Delivering Fluid Sealing Solutions Since 1972

D Ring Seals

D Ring Seals for rotary and reciprocating dynamic applications

M Barnwell Services are the largest independent manufacturer, stockist and distributor of fluid sealing products in the UK. With 50 million D Ring Seals, O Rings and Back-Up Rings in stock we supply to over 5000 customers globally every month – quickly and reliably.

Our range of D Ring Seals can be certified to FDA, EC1935/2004 & EC2023/2006 Regulations, and 3-A Standards grades. Materials include Nitrile (NBR)Hydrogenated Nitrile (HNBR)Viton™ (FKM/FPM)Perfluoroelastomer (FFKM)Ethylene Propylene (EPDM) and Silicone (VMQ). Full documentation and certificates can be provided.

M Barnwell Services can also provide D Ring Seals to suit DIN11851 fittings.

D Ring Seals

D shaped rubber seals present alternative elastomer solution to O Rings for use in rotary and reciprocating dynamic applications. They present identical sealing features as an O Ring. For high and low-pressure applications through a wide span of temperatures, D Rings are ideal.

D rings can usually be, therefore,  retrofitted into existing O Ring groove, the size is frequently established around the original O ring dimensions. The flat surface on the foundation of the D Ring ceases the seal from rotating and twisting, averting spiral failure frequently observed when O Rings are used in reciprocating applications. D Rings can be produced to typical O Ring sizes also as bespoke sizes for a particular application.

A collaboration of a low modulus material and small cross-section can assist to decrease friction in low-pressure applications. Selecting a higher modulus material with a lowered ratio of friction can decrease friction in high-pressure applications.

The table below shows a list of common DN sizes:

D shaped rubber seals

If you would like more information about our range, download our catalogue, visit the Seal Maker Page or contact a member of the team.

E & OE.


No limitation to dimensions with over 10,000 different sizes available from stock. DIN Sizes available


Nitrile (NBR), Viton® (FKM/FPM), Ethylene propylene (EPDM), EnDura™ (Steam Resistant), Silicone (VMQ), Fluorosilicone (FVMQ), ), Viton® A, Viton® B, Viton® GF, Viton® GLT, Viton® GFLT, Viton® ETP

Perfluoroelastomers (FFKM) including: Perlast™, Perlast Ice™, Simriz™, Gplast®, Kalrez®, Chemraz®, and others

Polyurethane (AU), Hydrogenated Nitrile (HNBR), Aflas® (FEPM), Polytetrafluoroethylene (PTFE), Neoprene (CR), Encapsulated (FEP/PFA) Styrene Butadiene (SBR), Anti Explosive Decompression Compounds (AED), Viton Extreme®, Metal Detectable, X-Ray Detectable, & many more.

D Ring shore hardness - range from 40 Shore to 90 Shore.

D Ring colours - A range of different colours available, which subject to minimum production quantities

D Ring installation - Coating to aid lubrication can also be supplied




WRC, WRAS, FDA, EC1935/2004 & EC2023/2006, USP Class VI, 3A Sanitary and many more


Selection Boxes, Splicing Kits & Top-up Bags are available

Bespoke D Ring Kits and selection Boxes are also available