Shell and tube heat exchangers are used for the indirect heating or cooling of fluids. As the name implies, a shell and tube heat exchanger consists of two main parts, an outer “shell side” and an inner “tube side,” which sits inside the shell. One fluid flows in the annulus between the inside wall of the shell and the outside wall of the tubes, while the other fluid flows inside the tubes. Heat Transfer within a Shell and Tube Heat Exchanger occurs by heat passing from the cooler fluid to the hotter fluid, through the wall of the tube.

Shell and Tube Heat Exchanger Cross Sectioned

Shell and tube heat exchangers are often described as the "workhorse” of the industrial process industry. The shell and tube heat exchanger is an immensely versatile unit, able to handle a wide range of process applications and conditions. Whether you are looking to cool, heat, vaporise or condense, the shell and tube heat exchanger can meet your needs.

Reasons and conditions under which shell and tube heat exchangers are selected include:

  • High Pressure to Vacuum conditions
      The cylindrical nature of the components that make up a shell and tube heat exchanger provide inherit strength to withstand a full range of pressures from very high to very low (vacuum).
  • High Temperature to Cryogenic cases
      Through material selection and the allowance of differential expansion, shell and tube heat exchangers can be found in applications ranging from stack gas heat recovery through to cryogenic liquefied gases.
  • High Fouling to Ultra Clean Environments
      Provision can be designed into shell and tube heat exchangers to allow them to be quickly cleaned in situ. Selecting the correct design can even allow access to the tubeside without disconnecting pipework. Likewise, shell and tube heat exchangers can be internally polished for applications such as those in Pharma and Bio-pharmaceutical.
  • Heating / Cooling / Condensing / Vaporising
      Whether dealing with single phase fluids, changes in phases or both, you will find shell and tube heat exchangers being used.
  • Large fluctuations in pressure, temperature or external environment
      When considering start-up, shutdown, operating and cyclic natures of processes, a shell and tube heat exchanger often has to deal with much more than the steady state operating conditions. The shell and tube heat exchanger can be designed to handle all of these conditions together with external loads such as wind or shipboard.
  • Wide Range of Materials and Sealing Systems
      The process fluids involved generally dictate the materials that must be used in the design of a shell and tube heat exchanger. As the materials become more exotic and expensive, these materials can be restricted to only the critically important wetted surfaces. For example, in the case of a highly corrosive fluid being cooled by water, it might be possible to limit corrosive fluid to only the tubeside and allow the shell side to be made from a more readily available material. Where the exotic materials are very expensive, it’s often possible to use processes such as weld overlay or explosion bonding to cover a lower value material with a more expensive exotic material, to get the wetted surface protection you require.
  • Most Researched Heat Exchanger
      While shell and tube heat exchangers have been around for a good length of time, our understanding of them and that of fluid flow has not stood still. Both Industry and Research Institutions continue to study the thermal and mechanical designs of shell and tube heat exchangers. Over time, we have seen improvements in the calculation of heat transfer coefficients resulting in smaller units and in turn a better understanding of fluid elastic instability, mitigating the risk of vibration. Our experienced Thermal Design Engineers optimise designs of a shell and tube heat exchangers through considering areas such as process fluids, properties, flowrates, fouling, temperature, pressures, vibration, wind loading, upset, start-up and shutdown conditions, to name but a few.

TEMA is a Standard published by the Tubular Exchanger Manufacturers Association, Inc. (TEMA) for the mechanical design of shell and tube heat exchangers.

The TEMA Standard for shell and tube heat exchangers meet the requirements of most users. Your requirements may exceed the TEMA Standard, but will very rarely be less than. For industrial applications, we would recommend that the TEMA standard be your minimum level of acceptance.

The TEMA Standard is based around the ASME Design Code but is not itself a Design Code. While it is based around ASME, it may be also be used in conjunction with other design codes such as PD5500 or EN13445. Other Standards also exist such as API 660 / ISO 16812 - Petroleum, petrochemical and natural gas industries - Shell-and-tube heat exchangers.

Many users only experience TEMA for the purpose of Nomenclature and describing their requirements. However, TEMA goes much deeper covering areas such as Fabrication Tolerances, Performance Information, Installation, Operation, and Maintenance, Mechanical Standards, Flow Induced Vibration etc.

While almost every shell and tube heat exchanger is different in its design, they do generally have similar geometry characteristics, that allow them to be described through the TEMA three letter system. The table below shows how this lettering system works.

Selection of the configuration can depend on a wide range of factors such as whether the bundle needs to be removed for cleaning, whether the liquids are hazardous or what the pressures and temperatures the unit will see, to name but a few.

Our experienced Thermal Design Engineers will be able to propose an arrangement to meet the your individual requirements.

TEMA A Type Header


TEMA B Type Header


TEMA C Type Header


TEMA N Type Header


TEMA D Type Header


TEMA E Type Center Section


TEMA F Type Center Section


TEMA G Type Center Section


TEMA H Type Center Section


TEMA J Type Center Section


TEMA K Type Center Section


TEMA X Type Center Section


TEMA L Type Header


TEMA M Type Header


TEMA N Type Header


TEMA P Type Header


TEMA S Type Header


TEMA T Type Header


TEMA U Bundle


TEMA W Type Header



Using the above nomenclature, here are some examples...

TEMA BEM Shell and Tube Heat Exchanger

TEMA BEM Shell and Tube Heat Exchanger

TEMA BKU Kettle Shell and Tube Heat Exchanger

TEMA BKU Kettle Shell and Tube Heat Exchanger

The more information that a client can supply, the closer the design can meet the process requirements. The minimum information required, however, is as follows:

  • Fluid Flow Rates
  • Stream Temperatures
  • Stream Composition / Physical Properties Data
  • Stream Pressure
  • Available Pressure Drop

Whether it be NACE spec materials for the Oil Industry or weld overlayed / explosively bonded tubesheets, we manufacture heat exchangers in most combinations of materials.

  • Low-alloy steel
  • Ferritic chromium stainless steels
  • Austenitic chromium-nickel steels
  • Copper-base alloys
  • Nickel-base alloys
  • Titanium
  • Stainless Steel
  • High Nickel Stainless Steel
  • Duplex Stainless Steel
  • Hastelloy
  • Incoloy
  • Cupro Nickel
  • Copper
  • Brass
  • Carbon Steel
  • Low Temperature Steel

With over 50 years of experience in the design and manufacture of shell and tube heat exchangers, Graham Hart (Process Technology) Limited is well known for the production of their TEMA type shell and tube heat exchangers.

Units are exported world-wide and range from 100mm shell diameter up to 50 tonnes, with mechanical design to PD5500, ASME VIII Div I & Div II, BS EN 13445 and Stoomwezen.

But why should you choose Graham Hart (Process Technology) Ltd as your your partner?

  • In-house Thermal, Chemical, Process and Mechanical Engineers, manufacturing and testing.
      Firstly, all of our expertise is in-house, with each discipline having an understanding as to how they interact with the others. A common issue we come across is when the thermal design, mechanical design and fabrication have all be done by independent bodies, either as separate contracts or as sub-contracted services from a single supplier. This often leads to inefficient designs and overlooked issues.
      Everything we do is bespoke to meet our clients individual needs. There is no shoehorning or making do. Our equipment is "Fit for Purpose" meeting our clients individual exacting requirements, resulting in troube free efficient equipment.
  • Code +
      Designing a Shell and Tube Heat Exchanger to design codes and standards is one thing, but it isn't the whole story. With over 50 years of experience we have learnt that to guarantee leak free service, longevity or the ability to handle upset conditions, you cannot rely completely on codes and standards. This is where our Code + comes into play and a philosophy that we employ across all our activities. Many of our clients are not even aware of additional features we have added or actions we have performend to ensure their equipment not only meets their needs, but goes above and beyond.
  • 100% OTIF
      Once an order has been placed, we want to be the partner that you don’t have to worry about. Through regular progress reports and our target of 100% On-Time In-Full, we aim to provide only positive surprises.
  • Plug ‘n’ Play
      We don't employ a specialist servicing and commissioning team, as you don't need one with our equipment. All of our equipment can be installed by your commissioning team and, in most cases, with no additional special tools. We're always happy to provide support where necessary, but in most cases you won't need it.
Header Lifting Lug Header Lifting Lug Tube Side Nozzle Tube Side Nozzle Tube Side Header Tube Side Header Support Feet and Saddle Support Feet and Saddle Baffles Tubes Fixed Tubesheet Nameplate Shell Side Nozzle Shell Side Nozzle Shell Side Nozzle Shell Shell Shell Shell Side Nozzle Header Girth Flange Header Girth Flange Header Girth Flange Header Girth Flange Fixed Tubesheet Tube Side Header Vent Nozzle Tube Side Header Drain Nozzle Tube to Tubesheet joint Tube to Tubesheet joint Fixed Tubesheet Fixed Tubesheet Tubes Header Bolting Header Bolting Header Bolting Header Bolting

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