Home › Industries we serve › HVAC & District Cooling
Gaskets for HVAC and district cooling
District cooling plants, data centres, hotels and large buildings move chilled and condenser water through large pipes, chillers, pumps and cooling towers. Joints see vibration, thermal movement and treated water, and a leak in a plant room stops the cooling. We supply QGER gaskets, Garlock expansion joints and insulation kits for every part of the system.
Request a quoteWhere our gaskets are used
| Representative image | Gasket / seal | HVAC / district cooling use | Typical construction | HVAC / district cooling applications | Typical standards / specifications |
|---|---|---|---|---|---|
 | EPDM Chilled-Water Flange Gasket | Primary elastomeric sealing for chilled-water and condenser-water flanges; excellent water and aging resistance when the compound is correctly selected. | Full-face or ring EPDM gasket; plain or fabric-reinforced sheet. | Central chilled-water headers; condenser-water loops; cooling towers; pumps; strainers; valves; heat-exchanger connections; district cooling plant utility piping. | ASME B16.21; EN 1514-1; mating flanges ASME B16.5 / B16.47. ASME B31.1 commonly applies to central/district heating and cooling systems; ASME B31.9 may govern building-side HVAC piping. AWWA C207 may apply to large waterworks-style steel flanges. |
| NBR / Nitrile Rubber Flange Gasket | Oil-resistant elastomeric sealing for water/glycol systems and equipment auxiliaries where mineral oils or lubricants may be present. | Full-face or ring NBR gasket; plain or reinforced sheet depending on flange loading. | Chiller and pump auxiliaries; lubrication systems; glycol loops; compressor auxiliaries; selected condenser-water and equipment flanges where NBR compatibility is appropriate. | ASME B16.21; EN 1514-1; ASME B16.5 / B16.47 flange interfaces; ASME B31.1 or B31.9 depending on system scope. Equipment/OEM fluid-compatibility limits govern. |
| Neoprene / Reinforced Rubber Flange Gasket | Flexible sealing for water, weather-exposed plant piping and vibration-prone equipment connections. | Neoprene/chloroprene rubber; plain or cotton/fabric reinforced; ring or full-face configuration. | Cooling towers; pump connections; condenser-water systems; outdoor chilled-water equipment; HVAC plant skids; low-pressure utility water systems. | ASME B16.21; EN 1514-1; ASME B31.1 / B31.9 at piping-system level. Flange/OEM specifications govern hardness and reinforcement. |
 | Large-Diameter Pipe-Joint / Push-On Elastomeric Gasket | Provides flexible watertight sealing in buried or large-diameter district-cooling distribution pipelines. | Molded EPDM/SBR/NBR joint ring with pipe-system-specific lip, bulb or compression geometry. | Buried chilled-water transmission mains; district cooling distribution networks; make-up water and utility networks; pipe joints requiring angular deflection or movement. | ISO 4633 where applicable to water-pipeline rubber joint rings; EN 681-1 where adopted; pipe-system manufacturer specification governs geometry. AWWA standards may apply depending on pipe material and joint system. |
 | Grooved Coupling Gasket | Seals grooved mechanical couplings widely used in HVAC chilled-water and condenser-water piping. | Molded elastomer C-shaped or pressure-responsive coupling gasket, normally EPDM for water service, with proprietary groove geometry. | Plant-room chilled-water piping; condenser-water loops; cooling towers; pump skids; branch distribution; equipment connections and retrofit work. | AWWA C606 for grooved and shouldered joints where applicable; coupling-manufacturer specification/listing controls gasket profile, pressure rating and compound. ASME B31.9 or B31.1 applies at piping-system level. |
 | CNAF / Compressed Fibre Gasket | General-purpose sealing for water, compressed air, oils and plant utility services. | Compressed non-asbestos fibre sheet with synthetic/inorganic fibres, fillers and elastomeric binder. | Utility-water lines; compressed-air systems; pump and valve flanges; chiller auxiliaries; equipment skids; low-pressure service piping. | ASME B16.21; EN 1514-1; ASME B31.1 / B31.9 at system level; purchaser/OEM material specification. |
 | PTFE / ePTFE Flat Gasket | Chemically resistant sealing for water-treatment chemicals, inhibitors, glycol, acids/alkalis and corrosion-sensitive services. | Virgin/filled PTFE, restructured PTFE or expanded PTFE flat gasket. | Chemical dosing skids; corrosion-inhibitor systems; side-stream filtration; glycol treatment; cleaning systems; cooling-tower chemical feed; specialty equipment flanges. | ASME B16.21; EN 1514-1; ASME B16.5/B16.47 interfaces; ASME B31.1 or B31.9 at system level. Chemical compatibility and creep/permeation limits govern. |
| PTFE Envelope Gasket | Provides a chemically inert wetted surface over a compressible core for aggressive water-treatment and cleaning chemicals. | PTFE envelope around compressed non-asbestos fibre or flexible graphite core. | Chemical-treatment vessels; dosing skids; acid/caustic cleaning systems; water-treatment equipment; corrosion-sensitive flanges and specialty plant equipment. | ASME B16.21 where standard flat-gasket dimensions apply; EN 1514-1 for compatible PN flanges; equipment/OEM drawing for custom shapes. |
 | Spiral Wound Gasket - QSW3 / QSW4 | Higher-pressure and higher-temperature sealing for steam, hot-water, thermal-energy and specialty utility systems associated with central cooling plants. | Profiled metal winding with graphite, PTFE or mica filler; QSW3 uses an outer ring and QSW4 uses inner and outer rings. | Steam-driven or absorption-chiller auxiliaries; district-energy heat-recovery systems; higher-pressure hot-water service; pressure vessels; utility steam and condensate where present. | ASME B16.20; ASME B16.5/B16.47 mating flanges; ASME B31.1 at central/district energy system level; project piping class governs filler and winding metallurgy. |
 | Camprofile / Kammprofile Gasket | Severe-service flange and exchanger sealing where pressure/temperature cycling or limited bolt load requires high recovery. | Grooved metallic core with graphite or PTFE facing; optional guide ring. | Large chillers and heat exchangers; high-duty thermal-storage interfaces; steam/hot-water auxiliaries; large equipment nozzles and cyclic service connections. | ASME B16.20 for grooved metal gaskets with covering layers; ASME B16.5/B16.47 interfaces; TEMA/OEM requirements for shell-and-tube exchangers; ASME BPVC Section VIII where applicable. |
 | Metal-Jacketed / Heat-Exchanger Gasket | Seals shell-and-tube heat exchangers, condensers and large equipment where a metallic shell protects a resilient filler. | Thin metallic jacket around graphite or another resilient filler; single/double-jacketed and ribbed configurations. | Chiller condensers/evaporators of applicable shell-and-tube design; heat-recovery exchangers; condenser-water heat exchangers; thermal storage equipment; utility exchangers. | ASME B16.20 where applicable; TEMA exchanger requirements; ASME BPVC Section VIII where the exchanger is pressure equipment; equipment drawing controls geometry. |
 | Plate Heat-Exchanger Gasket | Seals individual plates and separates primary/secondary chilled-water circuits in gasketed plate-and-frame heat exchangers. | Precision-molded EPDM, NBR or FKM/Viton perimeter gasket clipped or bonded to the plate. | District cooling energy-transfer stations; building interface heat exchangers; thermal-energy-storage loops; condenser-water heat recovery; chiller-plant secondary circuits. | Heat-exchanger OEM drawing/specification governs gasket geometry and compression. AHRI 400/401 applies to liquid-to-liquid heat-exchanger performance ratings, not gasket dimensions. Elastomer compatibility governs compound selection. |
 | Precision O-Rings / Molded Elastomer Seals | Compact static and dynamic sealing in chillers, pumps, valves, instruments, actuators and refrigerant/water auxiliaries. | Precision-molded EPDM, NBR, FKM/Viton, silicone, FFKM or specialty elastomer; backup rings where required. | Chiller service connections; pump housings; control valves; actuators; sensors; flow meters; glycol skids; water-treatment equipment. | ISO 3601 series for O-ring dimensions, housing dimensions and quality acceptance. Equipment/OEM specification governs elastomer compound and refrigerant/oil/water compatibility. |
 | Mechanical Seal | Controls leakage around rotating shafts of chilled-water, condenser-water and utility pumps. | Stationary and rotating seal faces with springs and secondary elastomeric seals; single or double arrangement depending on pump duty. | Primary chilled-water pumps; secondary distribution pumps; condenser-water pumps; cooling-tower pumps; heat-recovery and water-treatment pumps. | Pump-OEM specification governs. ISO 5199 may apply to industrial centrifugal pumps; project pump specification and seal-face/elastomer compatibility control final selection. |
 | Graphite / PTFE Compression Packing | Controls leakage around valve stems and selected slower-speed pump or rotary shafts. | Braided PTFE or graphite packing; preformed graphite rings for selected valves. | Isolation/control valves; cooling-water equipment; chemical-treatment pumps; older pump stuffing boxes; utility and maintenance applications. | Valve/pump OEM specification and FSA/ESA packing installation guidance. ASME B31.1/B31.9 governs the connected piping system where applicable. |
 | Non-Metallic Expansion Joint / Flexible Coupling | Absorbs thermal movement, vibration, pumping surges, settlement and misalignment in chilled-water and condenser-water piping. | Engineered rubber/fabric non-metallic flexible joint with flanged ends; metallic bellows may be used in other expansion-joint designs. | Pump suction/discharge; chiller connections; cooling towers; large chilled-water headers; condenser-water piping; district cooling plant and network interfaces. | ASTM F1123 for arch-type non-metallic expansion joints where specified; EJMA for metallic bellows. ASME B31.1 for central/district heating and cooling systems or B31.9 for building-side HVAC piping. |
 | Flange Insulation Kit / Insulating Gasket | Electrically isolates flanged joints to help control galvanic corrosion and support cathodic-protection schemes. | High-strength insulating gasket plus insulating sleeves, insulating washers and steel washers. | Buried steel district-cooling distribution networks; mixed-metal connections; plant boundary isolation points; cathodically protected transmission piping. | ASME B16.5/B16.47 or AWWA C207 flange dimensions as applicable; AMPP/NACE SP0286 where electrical isolation of cathodically protected piping is required; project corrosion-control specification governs. |
 | Butterfly Valve Resilient Seat / Seat Seal | Provides bubble-tight or low-leakage isolation in large chilled-water and condenser-water valves. | Molded EPDM, NBR or other elastomeric liner/seat; bonded or replaceable depending on valve design. | Large chilled-water isolation valves; condenser-water lines; cooling towers; energy-transfer stations; distribution-network sectional valves. | AWWA C504 for rubber-seated butterfly valves in applicable water-service duties; ASME B16.34 or valve-OEM specification where applicable. Valve manufacturer controls exact seat geometry and compound. |
 | Oil Seal / Bearing Isolator | Retains lubricant and prevents ingress of water, dust and contaminants at rotating shafts and bearing housings. | Elastomeric radial-shaft lip seal or non-contact labyrinth-style bearing isolator; solid or split configurations. | Chillers; cooling-tower gearboxes/fans; pumps; motors; drive equipment; compressor auxiliaries and rotating machinery. | ISO 6194 series for rotary-shaft lip seals; equipment/OEM bearing and shaft requirements govern bearing-isolator selection. |
 | Pump Diaphragm | Flexible pumping barrier for chemical dosing and water-treatment liquids used in cooling-water management. | ePTFE wetted face bonded to reinforced elastomer backing or other OEM-specific PTFE/elastomer diaphragm construction. | Biocide dosing; corrosion-inhibitor injection; pH-control chemicals; glycol/additive dosing; side-stream treatment; cooling-tower water-treatment skids. | Pump-OEM dimensional/material specification governs. API 675 applies to controlled-volume metering pumps where specified; it does not universally apply to all diaphragm-pump designs. |
These are typical starting points. Final selection depends on your service conditions and is confirmed with QGER engineering before manufacture.
Points to watch
- Tell us the water treatment chemicals. Some biocides and inhibitors shorten rubber life.
- Expansion joints at pumps cut noise and vibration in the building. Send pump flange sizes with your enquiry.
- Large-diameter mains often use non-standard flanges. Send drawings with bolt-hole positions.
Get the right gasket for your plant
Send us your drawing, standard, size and material. We reply promptly.
Request a quoteOther industries
Oil & Gas · Refining · Petrochemical & Chemical · Power Generation · Water & Desalination · Renewable Energy · Mining & Phosphates · Marine & Shipbuilding · Aviation & Aerospace · Automobile Manufacturing · Cement · Fertilizer, Ammonia & Hydrogen · Food, Beverage & Sugar · Pharmaceutical · Pulp & Paper · Steel & Metals