Product Overview
Reliable custom rubber parts for industrial applications
Quick Answer
This EPDM sealing gasket for HVAC is designed for duct flanges, access panels, filter frames, fan housings, air-handling units and equipment enclosures. Flat gaskets, sponge strips, solid profiles, molded frames and extruded seals are available. Dimensions, thickness, cross-section, hardness, color, adhesive backing, tolerance and packaging can be customized.
An EPDM sealing gasket for HVAC is an elastomer sealing component used in ductwork, air-handling units, ventilation equipment, access panels and flange connections. It helps reduce air leakage, dust ingress, vibration transfer and moisture entry under controlled compression. Dimensions, profile, hardness, color, tolerance and packaging can be customized according to drawings, samples or installation requirements.
Product Overview
The EPDM sealing gasket for HVAC is designed for static sealing in heating, ventilation and air-conditioning systems. EPDM is commonly selected for HVAC applications because it offers practical resistance to weathering, ozone, moisture and temperature variation. Depending on the installation position, the gasket can be supplied as a flat gasket, strip gasket, duct flange gasket, access-door gasket, molded profile seal or extruded sealing profile. It can be installed between duct flanges, equipment covers, panels, frames or housings to improve air sealing and reduce metal-to-metal contact. The final gasket design should be confirmed according to the duct size, flange structure, compression method, airflow conditions and environmental exposure.
Key Features
- EPDM rubber gasket designed for HVAC duct, enclosure, panel and equipment sealing.
- Helps reduce air leakage, dust ingress, moisture entry and vibration transfer.
- Suitable for indoor, outdoor and weather-exposed HVAC equipment interfaces.
- Available as flat gaskets, flange gaskets, strip seals, molded gaskets and extruded profiles.
- Dimensions, thickness, cross-section and hole pattern can be customized according to drawing.
- Shore A hardness can be reviewed according to compression and installation requirements.
- Material formulation can be adjusted according to temperature, ozone exposure and sealing requirements.
- Prototype samples and dimensional inspection requirements are available upon request.
Product Specifications
| Attribute | Value |
|---|---|
| Product Name | EPDM Sealing Gasket for HVAC Pipe Flanges |
| Also Known As | HVAC Pipe Flange Gasket / Chilled Water Gasket / Heating Circuit Flange Seal / EPDM Water Gasket |
| Material | EPDM (Ethylene Propylene Diene Monomer) — carbon-black reinforced |
| Gasket Types | Ring-type (RF, no bolt holes) / Full-face (FF, with bolt holes) / Full-face with location lug |
| Color | Black |
| Hardness | Shore A 60 ± 5 (standard) |
| Nominal Bore Range | DN15 (½”) to DN600 (24″) |
| Thickness | 1.5 mm, 2.0 mm, 3.0 mm, 4.5 mm, 6.0 mm |
| Temperature Range | -50°C to +150°C |
| Pressure Rating | PN6 / PN10 / PN16 standard; PN25 available |
| Flange Standards | EN 1092-1, ANSI B16.21 Class 150, DIN 2690, BS 4504, JIS B2401 |
| Fabrication | Die-cut, water-jet cut, compression moulded |
| Certifications | RoHS, REACH; WRAS-approved compound available (UK potable/closed circuit water) |
Why EPDM Is the Universal HVAC Gasket Compound？
HVAC hydronic systems expose pipe flange gaskets to a demanding combination of conditions that eliminates many alternative compounds. The gasket must resist continuous water and glycol contact across a temperature range from near-freezing chilled water circuits (+4°C to +12°C) through ambient heating circuits (+60°C to +90°C) up to low-pressure steam at +130°C to +150°C. It must maintain sealing contact stress over multi-year service intervals without re-torquing — a critical requirement in HVAC systems where pipe flanges are frequently installed in congested plant rooms with restricted access. And in the large fraction of HVAC systems with external piping — cooling towers, rooftop condensers, external expansion tanks — the gasket must resist atmospheric ozone and UV radiation without surface cracking and hardening that would cause premature leakage.
EPDM satisfies all these requirements simultaneously:
- Water resistance: Negligible swell and property change in continuous cold water, hot water, and glycol-inhibited water contact — maintains original dimensions and sealing force throughout service life
- Steam resistance: Rated to +150°C continuous; suitable for low-pressure steam distribution systems serving HVAC plant without compound change
- Ozone and UV resistance: EPDM is inherently ozone-resistant — the polymer backbone has no double bonds susceptible to ozone attack; will not surface-crack in outdoor installations
- Compression set resistance: Premium EPDM compound retains ≥ 75% elastic recovery after sustained compression, maintaining bolt load and sealing contact stress over years of service without re-torquing
- Glycol compatibility: Fully resistant to ethylene glycol and propylene glycol antifreeze/corrosion inhibitor mixtures used in chilled water and heating circuits
- Chemical resistance: Compatible with the pH buffers, corrosion inhibitors, biocides, and scale inhibitors used in HVAC closed circuit water treatment programs
HVAC System Circuits — Media & Temperature Reference
| HVAC Circuit | Media | Operating Temp | EPDM Suitability |
|---|---|---|---|
| Chilled Water Primary Loop | Chilled water or glycol/water | +4°C to +12°C flow; +12°C to +18°C return | ✅ Excellent |
| Chilled Water Secondary Loop | Chilled water, glycol/water | +4°C to +20°C | ✅ Excellent |
| Low-Temperature Hot Water (LTHW) | Treated water, glycol/water | +60°C to +80°C flow; +40°C to +60°C return | ✅ Excellent |
| Medium-Temperature Hot Water (MTHW) | Treated water | +80°C to +120°C | ✅ Excellent |
| High-Temperature Hot Water (HTHW) | Pressurized treated water | +120°C to +150°C | ✅ Suitable |
| Condenser Water | Open circuit cooling tower water | +25°C to +45°C | ✅ Excellent |
| Cooling Tower Pipework | Open circuit water, UV-exposed | Ambient +15°C to +45°C | ✅ Excellent (UV-resistant) |
| Domestic Cold Water (DHWS) | Potable cold water | +5°C to +20°C | ✅ WRAS-approved grade |
| Domestic Hot Water (DHWS) | Potable hot water | +60°C to +65°C | ✅ WRAS-approved grade |
| Low Pressure Steam | Steam condensate | +100°C to +150°C | ✅ Suitable |
| Steam Condensate Return | Condensate water | +80°C to +100°C | ✅ Excellent |
| Compressed Air (HVAC controls) | Dry/oily compressed air | Ambient to +80°C | ✅ Suitable (dry air) |
Dimensional Standards Reference
EN 1092-1 EPDM Ring Gasket — Selected HVAC Sizes (PN10/PN16)
| DN | Gasket ID (mm) | Gasket OD (mm) | Thickness | Bolts |
|---|---|---|---|---|
| DN15 | 16 | 38 | 2.0 mm | 4 × M12 |
| DN20 | 22 | 48 | 2.0 mm | 4 × M12 |
| DN25 | 27 | 52 | 2.0 mm | 4 × M12 |
| DN32 | 35 | 62 | 2.0 mm | 4 × M12 |
| DN40 | 41 | 68 | 2.0 mm | 4 × M12 |
| DN50 | 53 | 88 | 2.0 mm | 4 × M16 |
| DN65 | 66 | 105 | 3.0 mm | 4 × M16 |
| DN80 | 80 | 122 | 3.0 mm | 8 × M16 |
| DN100 | 104 | 148 | 3.0 mm | 8 × M16 |
| DN125 | 129 | 178 | 3.0 mm | 8 × M16 |
| DN150 | 155 | 212 | 3.0 mm | 8 × M20 |
| DN200 | 206 | 268 | 3.0 mm | 8 × M20 |
| DN250 | 257 | 320 | 4.5 mm | 12 × M20 |
| DN300 | 307 | 370 | 4.5 mm | 12 × M20 |
| DN400 | 408 | 482 | 4.5 mm | 16 × M24 |
| DN500 | 509 | 590 | 4.5 mm | 20 × M24 |
| DN600 | 610 | 698 | 6.0 mm | 20 × M27 |
EPDM Compound Properties — HVAC Grade
| Property | Test Method | Value |
|---|---|---|
| Hardness | ISO 48-4 / Shore A | 60 ± 5 |
| Tensile Strength | ISO 37 | ≥ 9 MPa |
| Elongation at Break | ISO 37 | ≥ 300% |
| Compression Set | ISO 815 (22h @ 70°C) | ≤ 18% |
| Volume Change in Water | ISO 1817 (70°C, 24h) | ≤ +4% |
| Heat Aging | ISO 188 (70h @ 100°C) | ≤ ±10% property change |
| Ozone Resistance | ISO 1431-1 (100 pphm, 40°C) | No cracking |
| Low-Temperature Flexibility | ISO 812 | -50°C (TR10 ≤ -40°C) |
| Density | ISO 2781 | 1.15–1.25 g/cm³ |
| Temperature Range | Continuous | -50°C to +150°C |
Comparison — EPDM vs. Alternative Gasket Compounds for HVAC
| Property | EPDM | NBR | Butyl (IIR) | FKM | Silicone (VMQ) |
|---|---|---|---|---|---|
| Water / HVAC water | ✅ Excellent | ❌ Poor swelling | ✅ Good | ✅ Good | ✅ Good |
| Glycol/inhibitor solutions | ✅ Excellent | ❌ | ✅ Good | ✅ Good | ✅ Good |
| Steam to +150°C | ✅ Excellent | ❌ | ✅ Good | ✅ Excellent | ✅ Good |
| Ozone / UV resistance | ✅ Excellent | ❌ Poor | ✅ Good | ✅ Excellent | ✅ Excellent |
| Compression set | ✅ ≤ 18% | ✅ Good | ✅ Good | ✅ Very good | ⚠️ Moderate |
| Temperature range | -50°C to +150°C | -40°C to +100°C | -40°C to +130°C | -20°C to +200°C | -60°C to +250°C |
| WRAS (drinking water) | ✅ Available | ❌ | ❌ | ✅ Available | ✅ Available |
| Cost | ✅ Low | ✅ Low | ✅ Low | ❌ High | ❌ High |
| HVAC recommendation | ✅ First choice | ❌ Not suitable | ✅ Steam alternative | ⚠️ Overkill for HVAC | ⚠️ Cost-prohibitive |
Applications
EPDM sealing gaskets for HVAC are used in duct flanges, ventilation ducts, air-handling units, fan housings, filter frames, damper frames, access doors, inspection panels, rooftop units and HVAC enclosure assemblies. The gasket helps improve sealing between sheet-metal or equipment surfaces while reducing vibration, rattling and dust entry. Solid EPDM can be reviewed for firm compression requirements, while sponge EPDM can be considered where lower closing force or better surface conformity is needed. The final gasket profile should match the flange width, groove structure, compression gap, airflow condition, indoor or outdoor exposure and expected maintenance cycle.
Customization Options
Custom EPDM sealing gaskets for HVAC can be developed from 2D drawings, 3D models, dimensional sketches or physical samples. Buyers can specify flat cut gaskets, continuous sealing strips, molded frames, extruded profiles, sponge profiles, adhesive-backed gaskets or punched flange gaskets. Available customization items include length, width, thickness, cross-section, hole pattern, Shore A hardness, color, tolerance, adhesive backing and packaging. Please provide the installation position, compression gap, surface condition, operating temperature, exposure to moisture or ozone, required quantity and estimated annual demand. Tooling cost depends on the drawing and product structure.
What Information Should Buyers Provide for a Quote?
- Product drawing or physical sample
- Dimensions and tolerances
- Rubber material
- Shore A hardness
- Operating temperature
- Contact media
- Application environment
- Required quantity
- Estimated annual volume
- Compliance requirements
- Packaging requirements
FAQ
What is an EPDM sealing gasket for HVAC used for?
An EPDM sealing gasket for HVAC is used to seal duct flanges, access panels, air-handling units, fan housings, filter frames and equipment enclosures. It helps reduce air leakage, dust entry, moisture ingress, rattling and vibration transfer between assembled HVAC components.
Why is EPDM commonly used for HVAC gaskets?
EPDM is commonly selected for HVAC sealing because it provides practical resistance to ozone, weathering, moisture and temperature variation. It is suitable for many ventilation, ducting and outdoor equipment applications where petroleum oil or fuel exposure is not present.
Can the gasket profile be customized?
Yes. EPDM HVAC gaskets can be supplied as flat gaskets, flange gaskets, sponge strips, solid strips, bulb seals, lip seals, D-shape profiles, P-shape profiles or molded frames. The final profile should match the compression gap, mounting method and sealing surface.
Is sponge EPDM or solid EPDM better for HVAC sealing?
Sponge EPDM is often used when the gasket must compress easily and conform to uneven sheet-metal surfaces. Solid EPDM is better when higher mechanical strength, firmer compression or more durable edge support is required. The best choice depends on the installation design.
Can adhesive backing be added to EPDM HVAC gaskets?
Adhesive backing can be reviewed for applicable flat gaskets, strips and profiles. It may help with assembly positioning before final compression. The adhesive type should be selected according to the mounting surface, temperature, storage conditions and installation process.
Are samples available before mass production?
Samples are available upon request. Sample planning depends on the gasket profile, dimensions, material, hardness, tooling requirements and quantity. Please provide a drawing, sketch or physical sample so the EPDM sealing gasket for HVAC can be reviewed before batch production.
Request a Custom Quote
Send your EPDM HVAC gasket drawing, 3D model, dimensional sketch or physical sample for technical review. Please include the gasket profile, size, thickness, hardness, compression gap, installation position, operating environment, quantity, annual demand and packaging requirements so we can prepare a practical quotation.
