O-Ring — EPDM — Metric

Description

EPDM O-Ring Supplier India | DIN 3771 Metric Sizes | Butterfly Valve Shaft Seal / Bonnet Seal | -40°C to +150°C | Hot Water / Steam / HVAC / Biocide Water | MOQ 1000 Nos | KELOR

Supplier: Krishna Industries (KELOR) – Ahmedabad, Gujarat, India
Established: 2017 | GSTIN: 24AKLPP6499B1ZT | IEC: AKLPP6499B
MOQ: 1000 Nos | Material: EPDM | Standard: DIN 3771
Hardness: 70 Shore A standard | Temperature: -40°C to +150°C

EPDM O-Ring Supplier in India — DIN 3771 Metric Sizes

Krishna Industries (KELOR), based in Ahmedabad, Gujarat, supplies EPDM O-rings in metric DIN 3771 sizes — 70 Shore A standard (60 and 80 Shore A on request) — temperature range -40°C to +150°C — for butterfly valve shaft seals, gate and globe valve bonnet seals, solenoid valve body seals, heat exchanger gaskets, and general hot water, steam, and HVAC sealing applications — GST invoice — MOQ 1000 Nos — Pan India dispatch from Ahmedabad.

EPDM is the correct O-ring material wherever the service fluid is hot water above 80°C, steam, HVAC chilled or hot water, biocide-treated cooling water, or ozone-containing atmosphere. Furthermore, it is the standard shaft seal material for CI butterfly valves used in HVAC and water treatment — the same EPDM material as the main resilient seat. Consequently, replacing butterfly valve shaft seals with the correct EPDM grade prevents the premature shaft seal failure that occurs when NBR shaft O-rings are incorrectly fitted in hot water or treated water BFV service.

EPDM vs NBR — When EPDM Is Mandatory

EPDM and NBR look identical as black O-rings. However, fitting the wrong material causes O-ring failure within days to weeks. Therefore, always confirm the service fluid before specifying O-ring material.

DIN 3771 Size System — How to Specify Your O-Ring

A DIN 3771 metric O-ring is specified as ID x CS — inner diameter in mm × cross section cord diameter in mm. For example, 40 x 3.5 means 40mm inner diameter and 3.5mm cord cross section. Furthermore, when ordering replacement O-rings for a valve, measure the old O-ring’s inner diameter and cord diameter with a calliper and specify these two numbers. Do not estimate — even 0.5mm error in ID causes either leakage (too small) or improper seating (too large).

Technical Specifications

Applications — Where EPDM O-Rings Are Used

Butterfly Valve Shaft Seals — HVAC and Water

EPDM O-rings fitted around the disc shaft (top and bottom) in CI and DI butterfly valves for HVAC chilled water, condenser water, and hot water service. The shaft seal O-ring is the first to show wear in a BFV — shaft weeping is the indicator. Furthermore, the shaft seal must match the main seat material — EPDM seat butterfly valve requires EPDM shaft O-rings — fitting NBR shaft O-rings in an EPDM seat BFV serving biocide-treated HVAC water causes premature shaft seal failure within one HVAC season.

Gate and Globe Valve Bonnet Seals — Hot Water

EPDM O-ring at bonnet joint for hot water gate and globe valves above 80°C. EPDM handles the continuous hot water temperature where NBR hardens and cracks. Moreover, steam condensate return line gate valve bonnet seals require EPDM — NBR fails within weeks in condensate service.

Solenoid Valve Body Seals — HVAC and Water Treatment

EPDM O-rings in HVAC AHU solenoid valve bodies — water service solenoid valves — ozone-treated water distribution solenoid valves. EPDM is the standard OEM solenoid valve body seal material for water and HVAC service — valve assemblers order 1000+ Nos per batch for assembly line production.

Plate Heat Exchanger Gaskets — HVAC

EPDM gaskets and O-rings for plate heat exchanger (PHE) frame sealing in HVAC chilled water and hot water systems. Very high volume — a single 200-plate PHE requires 200+ gaskets — HVAC equipment manufacturers order EPDM O-rings and gaskets in bulk quantities of 1000–10,000 Nos per batch.

Related Products — Krishna Industries (KELOR)

• NBR O-Ring — DIN 3771 Metric — nitrile O-ring for mineral oil, hydraulic oil, diesel, compressed air — where EPDM is not suitable
• Rubber Valve Seat — EPDM — complete EPDM seat assembly for butterfly valve replacement — the main seat that EPDM shaft O-rings complement
• Lever Operated Butterfly Valve — CI body EPDM seat BFV — valve that uses EPDM shaft O-rings supplied on this page
• Gear Operated Butterfly Valve — large bore CI/DI body EPDM seat BFV — larger shaft O-ring sizes
• Y Strainer — EPDM end cap gasket Y strainer for hot water and HVAC lines where the strainer cap seal also requires EPDM

Frequently Asked Questions

1. How do I identify whether my existing valve O-ring is EPDM or NBR?

Both EPDM and NBR are typically black and look identical by appearance. The only reliable way to confirm material is to check the valve manufacturer’s parts manual or maintenance manual — it will list the O-ring material for each position. Alternatively, apply a drop of mineral oil or diesel to the O-ring surface for 30 seconds — NBR is unaffected while EPDM swells visibly (slight surface bloating). However, this test damages the O-ring and it should then be discarded. The safest approach is to check the valve manual or contact the valve supplier with the valve model number for O-ring material confirmation.

2. Can EPDM O-rings be used in steam service?

Yes — EPDM handles steam to +150°C, making it suitable for low to medium pressure steam utility valve seals. However, steam O-ring applications require proper groove design — the O-ring groove must be sized to allow for EPDM’s thermal expansion at steam temperature, with approximately 10–15% less compression than cold water service to prevent over-compression and premature set. For steam above 150°C, specify Viton (FKM) O-rings which handle to +200°C. For high pressure steam above 180°C, metal gaskets are the standard solution rather than elastomeric O-rings.

3. Why is the MOQ 1000 Nos for EPDM O-rings?

EPDM O-rings at this MOQ are supplied for bulk buyers — valve assemblers fitting shaft O-rings on butterfly valve production lines, HVAC equipment manufacturers assembling AHU solenoid valves and heat exchangers, and maintenance stores stocking a full range of EPDM sizes for plant-wide butterfly valve maintenance. Bulk supply from a single source ensures consistent Shore A hardness and material grade across the entire batch — critical for valve assemblers who need consistent compression set behaviour across all units in a production run. For smaller quantities, individual replacement O-rings are available — WhatsApp your requirement.

4. What is the difference between 70 Shore A and 60 Shore A EPDM?

Shore A hardness measures the rubber’s resistance to indentation. 70 Shore A (standard) is suitable for most valve O-ring applications on machined metal surfaces with standard groove dimensions per DIN 3771. 60 Shore A (softer) provides better conformability on slightly rough or imperfect sealing surfaces — useful for older valve bodies where the O-ring groove surface has minor corrosion pitting or roughness. 80 Shore A (harder) provides better extrusion resistance at higher pressures — specify for PN16 and above or where extrusion into the O-ring gap is a risk at maximum operating pressure.

5. What is the MOQ for smaller quantities?

Standard MOQ for bulk EPDM O-ring supply is 1000 Nos per size. For maintenance and repair quantities below 1000 Nos, WhatsApp your O-ring dimensions (ID x CS in mm) and required quantity — we advise on availability and minimum supply quantity. GST invoice provided for all orders. Pan India dispatch from Ahmedabad.

Conclusion

Krishna Industries (KELOR) supplies EPDM O-rings in DIN 3771 metric sizes for butterfly valve shaft seals, gate and globe valve bonnet seals, solenoid valve body seals, heat exchanger gaskets, and HVAC sealing applications — 70 Shore A standard (60 and 80 Shore A on request) — temperature range -40°C to +150°C — hot water, steam, HVAC chilled and hot water, biocide-treated cooling water, ozone service — GST invoice — MOQ 1000 Nos bulk supply — Pan India dispatch from Ahmedabad. WhatsApp O-ring dimensions (ID x CS in mm) and quantity for pricing.