Heat Exchanger Datasheet Explained Line by Line (TEMA)

A TEMA heat exchanger datasheet, which TEMA calls the Heat Exchanger Specification Sheet, is the two page form that defines a shell and tube exchanger for quotation. The buyer fills in the duty: which fluid goes where, flows, temperatures, properties, allowable pressure drops, fouling resistances, design conditions, materials and TEMA class. The thermal designer, usually the fabricator, returns the size and type, surface area, coefficients, calculated pressure drops, tube and baffle details and weights.

Read it as a conversation in two halves. Your half has to be complete and consistent, or every bidder will design something different.

Why this matters now

TEMA, the Tubular Exchanger Manufacturers Association, issued the 2026 edition of its standards on 1 August 2026 [1, 2]. TEMA says the specification sheet has been revised to define the design requirements more fully [1]. The sheet is a free download in US customary and SI units, as PDF and Excel [2].

The recent revision of the sheet added a table for several design and operating conditions, which the designer needs to decide whether an expansion joint is required, a second page for an outline sketch, and fuller configuration and materials sections [3]. If your project template still carries an old one page form, those lines are missing.

The top block: service, size and type

The header names the job, item number and service of unit, a short description such as "product cooler" [4]. Next come size, horizontal or vertical, whether shells are connected in parallel or series, and the TEMA type. The type is three letters for the front head, shell and rear head: a BEM has a B front head, an E shell and an M rear head [5]. Our guide to TEMA heat exchanger types explains each letter. Size, surface per unit and shells per unit are normally the designer's answer, not yours [4].

Performance of one unit: the lines you must fill

This block carries the duty for each side, inlet and outlet [4].

• Fluid allocation. Which fluid goes in the shell and which in the tubes. A common rule is to put the dirtier, more corrosive or higher pressure fluid in the tubes, which are easier to clean and cheaper to make from alloy. If you have no view, say so and let the designer choose.
• Fluid quantity and phase. Total flow, split into vapour, liquid, non condensables, steam or water at inlet and outlet. This tells the designer whether there is condensing or boiling.
• Temperatures in and out on both sides.
• Properties: density, viscosity, specific heat, thermal conductivity and latent heat at inlet and outlet. Values at one temperature only are a frequent cause of poor designs in viscous service.
• Inlet pressure, in absolute units on the SI sheet.
• Pressure drop, allowable. Your limit for each side. The designer fills in the calculated value beside it.
• Fouling resistance. The allowance for dirt building up on each surface. Choose it carefully, because generous fouling factors oversize the exchanger [6].

The designer then returns velocity, film coefficients, heat exchanged, mean temperature difference (MTD) and the required transfer rate [4].

Construction of one shell, and page two

Here you give design pressure (internal and external), design temperature, MDMT (minimum design metal temperature, the coldest the metal may see), and corrosion allowance, the extra wall thickness that may be lost over the exchanger's life [4]. Nozzle sizes and ratings, tube count, diameter, length and pitch, baffle type and spacing, supports, impingement protection and weights are mostly the designer's answers, though you can fix any of them if your site standards require it.

Page two holds the design code, whether a code stamp is required, the TEMA class, customer inspection, cyclic service, the materials list and the table of design, operating and upset conditions [4]. TEMA class R is the most demanding and is used in refineries; class C is the least demanding, for general service; class B is for chemical service and is close to R without some of its extra requirements [5].

Template: who gives each line

Practical example

In this illustrative example, a product cooler takes 20,000 kg/h of liquid with a specific heat of 2.2 kJ/kg K from 90 °C to 40 °C. The duty is 20,000 ÷ 3,600 × 2.2 × 50, which is about 611 kW.

The draft datasheet shows cooling water at 50,000 kg/h from 28 °C to 38 °C. That side carries only 50,000 ÷ 3,600 × 4.18 × 10, about 581 kW, so the heat balance is out by 5%. To close it, the water flow must be about 52,600 kg/h. Fix this before the RFQ, or each bidder will choose its own answer.

With counterflow temperature differences of 52 K and 12 K, the log mean temperature difference is about 27.3 K. If a designer's service coefficient were 500 W/m² K and the MTD correction factor 0.85, the surface would be about 53 m². Now suppose process adds 10% to the duty and the designer adds 20% to the area: the exchanger grows to about 70 m², 32% larger. Chemical Processing describes a case where two 25% margins left an exchanger 56% oversized, so velocity fell and it fouled fast [7]. State margin once, on one line, and say where it applies.

Where ChemCapital fits

ChemCapital lets you send one structured RFQ with line items and attachments, such as the TEMA sheet and your materials specification, to several fabricators at once, and quotes come back in a consistent format. Incoming quotes are checked for missing fields, unit mismatches and scope differences before you compare prices. For the rest of the RFQ, see our RFQ best practices, and if a plate unit might suit the duty better, compare plate and shell and tube exchangers first.

Ready to get exchanger quotes you can compare line by line? Start a free 14 day ChemCapital trial, with no credit card needed.