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Choosing plate heat exchanger gasket materials starts with the fluids inside the equipment—and the conditions the seals experience during operation, cleaning and shutdown.
NBR, EPDM, HNBR and FKM cover different applications. A material that performs well in lubricating oil may be unsuitable for a hot-water circuit. Even two gaskets labelled “EPDM” can have different temperature limits because they use different compounds.
For replacement gaskets, there is a second requirement: the seal must match the existing plate. Material compatibility and dimensional fit need to be checked together.
This guide compares the four materials and explains what information to confirm before ordering.
The table below provides a starting point for material selection. Suitability depends on the exact fluid, its concentration, operating temperature and gasket compound.
| Material | Applications to consider | Main selection concern |
|---|---|---|
| NBR, also called nitrile or Buna-N | Mineral oils, lubricants and suitable water duties | Confirm heat resistance and compatibility with cleaning chemicals |
| EPDM | Hot water, suitable steam duties and many water-based solutions | Generally unsuitable for mineral oils and petroleum fuels |
| HNBR, or hydrogenated nitrile | Oil duties requiring improved heat and ageing resistance compared with standard NBR | Verify the specific compound against the complete fluid mixture |
| FKM, including Viton™ compounds | Oils, hydrocarbons and selected chemical duties at elevated temperatures | Resistance to hot water, steam, bases and other chemicals varies by grade |
Use this comparison to shortlist materials, then confirm the exact compound against your operating conditions and the exchanger’s requirements.
If you already have a plate model or gasket reference, review the Aiprel replacement heat exchanger gaskets range for available material families, attachment options and representative compatible models. Confirm the exact plate variant and compound before ordering.
The most useful distinction between NBR and EPDM is often the fluid exposure.
NBR is commonly considered for oil service. EPDM is commonly considered for hot water and suitable steam applications. Neither choice should be based only on the name of the process.
For example, an oil cooler has both an oil circuit and a cooling circuit. The selection review should identify which fluids contact each seal, including any cleaning solution introduced during maintenance.
Ask a practical question before comparing prices: what will this gasket actually touch over a complete operating and cleaning cycle?
A fluid list containing only “water” or “oil” may be incomplete. Include additives, contamination that is reasonably expected in service, and the product name or technical data sheet where available.
HNBR offers improved heat and ageing resistance compared with standard NBR. It may be considered when an oil-service gasket needs capabilities beyond the existing NBR compound.
However, replacing NBR with HNBR should solve an identified problem. Before changing material, establish:
A hardened, swollen or cracked gasket provides useful evidence, but its appearance alone does not establish the cause. Keep the removed gasket and record the operating conditions so the supplier can review them together.
FKM is often considered for elevated-temperature oil and chemical service. EPDM remains a candidate for many aqueous applications.
FKM is a broad material family. Fluid resistance varies between compounds, and some special grades provide capabilities beyond conventional formulations. A generic “FKM” designation is therefore insufficient for a demanding chemical duty.
For hot water or steam, request confirmation for the exact FKM compound rather than applying a universal temperature cutoff. Likewise, an EPDM recommendation should identify the grade and its suitability for the proposed service.
The useful comparison is between two documented compounds under the same conditions.
Temperature limits vary by compound and operating conditions. When comparing quotations, ask for the exact gasket grade and its continuous operating limit, together with any restrictions on cleaning temperature and short-term exposure.
Record the normal operating temperature, the highest temperature reached during cleaning or sterilisation, and how long each peak lasts. Confirm these values against the fluids on both sides and the exchanger’s rated operating range.
For a duty operating at 140°C, for example, the number alone does not justify switching from EPDM to HNBR or FKM. The proposed compound needs to be suitable for the medium as well as the temperature.
For a new gasketed plate heat exchanger, review gasket selection together with plate material, design pressure and the equipment’s specified operating range. A material’s temperature rating does not establish the rating of the complete exchanger.
Cleaning-in-place conditions deserve their own entry on the enquiry sheet. A gasket may encounter a different chemical environment during cleaning than during normal production.
Provide the cleaning agent’s name, concentration, temperature, contact time and frequency. Include separate acid and alkaline stages where applicable, together with rinsing or sterilisation conditions.
Also describe shutdown exposure. Is the exchanger drained, left full of process fluid, or stored with a cleaning solution inside? Does it cool to outdoor temperature before restarting?
A useful operating summary could read:
Process fluid: [name and concentration]. Normal temperature: [range]. Maximum temperature: [value and duration]. Cleaning: [chemical, concentration, temperature and cycle duration]. Shutdown condition: [drained or retained fluid].
This gives the supplier more information than a request for “high-temperature, chemical-resistant gaskets.”
Once a suitable compound has been identified, confirm the replacement geometry.
Record the exchanger manufacturer, model, plate code and existing gasket reference. Where identification is incomplete, supply clear photographs of the nameplate, full plate, port area and gasket attachment features.
The details to verify include:
For an unidentified gasket, ask the supplier whether photographs are sufficient or whether a drawing, sample gasket or plate is needed. A visually similar outline is only a starting point.
If inspection also identifies damaged plates that need replacing, review the replacement heat exchanger plates range and confirm the plate and gasket as a matched combination. Include the plate code, port arrangement and required material in the enquiry.
Repeated leakage is a reason to review both the material and the assembly.
Compare the actual operating history with the original specification. Then inspect the plate grooves, gasket seating, plate condition and assembly records. Check the plate-pack closing dimension against the equipment manufacturer’s instructions.
Useful information for a failure review includes when the leak started, its location, whether it followed cleaning or reassembly, and any recent process changes.
Avoid ordering the same replacement automatically—or changing to a more expensive material—before identifying what needs to improve.
If the exchanger serves a food, beverage or drinking-water process, state the required market and contact conditions in the enquiry.
Ask for documentation that identifies the supplied compound and addresses the applicable requirements. A broad description such as “food-grade rubber” does not provide enough detail to compare quotations.
Keep this review alongside the chemical compatibility check: the supplier should address both the contact requirement and the operating and cleaning conditions.
A material change needs a review of both fluids, cleaning conditions and the available replacement profile. Ask the supplier to confirm the proposed compound for the complete duty before ordering.
Specify steam temperature and pressure, exposure duration, cycling frequency and the exchanger model. Request confirmation of the exact compound and equipment suitability.
Use the supplier’s documented identification system. If the material is uncertain, provide markings, purchase records or a sample rather than relying on colour alone.
Price does not establish suitability. Compare documented compatibility, dimensional fit and the requirements of the application before comparing cost.
Aiprel supplies replacement gaskets in NBR, HNBR, EPDM, high-temperature EPDM and FKM, with attachment configurations for different plate designs.
For a replacement enquiry, send the exchanger model or nameplate photograph, plate code, required quantity, fluids on both sides, operating temperatures and pressures, and cleaning details. Include any food or drinking-water contact requirements.
Contact Aiprel about your replacement gasket requirements and request confirmation of the proposed compound and matching profile. If the original gasket grade is unknown, include any available markings or purchase records so material selection and plate fit can be reviewed together.
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