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What Data Should You Send Before Requesting a Heat Exchanger Quote? Thermal, Mechanical, Material and Project Information

Author: HeatEx Direct Editorial Team
Read: 10 minutes
What Data Should You Send Before Requesting a Heat Exchanger Quote? Thermal, Mechanical, Material and Project Information

Many buyers think the information needed for a quote is just the model, the quantity and a target price. For a heat exchanger, that is far from enough. A heat exchanger quote is really an engineering model that the supplier builds from your data: how the fluids flow, how heat is transferred, whether the materials are suitable, whether the unit can withstand the pressure, whether it fits on site and whether it can be maintained. The more complete the data, the closer the quote is to your real purchase cost. The vaguer the data, the more the quote becomes an estimate that cannot be compared with others.

If you plan to request quotes from Chinese suppliers, start by sorting your information into five groups: thermal data, mechanical data, material and corrosion data, operation and maintenance data, and commercial and delivery data. The RFQ form already splits these into basic information, product type, quantity, delivery time, additional notes and file uploads. For complex projects, we recommend uploading an Excel or PDF datasheet as well.

1. Thermal Data: Size and Heat Transfer Capacity

Thermal data is the first layer of a quote. At minimum, the supplier needs the fluids on the hot and cold sides, flow rates, inlet and outlet temperatures, pressures, phase and allowable pressure drop. For many projects, flow rates and temperatures matter more than "heat transfer area", because area is a result of the calculation, not an operating condition. TEMA's public standards page says its specification sheet was updated to define heat exchanger design requirements better, which matches purchasing experience: suppliers need inputs they can calculate with, not vague results.

Data itemExampleNote
Hot-side fluidHot water, thermal oil, steam, process gasFor mixtures, give the main components
Cold-side fluidCooling water, seawater, glycol, airPoint out seawater and chloride-bearing water
Flow rate120 m³/h or 100,000 kg/hState whether it is mass or volume flow
Temperatures95 °C to 65 °C; cold side 30 °C to 45 °CIf you only know the heat duty, say so
PressuresOperating, design and test pressureAffects the pressure vessel code
Pressure dropMaximum allowable kPa on each sideLinked to pump power and the number of channels or tube passes

2. Mechanical Data: Can the Unit Be Built and Accepted?

Mechanical data covers the design code, flange standard, nozzle sizes, installation orientation, pressure vessel certification, non-destructive testing, hydrostatic testing, painting, insulation and packing. ASME's public description of BPVC Section VIII Division 1 shows that it covers the design, fabrication, inspection, testing and certification of pressure vessels operating at internal or external pressures above 15 psig. You do not need to quote code clauses in your first RFQ, but state clearly whether the project requires an ASME U stamp, PED, GB standards, a project specification or third-party witnessing.

For shell-and-tube heat exchangers, mechanical data usually weighs more than for plate units, because tubesheets, the shell, the tube bundle, expansion joints, supports and the space needed to pull the bundle all have to be considered early. For TP welded plate heat exchangers, the welded construction, pressure rating and cleaning method are the key points of the quote.

3. Material and Corrosion Data: The Biggest Source of Price Differences

Large price differences between suppliers often come from different material assumptions rather than different margins. 304, 316L, titanium, duplex stainless steel, Hastelloy, copper-nickel, lined carbon steel and gasket materials such as EPDM, NBR and FKM all differ in cost and limits of use. Buyers can provide the chloride content, pH, sulfides, particles, viscosity, contaminants, cleaning agents, CIP temperature and whether food-grade or pharmaceutical-grade design is required.

Fluid riskWhat to statePossible effect
Seawater or brineChloride content, temperature, velocity, stagnant periodsMaterials, corrosion allowance, strainers
Oils or organic solventsFlash point, viscosity, impurities, pressureSeals, welded construction, explosion protection
Food or pharmaceuticalCleaning agents, hygienic requirements, dead-leg limitsSurface finish and cleanability
Slurries or fibersSolids content, particle size, viscosityWide-gap or tubular designs
Condensing steamSteam pressure, condensate removalSteam traps and water hammer risk

4. Operation and Maintenance Data: Life-Cycle Cost

A U.S. Department of Energy (DOE) note on side-stream filtration for cooling towers explains that fouling and scaling form an insulating film on heat transfer surfaces and increase the energy chillers need to remove heat. Side-stream filtration can reduce problems related to suspended solids and microorganisms, but it does not replace chemical water treatment. The same idea applies to most heat exchanger purchases: besides the equipment price, look at cleaning intervals, rising pressure drop, spare parts and downtime costs.

Buyers can state whether the current unit fouls often, whether cleaning in place is needed, whether the unit may be opened, their spare parts policy, the expected run length, the shutdown window and the skills of the maintenance team. For gasketed plate heat exchangers, maintenance focuses on plates, gaskets and the tightening dimension. For wide-gap welded plate heat exchangers, the key question is whether the design really suits fluids with particles, fibers or high viscosity.

5. Commercial and Delivery Data: Will the Supplier Quote Seriously?

Suppliers also judge the quality of an inquiry. A clear RFQ usually states the project location, target delivery date, quantity, required quote validity, whether spare parts are needed, payment terms, target certifications, the end user's industry, document language requirements and whether alternative designs are acceptable. Many Chinese suppliers answer vague inquiries with a very rough price first. When the data is complete, they are more willing to have engineers do a proper thermal calculation.

6. Recommended Order for Sending Data

Step 1: send the minimum data needed for a quote: fluids, flow rates, temperatures, pressures, quantity, industry and target delivery date. Step 2: add the boundary conditions: materials, corrosion, pressure drop, flanges, installation space, standards and certifications. Step 3: upload attachments: drawings, the old nameplate, photos, datasheets, P&IDs and project specifications. Step 4: ask suppliers to return a thermal summary, a material explanation, weights and dimensions, a list of delivery documents and a deviation list.

You can use the RFQ form for step 1 and submit the project description and attachments together. You can also browse the manufacturer list and the product catalog first to settle on the general product type before requesting quotes. The point is not to fill in everything at once, but to let suppliers know which data is fixed and which they need to ask about.

7. What to Write When Data Is Incomplete

Many real projects do not have complete data at the RFQ stage, and that is normal. What matters is not filling every cell of the table but separating what you know from what you do not. If you only know the hot-side fluid and inlet temperature but not the outlet temperature, state whether the goal is cooling, heating, heat recovery or condensing, and let the supplier tell you which boundary conditions are still needed. If you only know where the cooling water comes from but not the actual flow, give the pump capacity, pipe size or allowable pressure drop range, so the supplier can decide whether a conservative design is needed.

If you have no thermal data at all and only know that "the old unit must be replaced", the most valuable information is the old nameplate, photos of the unit, connection positions, available space, the reason for failure and past operating problems. Frequent fouling, leaks, high pressure drop or difficult cleaning are themselves selection signals. The supplier may recommend the same type again, or suggest changing from a gasketed plate unit to a wide-gap welded plate unit, from a plate unit to a shell-and-tube unit, or keeping a shell-and-tube unit with different materials or construction. Ask the supplier to explain any change of type rather than just giving you a model number.

8. Attachments Reduce Errors More Than Text

In an RFQ, attachments are often more useful than long descriptions. Prepare at least some of the following: a process datasheet, P&ID, site photos, the old nameplate, a sketch of the installation space, a nozzle orientation drawing, project specifications, material requirements, third-party inspection requirements and packing and shipping requirements. The RFQ form accepts common files such as images, PDF, Word, Excel and CSV, so you can submit scattered documents together.

Attachments still need explanation. If you upload a PDF without saying which document takes priority, the supplier may not know which version to follow. A better approach is to state the purpose of the RFQ, list each attachment and what it is for, say which parameters the supplier may recommend, and ask the supplier to list its assumptions in the quote. Even with incomplete data, this creates a technical record that both sides can follow.

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