1. Define both streams
Identify hot and cold media, composition, concentration and any solids or contaminants. Supply properties where the fluid is a mixture or a non-standard product. Include phase and any change of phase through the exchanger.
Prepare an engineering selection enquiry
A useful enquiry describes the process, the operating envelope and the installation—not only the exchanger model.
Overview
2. State the thermal programme
Provide mass or volume flow with units, inlet temperatures and required outlet temperatures. If the required duty is known, include it. Identify which values are fixed and which may be adjusted.
3. Separate operating and design conditions
Operating pressure and temperature describe normal service; design values define the specified mechanical conditions. State both for each side, including vacuum, upset conditions and differential-pressure cases where relevant.
4. Specify hydraulic limits
Give allowable pressure drop separately for each side and explain whether the allowance includes connections and external piping. For gases, identify the reference conditions used for volumetric flow.
5. Describe the installation
Include available footprint, height, maintenance clearance, nozzle interfaces, flange requirements, supports and orientation. Existing datasheets and drawings are useful for retrofit assessment.
6. Define the supply documentation
State the required design code, inspection requirements and documentation scope. Discuss material records, pressure-test records, drawings and operating instructions as part of the project specification.
Engineering questions
Is a model number enough to quote a replacement?
No. The same nominal model may have different plate counts, materials, nozzles and design conditions. Send the datasheet, nameplate and arrangement drawing.
What happens if an outlet temperature is not fixed?
Identify the required heat duty and the adjustable stream. The selection can then assess the temperature programme against the process constraints.
Related engineering topics
Send Your Process Data for Heat Exchanger Selection
Provide both fluids, flow rates, inlet and outlet temperatures, operating and design pressures, allowable pressure drop and material requirements. For an existing installation, include the nameplate and arrangement drawing.