Shell-and-tube heat exchangers
Thermal exchange equipment requiring process duty, pressure limits and material selection on both sides.
Shell-and-tube heat exchangers transfer heat between fluids separated by tube walls. The shell, tube bundle and channel arrangements manage pressure containment, heat-transfer area and access for maintenance.
Typical applications
Heating, cooling, condensation and evaporation duties across process plants use this exchanger family. Both fluid streams must be described to define the thermal duty.
Types and configuration choices
Tube material, bundle arrangement, allowable pressure drop and fouling conditions influence selection. Replacement bundles require the existing mechanical drawings and dimensional interfaces.
What should a shell-and-tube heat exchanger RFQ contain?
A shell-and-tube heat exchanger RFQ needs a thermal duty schedule, separate hydraulic limits for both sides and a mechanical design basis. Identify whether the purchase is a new exchanger, a complete replacement or a replacement bundle. These are different scopes even when they refer to the same plant tag. Provide the fluid identities and paired operating cases, then describe the required materials, interfaces, inspection and documentation. Mark unresolved process data as provisional. The thermal proposal should explain how it addresses the stated cases; a drawing that fits the available space is not by itself evidence that the exchanger will meet the process requirement.
For an installed exchanger, include the current datasheet, nameplate information, general arrangement and relevant drawings with their revisions. Explain whether the process duty has changed and whether the existing equipment suffered a service problem that needs investigation. Keep the replacement boundary explicit: a new bundle inside the retained shell has different interface and condition questions from a completely new vessel assembly. If the first RFQ is for budgeting, request a list of assumptions and the information required to firm up the proposal. That makes the next revision a controlled improvement rather than an unexplained change in specification or price.
Why must thermal duty and pressure drop be reviewed together?
The required heat transfer and the available pressure-drop allowances belong in the same comparison. Ask each bidder for a case schedule identifying the inlet and outlet conditions, flows, stated duty and calculated pressure drop on both sides. Specify the agreed basis for fouling and any margin through the project design documents, and ask the proposal to distinguish clean and specified service conditions where relevant. Do not treat an added surface area, a fouling assumption and a performance margin as interchangeable quantities. A bare statement of area cannot show whether a proposal meets the required outlets within the hydraulic limits.
An illustrative comparison is two offers for the same stated duty. One uses the buyer's summer cooling-water condition; the other assumes colder water and provides no summer case. Resolve that difference before deciding that one smaller unit is the better purchase. Similarly, keep the shell-side allowance separate from the tube-side allowance and make the calculation boundaries clear. Ask the responsible thermal reviewer to assess the offered cases and exceptions. The buyer's role in the RFQ is to supply consistent inputs and obtain comparable results, rather than infer a design from a general sizing rule or accept a calculation whose assumptions remain hidden.
How do mechanical arrangement and maintenance access affect selection?
The exchanger arrangement determines interfaces and the access required for inspection, cleaning and replacement. Request a general arrangement with nozzle locations, supports, overall dimensions and the spaces required by the proposed maintenance approach. State restrictions on bundle removal, channel access, lifting and installation orientation where they are known. Ask the proposal to identify the offered construction and how it addresses the project's access constraints. A removable part may still need a clear withdrawal path and handling resources; its name alone does not demonstrate that the installed location can accommodate the planned work.
For a replacement, compare mating connections, support positions and retained interfaces against the approved drawings. Record differences requiring changes to pipework, supports or insulation as part of the scope review. Distinguish design information provided by the buyer from a survey or verification service that is being requested. Photographs can help explain a restricted location, but critical geometry needs a documented dimensional basis. If access information is incomplete, ask bidders to identify their assumptions rather than declare the replacement interchangeable. The final purchasing comparison should include the agreed interface drawings and the work excluded from supply.
What do TEMA class and pressure-vessel code requirements establish?
TEMA class and a pressure-vessel construction code describe different aspects of the specification. The public TEMA guidance distinguishes Class R for severe petroleum duties, Class B for chemical process duties and Class C for general commercial duties. A class designation should come from the project's requirements and does not establish an individual exchanger's suitability by itself. State the applicable class and edition explicitly and request deviations against that basis. TEMA now uses a year-based edition designation; confirm the edition required by the project instead of assuming that a previous numbered edition is the current purchasing basis.
Where ASME Section VIII or another construction code is required, identify the applicable division, edition, certification requirements and governing project or jurisdictional basis. The public ASME description addresses pressure-vessel construction, inspection, testing and certification; it is not a thermal performance guarantee. Ask the offered scope to distinguish construction-code requirements from thermal acceptance, materials restrictions and any additional project specifications. Do not infer an authorized certification or an acceptable completed vessel from the presence of a standard's name in a sales description. The responsible reviewer should confirm the required evidence and any proposed exceptions before technical acceptance.
Which material and inspection records should accompany the offer?
Request a component material schedule and a proposed inspection and test plan alongside the technical response. The schedule should identify the specified and offered materials for the relevant pressure-retaining and wetted components, as well as seals, linings or other specified systems. Define material certificate and traceability requirements through the enquiry. Record alternatives as deviations rather than replacing the original specification silently. A certificate for one tube batch does not identify every material in the completed exchanger; the documentation should connect the required records to the actual component and equipment references.
Agree the required fabrication inspections, tests, acceptance references, witness or hold points and final reports in the project plan. Separate the purpose of a mechanical pressure test from the evidence needed for a thermal guarantee. Identify any third-party review, special cleaning or preservation requirements and ask whether those activities are included in the quotation. Request the final drawing and document index, including the records required at dispatch and those required for handover. Do not assume a catalogue listing establishes a particular test, certificate or manufacturing capability. Those facts must be confirmed for the equipment and scope actually offered.
How can buyers compare complete exchanger offers?
Compare the same equipment boundary, thermal cases, hydraulic limits, material schedule and mechanical requirements before comparing price. Record offered construction, maintenance access, design and test responsibilities, documentation, spare parts and deviations in a common matrix. Keep the proposed lead time tied to a stated starting event, such as approved drawings or another agreed milestone, without assuming those events have already occurred. Identify currency, delivery terms, named delivery location, packaging and quotation validity. Manufacturing country, dispatch location and the supplier's registered address are separate facts; ask for the origin evidence required by the project rather than treating them as interchangeable.
If one offer excludes engineering, a retained-shell condition assessment or installation changes, show those boundaries clearly. Avoid declaring a complete replacement and a bundle-only quotation commercially equivalent. Send the current datasheet, case schedule and interface drawings to Oillinko for manual review; availability, design suitability and commercial terms require confirmation for the actual enquiry. For further detail, use the bundle guide when retaining the existing shell, the pressure-vessel records guide when identifying an installed unit, and the compressor page when the cooling equipment is part of a compression package. These connected requirements can be coordinated without assuming that every item is supplied together.
Heat duty and temperatures
Provide paired hot-side and cold-side cases, with inlet temperatures, required outlet conditions and heat duty where established by the process design. State whether each fluid stays in one phase or includes boiling, condensation or another phase change. Distinguish an agreed process requirement from a preliminary estimate, and identify which values the thermal designer may calculate. Describe seasonal utility temperatures and relevant operating variation. Ask bidders to state their thermal basis and exceptions explicitly; quoting a heat-transfer area without the conditions used to select it does not establish the requested duty.
Flow on both sides
Give the mass or volumetric flow on each side with units, reference conditions and the fluid property information used by the process designer. Include composition and phase information where they affect the calculation. Pair the flows with their respective temperatures and pressures instead of assembling unrelated maxima into a fictional operating case. Identify minimum and maximum duties, startup cases requiring evaluation and any proposed future capacity. If a flow or property is uncertain, show its source and status so the proposal can identify what remains provisional.
Allowable pressure drop
Specify the allowable pressure loss separately for the shell side and tube side, and define the boundaries of those allowances. Clarify whether connecting pipework or other equipment is outside the exchanger calculation. Request calculated pressure drops at the same operating cases used for thermal selection, together with the assumptions behind them. A larger heat-transfer surface is not automatically an acceptable solution if the hydraulic limits, available space or maintenance arrangement differ. Keep a bidder's proposed allowance separate from the limit approved by the process team.
Tube and shell materials
Identify the specified material grades for tubes, shell, channels, tubesheets and other relevant wetted parts, along with gaskets and any approved corrosion allowance or lining. Provide fluid composition and relevant external exposure for materials review. An expression such as stainless steel does not define every component of an exchanger. Request the offered material schedule, traceability requirements and any substitutions against the enquiry. The material certificate requirement and its acceptance process should be explicit, with unresolved compatibility questions retained for the responsible project team.
How related requirements differ
Pressure vessels and separators: Pressure vessels contain fluids under specified design conditions. Separators use a vessel and selected internals to divide phases or remove entrained material, combining pressure containment with a defined process duty. Capacity, orientation, internals, materials and corrosion allowance vary by duty. The specified design code, inspection scope and nozzle interfaces belong in the equipment specification.
Storage tanks and tank accessories: Storage tanks hold liquids or other specified products within a defined storage design. Roofs, vents, level measurement and access fittings support operation and maintenance, but their configuration depends on the stored medium and tank arrangement. Atmospheric and specified-pressure tanks require different design bases. Roof type, materials, foundations, venting and accessory interfaces should be identified before comparing proposals.
Plate exchangers and air coolers: Plate heat exchangers transfer heat through formed plates separating fluid streams. Air coolers reject heat to ambient air through a finned-tube arrangement. The two technologies suit different utility availability and operating conditions. Gasketed or welded plate construction and different fan arrangements offer distinct maintenance and containment features. Compare thermal cases, materials, pressure limits and installation space.
Compare the complete supply scope
For shell-and-tube heat exchangers, compare complete exchanger supply separately from a bundle-only replacement. Identify channels, covers, supports, connections, insulation or other specified accessories, inspection activities and the final document package as included or excluded. For retained equipment, define responsibility for checking its condition and interfaces. Compare the offered thermal and hydraulic cases against the same datasheet revision, with deviations clearly listed. Manufacturing origin and dispatch location are separate from the named delivery point. Do not treat two prices as comparable until their equipment boundaries and evidence requirements are aligned.
Questions before requesting a quotation
What information should be available first? Start with the intended application and the current technical specification for shell-and-tube heat exchangers. In this category, the initial review includes heat duty and temperatures, flow on both sides, allowable pressure drop, tube and shell materials. Attach the relevant drawings or scope documents and identify any information still awaiting confirmation. This makes it possible to distinguish a preliminary enquiry from a fully defined purchasing or service requirement.
Can an alternative be accepted on size or price alone? A proposed alternative needs review against the required function, materials, interfaces and documented performance. Similar dimensions or a familiar brand name do not establish compatibility. State which requirements are mandatory and where an equivalent may be considered. Availability, lead time and supporting documents are confirmed for the actual offer rather than assumed from this catalogue.