the space surrounding the outside of the tubes while remaining inside the shell.

Baffles and other internal components can be used to direct shell-side flow across the tube bundle, helping control velocity, heat transfer, vibration, and pressure drop.

How Do Engineers Decide Which Fluid Goes on Which Side?

Fluid allocation is normally based on several operating and mechanical considerations rather than a single rule.

Some of the most important factors include:

• Operating and design pressure
• Corrosion potential
• Fouling and scaling
• Fluid viscosity
• Required flow velocity
• Allowable pressure drop
• Phase change, such as condensation or boiling
• Cleaning requirements
• Materials of construction
• Maintenance access

Several of these factors may point toward different configurations, which is why fluid allocation should be evaluated as part of the complete thermal and mechanical design.

High-Pressure Fluids Are Often Placed on the Tube Side

When one process stream operates at substantially higher pressure than the other, engineers will often consider placing the higher-pressure fluid on the tube side.

The relatively small diameter of individual tubes can make containing high pressure more practical than designing the entire shell for the same pressure.

This can help reduce the amount of heavier or more expensive pressure-retaining material required for the exchanger.

Pressure Is Not the Only Consideration

Although higher-pressure fluids are commonly placed inside the tubes, this is not an automatic rule. Corrosion, fouling, temperature, maintenance requirements, and pressure-drop limits must still be evaluated before determining the final configuration.

Fouling Fluids May Be Better Suited for the Tube Side

Fouling occurs when scale, sediment, biological growth, process material, or other deposits accumulate on heat transfer surfaces.

As deposits build, heat transfer can decrease while pressure drop increases.

When a fluid is expected to foul heavily, placing it inside straight tubes may make maintenance easier because the internal tube surfaces can often be mechanically cleaned.

Cleaning Accessibility Matters

The heat exchanger configuration changes the equation.

Straight tubes are generally easier to access mechanically than U-tubes. Likewise, some shell-side surfaces can be difficult to clean without removing the tube bundle or using chemical cleaning methods.

For that reason, the expected cleaning procedure should be considered during design, rather than after the exchanger has already been installed.

Corrosive Fluids Are Frequently Considered for the Tube Side

Corrosion can significantly affect material selection and the service life of a heat exchanger.

If one fluid requires a corrosion-resistant alloy, placing that fluid on the tube side may reduce the amount of specialized material required. Instead of constructing a large portion of the shell from the more expensive alloy, the design may be able to concentrate corrosion-resistant materials in the tubes, tubesheet, and associated tube-side components.

However, material compatibility must be evaluated for the specific process fluid, concentration, temperature, pressure, and operating environment.

Viscosity Can Influence Shell-Side vs. Tube-Side Selection

Viscous fluids can create another design challenge.

A highly viscous fluid may experience relatively poor heat transfer when flowing through tubes at low velocity. Shell-side flow can sometimes create more mixing as the fluid moves around the tube bundle and through the baffle arrangement.

This can make the shell side attractive for certain viscous services.

But there is a tradeoff. If that same viscous fluid also has a strong tendency to foul or contains suspended solids, cleanability may become more important than the potential heat transfer benefit.

This is where application-specific engineering becomes important.

Pressure, viscosity, fouling, flow rate, thermal performance, and cleaning requirements have to be evaluated together rather than independently.

Allowable Pressure Drop Can Determine Fluid Placement

Every process has a limit on how much pressure can be lost as fluid moves through the heat exchanger.

A greater number of tube passes, smaller flow passages, higher velocities, baffle arrangements, nozzle sizes, and other design variables can all influence pressure drop.

If one process stream has a particularly restrictive allowable pressure drop, the manufacturer may evaluate whether shell-side flow provides greater flexibility for that application.

This is one reason allowable pressure drop should be included when requesting a heat exchanger quote. KAM Thermal’s shell and tube heat exchanger RFQ checklist outlines the process data and operating information that can help manufacturers properly evaluate an application.

What About Condensing or Boiling Fluids?

Phase-changing applications introduce additional considerations.

Vapors that are condensing are commonly evaluated for shell-side service because the shell provides substantial flow area and can accommodate the changing volume associated with condensation.

Boiling applications may also require specialized exchanger configurations designed around vapor generation, disengagement, circulation, and pressure drop.

These applications should not be treated as simple liquid-to-liquid heat transfer problems. The exchanger configuration, orientation, internal components, and fluid allocation all need to work together.

Shell Side vs. Tube Side: General Design Considerations

The following table provides a simplified overview of some common considerations. These are engineering guidelines rather than universal design rules.

No single row in this table should determine the design by itself. The final arrangement depends on the complete operating conditions.

Heat Exchanger Configuration Also Changes the Decision

The physical construction of the exchanger plays an important role in determining where each fluid should flow.

Fixed Tubesheet Heat Exchangers

Fixed tubesheet designs can provide a relatively simple and economical construction, but shell-side mechanical cleaning may be limited because the tube bundle cannot normally be removed from the shell.

That can make shell-side fouling an especially important consideration.

Removable Tube Bundle Designs

A removable bundle can provide greater access to the outside of the tubes and interior of the shell for inspection, cleaning, or repair.

This can make the exchanger more suitable for applications where shell-side maintenance is expected.

U-Tube Heat Exchangers

U-tube configurations allow the tubes to expand and contract as temperatures change, making them useful in applications with significant thermal expansion.

However, the curved portions of the tubes can be more difficult to clean mechanically than straight tubes.

These differences are part of why shell-side and tube-side allocation must be considered alongside the overall exchanger configuration.

TEMA Design Considerations

Shell and tube heat exchanger design is also commonly influenced by standards published by the Tubular Exchanger Manufacturers Association. TEMA standards provide widely recognized guidance related to the mechanical design, fabrication, testing, installation, and maintenance of tubular heat exchangers.

You can learn more through the official TEMA standards information.

KAM Thermal also has a practical guide explaining TEMA standards and exchanger classes for industrial buyers and engineers specifying shell and tube equipment.

There Is No Universal Shell-Side vs. Tube-Side Rule

It is tempting to reduce fluid placement to a short list of rules such as “high pressure goes in the tubes” or “dirty fluid goes in the tubes.”

Those guidelines can be useful starting points, but industrial applications rarely depend on one variable.

For example, one fluid might simultaneously be:

• Highly corrosive
• Very viscous
• Prone to fouling
• Operating at the lower pressure
• Limited to a very small allowable pressure drop

Some of those characteristics may favor tube-side placement while others favor shell-side placement.

The final decision requires balancing thermal performance, mechanical design, maintenance requirements, materials, pressure drop, reliability, and cost.

Information to Provide Your Heat Exchanger Manufacturer

If you are specifying a new shell and tube heat exchanger, provide as much information as possible about both process streams.

Useful information includes:

• Fluid names and chemical composition
• Flow rates
• Inlet temperatures
• Required outlet temperatures
• Operating pressure
• Design pressure and temperature
• Allowable pressure drop
• Density
• Viscosity
• Corrosion concerns
• Solids or contaminants
• Known fouling or scaling conditions
• Cleaning requirements
• Preferred materials of construction
• Space and installation limitations

The manufacturer can use this information to evaluate not only the required heat transfer area, but also which stream should travel through the tubes and which should travel through the shell.

Custom Shell and Tube Heat Exchangers for Industrial Applications

Choosing the shell side and tube side is just one part of designing a reliable heat exchanger. Tube size, tube count, pass arrangement, baffle design, materials, pressure ratings, nozzle configuration, thermal expansion, cleaning access, and applicable construction standards all work together.

KAM Thermal Equipment is a custom shell and tube manufacturer with experience designing and manufacturing heat exchangers for industrial applications. Our team evaluates the actual process conditions behind each application rather than forcing complex operating requirements into a one-size-fits-all configuration.

As a fourth-generation fabricator of specialized industrial products, KAM Thermal provides thermal design, mechanical engineering, manufacturing, replacement equipment, and tube bundle solutions for demanding industrial environments.

Need Help Determining the Right Configuration?

If you are specifying, replacing, or upgrading a shell and tube heat exchanger, KAM Thermal can review your process conditions and help determine the appropriate configuration for your application.

Call KAM Thermal Equipment at (631) 348-4800 to discuss your heat exchanger requirements.

The post Shell Side vs. Tube Side: Which Fluid Goes Where in a Heat Exchanger? appeared first on KAM Thermal Equipment.

The post TEMA Standards Explained: What They Mean for Your Shell & Tube Heat Exchanger appeared first on KAM Thermal Equipment.

Requesting a quote for a shell and tube heat exchanger involves more than providing an equipment size and asking for a price. The manufacturer must understand the thermal duty, operating environment, process fluids, pressure requirements, physical constraints, and applicable construction standards.

A complete request for quotation, commonly called an RFQ, allows the manufacturer to evaluate the application more accurately and reduces the number of follow-up questions required before engineering can begin.

You do not need to have every design decision finalized before contacting a manufacturer. However, gathering the information in this checklist can make the quoting process faster, clearer, and more productive.

Why a Complete Heat Exchanger RFQ Matters

A shell and tube heat exchanger is selected and designed around a specific process. Two units with similar exterior dimensions may have very different tube counts, materials, pressure ratings, pass arrangements, baffle spacing, connection sizes, and thermal capabilities.

An incomplete RFQ can lead to:

• Additional rounds of questions
• Longer quoting timelines
• Incorrect assumptions about operating conditions
• Equipment that does not fit the available space
• Unexpected pressure-drop or performance issues
• Material-selection problems
• Installation changes that were not included in the original project scope

The objective is not simply to quote an exchanger that can transfer heat. It is to identify a configuration that fits the process, facility, maintenance strategy, and long-term reliability requirements.

Shell and Tube Heat Exchanger RFQ Checklist

1. Define What the Heat Exchanger Needs to Accomplish

Begin by explaining the exchanger’s role in the process. Examples include:

• Cooling process oil before it enters downstream equipment
• Heating a viscous product to maintain pumpability
• Condensing process vapor
• Recovering heat from a waste stream
• Maintaining a building or district heating loop
• Cooling equipment or lubricating fluids
• Controlling temperature during chemical production

Include the desired outcome, such as a target outlet temperature, required thermal duty, production rate, or maximum process temperature.

If the exchanger is part of a larger upgrade, explain whether the goal is to increase capacity, reduce energy use, improve temperature stability, eliminate recurring failures, or replace obsolete equipment.

2. Identify the Shell-Side and Tube-Side Fluids

Clearly identify both process streams and indicate which fluid is expected to travel through the tubes and which will travel through the shell.

For each fluid, provide:

• Fluid name and chemical composition
• Concentration
• Specific gravity or density
• Viscosity
• Specific heat
• Thermal conductivity, when available
• Vapor fraction or phase-change information
• Solids content
• Corrosive or erosive properties
• Potential for scaling, coking, crystallization, or biological fouling

A safety data sheet can be helpful, but it may not contain every property needed for thermal design. Provide available process data in addition to the safety documentation.

3. Provide Flow Rates

Flow rate is a central part of heat exchanger selection. Provide the normal flow rate for both streams, along with minimum and maximum rates when the process varies.

Clearly label the units, such as:

• Gallons per minute
• Pounds per hour
• Cubic feet per minute
• Kilograms per hour

Variable flow can affect heat-transfer performance, fluid velocity, pressure drop, fouling behavior, and control-system operation. If the process runs in batches or experiences seasonal demand changes, describe those operating patterns in the RFQ.

4. List Inlet and Outlet Temperatures

For each fluid stream, provide:

• Inlet temperature
• Required or expected outlet temperature
• Minimum operating temperature
• Maximum operating temperature
• Startup or cleaning temperature, when applicable

If one outlet temperature is unknown, state which process target must be achieved. The manufacturer may be able to calculate the expected outlet condition when the flow rates, fluid properties, and other temperatures are known.

5. Separate Operating Conditions From Design Conditions

Operating pressure and temperature describe the conditions normally experienced during production. Design pressure and design temperature define the mechanical limits used to engineer the equipment.

These values are not necessarily the same.

The RFQ should clearly distinguish:

• Shell-side operating pressure
• Tube-side operating pressure
• Shell-side design pressure
• Tube-side design pressure
• Shell-side design temperature
• Tube-side design temperature
• Vacuum conditions, when applicable
• Pressure-relief or upset conditions

Also identify whether one side can remain pressurized while the other side is empty. Differential-pressure scenarios can influence mechanical design.

6. State the Maximum Allowable Pressure Drop

Pressure drop is the reduction in fluid pressure as the stream moves through the exchanger. A design that transfers heat effectively may still create operating problems if the pressure loss exceeds what the pump, compressor, or process can tolerate.

Provide the maximum allowable pressure drop for both the shell side and tube side. This information helps the manufacturer evaluate:

• Tube diameter and quantity
• Number of tube passes
• Baffle spacing
• Fluid velocity
• Nozzle size
• Potential fouling and erosion concerns

If allowable pressure drop is unknown, provide available pump or system information so the issue can be discussed during application review.

7. Describe Corrosion, Fouling, and Cleaning Requirements

Real-world process conditions matter as much as theoretical thermal performance. Tell the manufacturer about known operating challenges, including:

• Mineral scaling
• Sludge or sediment
• High-viscosity products
• Fibers or suspended solids
• Corrosive chemicals
• Chlorides
• Tube erosion
• Product buildup
• Biological fouling
• Coking or polymerization

Explain how the exchanger will be cleaned and how frequently cleaning is expected. Mechanical cleaning, chemical cleaning, clean-in-place procedures, and bundle removal can each affect the most appropriate exchanger configuration.

8. Identify Material Requirements

If material requirements have already been established, list them for each major component. These may include:

• Shell
• Tubes
• Tubesheets
• Channels or bonnets
• Baffles
• Flanges
• Gaskets
• Supports

If materials have not been selected, provide detailed fluid and operating information. The manufacturer can then review possible materials based on corrosion risk, pressure, temperature, fabrication requirements, service life, and project budget.

Do not select material solely because it was used in the existing exchanger. Repeated tube failures or corrosion may indicate that the original material is no longer appropriate for the application.

9. Document Space and Installation Constraints

A technically effective exchanger still needs to fit through the building, onto its supports, and between the existing piping connections.

Include:

• Maximum overall dimensions
• Horizontal or vertical orientation
• Foundation and support details
• Existing bolt patterns
• Nozzle centerline dimensions
• Piping loads, when known
• Door, roof, crane, or rigging restrictions
• Available space for removing covers
• Available space for pulling the tube bundle

Photographs and marked-up layout drawings can communicate these constraints more clearly than a written description alone.

10. Specify Applicable Codes and Documentation

Identify any required codes, standards, customer specifications, or documentation packages. Depending on the application, requirements may include:

• ASME Section VIII, Division 1
• TEMA requirements
• Customer-specific engineering standards
• Welding and inspection requirements
• Nondestructive examination
• Pressure testing
• Material traceability
• Certified drawings
• Data reports
• Quality-control documentation

KAM Thermal manufactures shell and tube heat exchangers for applications requiring ASME Section VIII, Division 1 construction and TEMA-compliant design.

Information Needed for a Replacement Heat Exchanger Quote

When replacing an existing unit, include the process information above along with documentation of the current exchanger.

Helpful replacement information includes:

• Original drawings and data sheets
• Nameplate photographs
• Manufacturer, model, and serial number
• Overall equipment photographs
• Shell diameter and overall length
• Support and mounting dimensions
• Nozzle sizes, ratings, and locations
• Tube size, tube count, and tube length, when known
• Materials of construction
• Inspection and maintenance history
• A description of the reason for replacement

If original drawings are unavailable, review our guide to replacing an obsolete heat exchanger without drawings.

What If Some Heat Exchanger Specifications Are Unknown?

Do not delay contacting a manufacturer simply because every field on a data sheet is not complete. Some customers have a detailed engineering specification. Others have an equipment nameplate, a few photographs, and a process problem that needs to be solved.

At minimum, try to provide:

• The purpose of the exchanger
• The two process fluids
• Available flow rates
• Available inlet and outlet temperatures
• Operating pressures
• Known physical limitations
• Whether the project is new equipment or a replacement

Clearly label estimated, assumed, and unknown values. An honest blank space is more useful than a confident-looking number that does not reflect the process.

Common RFQ Mistakes That Delay a Quote

Several common issues can slow the evaluation process:

• Providing temperatures without identifying which fluid they belong to
• Listing flow rates without units
• Confusing operating pressure with design pressure
• Leaving out allowable pressure drop
• Using general fluid descriptions such as “oil” or “process water” without additional detail
• Failing to disclose solids, viscosity, corrosion, or fouling concerns
• Providing overall dimensions without nozzle locations
• Requesting an exact duplicate without explaining why the original unit failed
• Leaving code and documentation requirements until after the quote
• Waiting until a shutdown is imminent before beginning the replacement process

A brief explanation of the process and its challenges can be just as valuable as the numbers on the RFQ.

What Happens After You Submit a Heat Exchanger RFQ?

After receiving the application information, the manufacturer may:

1. Review the process duty and available data.
2. Identify missing or conflicting information.
3. Confirm thermal and mechanical requirements.
4. Discuss standard versus custom configuration options.
5. Review materials and code requirements.
6. Evaluate dimensional and installation restrictions.
7. Prepare a proposal based on the defined project scope.

Complex or unusual applications may require additional discussion before a reliable proposal can be developed. Involving the manufacturer early can help uncover issues before piping, foundations, schedules, or equipment layouts become fixed.

Request a Custom Shell and Tube Heat Exchanger Quote

KAM Thermal Equipment provides thermal design, mechanical engineering, and manufacturing for custom and standard shell and tube heat exchangers. Since 1906, our team has supported industrial and commercial applications across industries including manufacturing, asphalt production, oil and gas, chemical processing, and power generation.

Submit your heat exchanger application or call (631) 348-4800 to discuss your operating requirements with KAM Thermal Equipment.

Frequently Asked Questions

What is the minimum information needed for a heat exchanger quote?

At minimum, provide the two process fluids, available flow rates, inlet and outlet temperatures, operating pressures, the purpose of the exchanger, and any known dimensional restrictions. Additional information may be required before a final configuration can be developed.

Can I request a replacement quote using only the existing nameplate?

A nameplate is a useful starting point, but it may not contain enough information to confirm current thermal performance or physical configuration. Include photographs, dimensions, operating conditions, nozzle information, and available drawings whenever possible.

Do I need to select the heat exchanger materials before requesting a quote?

Not necessarily. If materials have not been selected, provide detailed information about the fluids, concentrations, temperatures, pressures, corrosion concerns, and expected service conditions so suitable options can be evaluated.

Can KAM Thermal duplicate a heat exchanger made by another manufacturer?

KAM Thermal can evaluate replacement shell and tube heat exchangers and tube bundles originally manufactured by other companies. Available drawings, nameplate information, measurements, photographs, and operating data help determine the appropriate replacement approach.

Should an RFQ include both operating pressure and design pressure?

Yes. Operating pressure describes normal process conditions, while design pressure is used to establish the mechanical pressure rating of the equipment. Both shell-side and tube-side values should be clearly identified.

The post Shell & Tube Heat Exchanger RFQ Checklist appeared first on KAM Thermal Equipment.

Replacing an aging industrial heat exchanger is challenging enough when the original drawings and specifications are available. When those records have disappeared, the original manufacturer is no longer operating, or the equipment has been modified over several decades, the process can feel considerably more complicated.

Fortunately, missing drawings do not automatically make replacement impossible.

An experienced shell and tube heat exchanger manufacturer can often evaluate the existing equipment, document its physical configuration, review current operating conditions, and engineer a replacement that fits the application.

The key is gathering the right information before the existing unit reaches the end of its usable life.

Can an Obsolete Heat Exchanger Be Replaced Without Original Drawings?

In many cases, yes. A replacement shell and tube heat exchanger may be designed using a combination of:

• Equipment nameplate information
• Physical measurements
• Photographs of the existing unit
• Nozzle locations and connection sizes
• Current operating temperatures and pressures
• Process-fluid information
• Available maintenance and inspection records
• Information from the facility’s piping and instrumentation diagrams

The replacement does not always need to be an exact copy of the original design. In some situations, duplicating the existing dimensions and connections is the best way to simplify installation. In others, the replacement presents an opportunity to correct recurring problems, improve material selection, or adapt the exchanger to operating conditions that have changed since the original unit was installed.

Why Original Heat Exchanger Records Go Missing

Industrial shell and tube heat exchangers can remain in service for many years. During that time, facilities change ownership, engineering records move between departments, equipment manufacturers close, and process conditions evolve.

Common reasons documentation may be incomplete include:

• The exchanger predates the facility’s current document-management system.
• The original manufacturer is no longer in business.
• The exchanger was installed as part of a larger packaged system.
• Previous modifications were not added to the original drawings.
• The nameplate is damaged, painted over, corroded, or unreadable.
• The facility inherited the equipment through an acquisition or property purchase.
• Only partial maintenance records remain.

This is especially common in older manufacturing plants, refineries, utility facilities, commercial HVAC systems, asphalt operations, and other facilities where equipment may remain in service through several generations of plant personnel.

Information to Gather Before Requesting a Replacement

The more information a manufacturer receives at the beginning of the project, the easier it is to evaluate the existing exchanger and identify any missing pieces.

1. Photograph the Equipment Nameplate

Start with clear, close-up photographs of the equipment nameplate. Even a partially readable plate may contain valuable information such as:

• Original manufacturer
• Model or serial number
• Year of manufacture
• Shell-side and tube-side design pressure
• Design temperature
• Heat-transfer surface area
• Materials of construction
• National Board number
• ASME code information

Do not remove or discard a damaged nameplate before documenting it. Photograph it from several angles and under different lighting conditions. Small details that appear unreadable in person may become clearer when the image is enlarged.

2. Take Overall and Detailed Photographs

Photographs help document the exchanger’s configuration and its relationship to surrounding equipment. Capture:

• The complete exchanger from multiple sides
• Front and rear heads or channels
• Shell-side and tube-side nozzles
• Supports, saddles, legs, or mounting brackets
• Expansion joints, vents, drains, and instrumentation connections
• Adjacent piping and structural obstructions
• Available clearance for maintenance or bundle removal

Include a known reference dimension in the photographs when possible. A tape measure placed beside a nozzle or flange can provide helpful scale.

3. Record the Exchanger’s Physical Dimensions

A replacement unit must fit the available space and connect properly to the existing system. Important measurements may include:

• Overall length, width, and height
• Shell diameter
• Distance between supports
• Support height and bolt-hole pattern
• Nozzle diameter and flange rating
• Nozzle orientation
• Distance between nozzle centerlines
• Channel and bonnet dimensions
• Maintenance and bundle-pulling clearance

Measurements should be verified rather than estimated whenever possible. A small dimensional discrepancy can create significant installation problems when connecting to existing piping or foundations.

4. Identify the Process Fluids

The manufacturer needs to know what flows through the shell side and what flows through the tube side. Provide the exact fluid or mixture whenever possible, along with any available information about:

• Chemical composition
• Concentration
• Viscosity
• Specific gravity
• Solids or suspended particles
• Corrosive characteristics
• Potential for scaling or fouling
• Contamination restrictions

Fluid characteristics influence material selection, tube velocity, fouling allowances, cleaning access, and other design decisions.

5. Document Current Operating Conditions

Do not rely exclusively on the original operating conditions, especially if the process has changed over time. Record the conditions the exchanger currently experiences, including:

• Normal operating pressure
• Maximum expected operating pressure
• Shell-side inlet and outlet temperatures
• Tube-side inlet and outlet temperatures
• Flow rates
• Allowable pressure drop
• Startup and shutdown conditions
• Frequency and severity of thermal cycling

The replacement should be designed around the actual application, not an outdated assumption about how the process operates.

6. Gather Performance and Maintenance History

Maintenance records can reveal whether the existing exchanger’s problems are caused by normal age or by a design that no longer matches the process.

Useful records include:

• Inspection reports
• Pressure-test results
• Tube-plugging history
• Cleaning frequency
• Corrosion or erosion findings
• Leak history
• Temperature and pressure trends
• Production losses associated with the exchanger

If the unit has experienced repeated tube failures, excessive fouling, vibration, thermal fatigue, or an inability to reach target temperatures, simply copying the old design may reproduce the same problem.

Should the New Heat Exchanger Be Duplicated or Redesigned?

There are two general approaches to replacing obsolete equipment: duplicating the existing exchanger or engineering an updated replacement.

When Duplication May Make Sense

A close dimensional replacement may be appropriate when:

• The existing exchanger performed reliably for most of its service life.
• Process conditions have not materially changed.
• The available footprint is highly restricted.
• Existing piping connections cannot be moved easily.
• Minimizing installation work is a primary objective.
• The original materials remain appropriate for the application.

KAM Thermal maintains a database that may help cross-reference and duplicate tube bundles originally fabricated by other manufacturers. This can be particularly useful when the original manufacturer is unavailable or the existing model has been discontinued.

When Redesigning May Be the Better Choice

An updated design may be beneficial when:

• Production rates have increased.
• Process fluids or concentrations have changed.
• The unit experiences repeated corrosion or tube failures.
• Current performance does not meet outlet-temperature requirements.
• Pressure drop is restricting system performance.
• Cleaning and inspection access is inadequate.
• The exchanger has become a production bottleneck.
• Different materials may provide better service life.

Rather than treating the project as a simple equipment swap, the manufacturer can compare the existing geometry with the present thermal and mechanical requirements.

Tube Bundle Replacement or Complete Heat Exchanger Replacement?

Not every aging exchanger requires complete replacement. Depending on the design and the condition of the pressure-containing components, replacing the tube bundle may be an option.

A replacement tube bundle may be evaluated when:

• The shell remains structurally sound.
• The channels, bonnets, and covers remain serviceable.
• Damage is concentrated in the tubes or tubesheets.
• The existing exchanger was designed with a removable bundle.
• The current shell and nozzle arrangement still meets process requirements.

A complete replacement may be more appropriate when:

• The shell or other pressure-containing components are compromised.
• Corrosion is widespread throughout the unit.
• The original design no longer provides adequate thermal performance.
• Existing materials are incompatible with the process.
• Several major components are approaching the end of their service life.
• The exchanger cannot be modified safely or economically for new operating conditions.

For additional information about removable bundles, visit KAM Thermal’s tube bundle removal and replacement guide.

How a Custom Replacement Heat Exchanger Is Developed

Although every project is different, developing a replacement generally involves several important stages.

1. Document the existing equipment. Available drawings, nameplate data, photographs, measurements, and maintenance records are collected.
2. Confirm current process requirements. Operating conditions, fluids, flow rates, temperature targets, pressure limitations, and performance concerns are reviewed.
3. Evaluate the existing configuration. The manufacturer determines which dimensions and connections must remain fixed and which design elements may be improved.
4. Complete thermal and mechanical design. The replacement is engineered to provide the necessary heat-transfer performance while meeting mechanical and code requirements.
5. Verify materials and fabrication requirements. Materials, welding procedures, testing, inspection, and documentation requirements are established.
6. Fabricate and test the equipment. The exchanger is manufactured and inspected before shipment.

KAM Thermal manufactures custom and standard shell and tube heat exchangers in the United States for demanding industrial and commercial applications.

How to Reduce Downtime During an Obsolete Equipment Replacement

The best time to begin planning a replacement is before the existing exchanger fails completely. Early planning gives the facility and manufacturer more time to verify information, resolve missing data, and coordinate fabrication with a planned shutdown.

To reduce replacement-related downtime:

• Begin documenting aging equipment during routine inspections.
• Photograph every nameplate before it becomes unreadable.
• Digitize old drawings and inspection records.
• Track changes in flow, temperature, pressure, and production demand.
• Identify piping, structural, and rigging restrictions early.
• Confirm how the existing unit will be removed.
• Verify maintenance clearance for the replacement.
• Coordinate delivery with the planned outage schedule.

Waiting until a unit suffers a critical failure can turn a manageable equipment project into an emergency procurement situation.

Replace Obsolete Heat Exchanger Equipment With Confidence

Missing drawings do not need to bring a replacement project to a standstill. Physical dimensions, operating data, photographs, maintenance history, and application knowledge can provide the foundation for a properly engineered replacement.

Since 1906, KAM Thermal Equipment has provided thermal and mechanical design, engineering, and manufacturing for industrial and commercial applications. Our team manufactures custom shell and tube heat exchangers and replacement tube bundles designed around each customer’s operating requirements and physical constraints.

Contact KAM Thermal Equipment or call (631) 348-4800 to discuss an obsolete heat exchanger, discontinued model, or replacement project.

Frequently Asked Questions

Can an old heat exchanger be replaced if the manufacturer is no longer in business?

Often, yes. An experienced manufacturer may be able to develop a replacement using nameplate information, photographs, physical measurements, current operating conditions, and available maintenance records.

Can a replacement be made if the heat exchanger nameplate is unreadable?

An unreadable nameplate makes the project more complex, but it does not necessarily prevent replacement. Physical measurements, piping information, operating data, photographs, inspection records, and other facility documentation may help establish the necessary requirements.

Does a replacement heat exchanger need to be identical to the original?

Not always. Critical dimensions and connection locations may need to match the existing system, but materials, internal geometry, tube configuration, and other design details may be updated when current operating conditions justify a change.

Can only the tube bundle be replaced?

A replacement tube bundle may be considered when the exchanger has a removable bundle and the shell and other pressure-containing components remain suitable for continued service. The condition and design of the complete exchanger must be evaluated before determining the appropriate replacement approach.

What should be sent to KAM Thermal to begin a replacement quote?

Provide any available drawings, nameplate photographs, overall equipment photographs, physical dimensions, nozzle information, process-fluid details, operating temperatures, pressures, flow rates, and a description of current performance problems.

The post Replacing an Obsolete Heat Exchanger Without Drawings appeared first on KAM Thermal Equipment.

The post How to Choose the Right Heat Exchanger Manufacturer appeared first on KAM Thermal Equipment.

The post Getting a Heat Exchanger appeared first on KAM Thermal Equipment.

Routine inspections are essential to maintaining the performance, safety, and longevity of shell & tube heat exchangers. These inspections help identify early wear, fouling, corrosion, and mechanical stress long before they turn into leaks or unplanned shutdowns. For facilities that depend on reliable heat transfer, consistent inspection practices are one of the most cost-effective reliability strategies.

This guide outlines what operators should look for during inspections and how early detection helps prevent larger issues down the line.

Why Routine Inspections Matter

Shell & tube heat exchangers often run for years under demanding conditions. While built to last, gradual deterioration is inevitable. Inspections allow operators to spot:

• Minor leaks forming at tube joints or gaskets
• Scaling or fouling that reduces thermal efficiency
• Corrosion that weakens tubes or tube sheets
• Vibration or mechanical stress in baffles or tie rods

If you’re trying to identify issues even earlier, review
5 Early Warning Signs Your Heat Exchanger Needs Maintenance.

Key Areas to Examine During an Inspection

A thorough inspection includes both external and internal review. Key areas include:

• Tube surfaces: Look for pitting, deposits, erosion, or discoloration.
• Tube-to-tube-sheet joints: Inspect for seepage, cracking, or movement.
• Gaskets & flanges: Check compression, alignment, and gasket integrity.
• Shell exterior: Look for rust streaks, leaks, or insulation damage.
• Vents & drains: Confirm they are clear and operating properly.

If corrosion is a recurring issue, see
How to Prevent Corrosion in Heat Exchangers.

Watching Performance Indicators

Often, performance changes provide the earliest signs of internal problems. During routine inspections, operators should review:

• Inlet and outlet temperature changes
• Pressure drop across the exchanger
• Flow rate variations
• Unexpected contamination between fluids

If contamination is suspected, check out
How to Troubleshoot Heat Exchanger Leaks.

Inspecting for Fouling or Blockage

Fouling is one of the most common issues found during inspections. Even a thin layer of deposit can reduce efficiency significantly.

Inspection should look for:

• Scale buildup from minerals
• Sludge, mud, or sediment accumulation
• Biological fouling from untreated fluids
• Flow restrictions or blocked tube passages

If cleaning is required, compare cleaning options in
Mechanical vs. Chemical Cleaning Methods.

Thermal & Mechanical Stress Indicators

Stress from rapid temperature changes or vibration can weaken a heat exchanger over time. Inspections should check for:

• Cracked gaskets from thermal cycling
• Misalignment of tube sheets
• Vibration marks on baffles
• Distortion near welds or supports

To reduce stress-related damage, review
How to Prevent Thermal Shock in Heat Exchangers.

Inspection Frequency Recommendations

The ideal inspection frequency depends on application, fluid quality, operating temperature, and fouling tendency. As a general guideline:

• High-fouling applications: Inspect quarterly
• Standard industrial applications: Inspect every 6–12 months
• Critical process systems: Inspect during every planned shutdown

Documenting each inspection helps track wear patterns and predict when cleaning or bundle replacement will be required.

When Replacement Becomes Necessary

Sometimes inspections reveal damage that cleaning or minor repairs cannot solve. Severe tube thinning, widespread corrosion, or repeated leaks may indicate the need for a replacement tube bundle.

KAM Thermal Equipment manufactures:

• Custom replacement tube bundles
• Replicas for OEM and discontinued models
• Upgraded materials for corrosion and erosion resistance

To learn how the replacement process works, see
Tube Bundle Removal & Replacement Guide.

Additional Resources

• Preventative Maintenance Strategies
• Straight Tube vs. U-Tube Cleaning Requirements
• Benefits of Custom Heat Exchanger Manufacturing

Need a Replacement Tube Bundle?

KAM Thermal Equipment engineers and manufactures high-performance replacement tube bundles designed to extend the life and reliability of your heat exchanger. If inspections reveal tube degradation or early failure, our team can design a precise, application-matched solution.

Contact KAM Thermal Equipment →

The post Routine Inspections for Shell & Tube Heat Exchangers appeared first on KAM Thermal Equipment.

Industrial processes rely on heat exchangers that are reliable, efficient, and built to withstand demanding operating conditions. While standard, off-the-shelf shell & tube exchangers work for some applications, many facilities require custom designs tailored to specific temperatures, pressures, flow rates, and materials. Custom manufacturing ensures the exchanger matches real-world conditions rather than forcing the process to adapt to a generic design.

This guide explains the key benefits of custom shell & tube heat exchanger manufacturing and why many operators choose engineered solutions over standardized units.

Designed for Your Exact Operating Conditions

Every industrial process has unique parameters. Custom heat exchangers allow engineers to optimize thermal performance by matching design factors such as:

• Temperature and pressure requirements
• Fluid compatibility and chemical resistance
• Targeted heat transfer capacity
• Flow characteristics and velocity control
• Space constraints or layout limitations

Custom design eliminates inefficiencies seen in “one-size-fits-all” equipment and can improve overall process stability.

Enhanced Material Selection for Corrosion and Wear Resistance

Materials play a major role in extending service life. Custom manufacturing lets operators choose the right combination of tube, shell, and tube sheet materials based on process chemistry, operating temperature, and fouling tendencies.

Common upgrade options include:

• Stainless steels and duplex alloys
• Copper and copper-nickel alloys
• High-nickel alloys for aggressive or corrosive environments
• Coated or clad components for added protection

For corrosion-specific strategies, explore
How to Prevent Corrosion in Heat Exchangers.

Optimized Tube Layouts and Bundle Designs

Tube count, pitch, diameter, and layout significantly impact heat exchanger performance. Custom engineering ensures the bundle is optimized for:

• Maximum heat transfer efficiency
• Balanced flow distribution
• Reduced fouling or scaling potential
• Improved cleanability and maintenance access
• Specific thermal duties or pressure drops

When tube bundles eventually require replacement, operators can also choose performance upgrades. Learn more here:
Tube Bundle Removal & Replacement Guide.

Better Long-Term Performance and Cost Efficiency

While custom heat exchangers may have a higher upfront cost than standard models, they typically reduce total lifecycle expenses by:

• Improving heat transfer efficiency
• Reducing downtime caused by premature failure
• Minimizing the need for frequent cleaning
• Lowering energy consumption and operating costs
• Extending equipment lifespan through material and design optimization

Many operators find that custom engineering pays for itself through reliability and lower maintenance costs alone.

Flexibility for Replacement, Upgrades, and Retrofitting

Custom manufacturing is especially valuable when replacing aging, discontinued, or proprietary OEM units. KAM Thermal Equipment builds:

• Exact-fit replicas of obsolete or legacy equipment
• Upgraded designs to improve corrosion and fouling resistance
• Enhanced-performance bundles for increased throughput
• Units compatible with existing piping and mounting constraints

This flexibility makes custom fabrication ideal for facilities modernizing older systems or adapting to updated process demands.

Precision Engineering for Critical Applications

High-demand industries such as petrochemical, power generation, offshore operations, and pharmaceuticals often require tighter tolerances and specialized designs. Custom heat exchangers provide:

• Verified mechanical integrity under extreme conditions
• Precise thermal calculations based on real process data
• Compliance with ASME and TEMA standards
• Material traceability and rigorous quality control

For operators working in corrosion-heavy or thermally volatile environments, custom engineering is more than a benefit — it’s a necessity.

Additional Resources

• Preventative Maintenance Strategies
• Cleaning Options for Heat Exchangers
• Preventing Thermal Shock in Heat Exchangers

Need a Custom-Engineered Shell & Tube Heat Exchanger?

KAM Thermal Equipment specializes in designing and manufacturing custom shell & tube heat exchangers and replacement tube bundles built for demanding industrial applications. Whether you need a performance upgrade, materials engineered for corrosion resistance, or a replica of an older unit, our team delivers reliable, application-matched solutions.

Contact KAM Thermal Equipment →

The post Benefits of Custom Shell & Tube Heat Exchanger Manufacturing appeared first on KAM Thermal Equipment.