D-Ring Seals

D-rings are an alternative for O-rings. A D-ring has the same sealing characteristics as an O-ring, but the flat base ensures better stability in the groove. This eliminates the risk of spiral failure, which occurs primarily during assembly and in dynamic applications.

Suitable for

  • Light dynamic applications.
  • Applications where the sealing solution is subjected to torsion during assembly/operation.

Not suitable for

  • High speed dynamic applications.
  • Applications where low closing force is required.

Advantages

  

  1. Stable sealing solution with high resistance to rolling in dynamic applications.
  2. High resistance to spiral failure.
  3. D-rings fit in existing O-ring grooves.

How do D-Rings work?

 

A D-ring is an elastic part placed between two parts and then squeezed to fill up the gap between the two parts. When the ring is pressurised, it’s forced to “flow” within the groove toward the clearance gap.

The D-ring has a flat surface to prevent twisting during movements. After installation, the ring is slightly compressed to seal at low pressures.

Technical Specifications

Movement type

Static, Light dynamic rotating/reciprocating

Available sizes

Any size available upon request.

Temperature range

NBR:      -40° to +108° C

EPDM:   -55° to +155° C

FKM:      -25° to +204° C

Hardness range

Static: 70 +/-5 Shore

Rotating: 90 Shore

Available materials

NBR, EPDM, FKM, CR, FVMQ, HNBR, FFKM, PU, VMQ

Available compliances

KTW, USP, NSF 51 61, WRC, WRAS, FDA, R67 01

Available standards

DIN11851

D-Ring Types

TYPE DP 

Type DP can be used in piston grooves for effective sealing in static to light dynamic applications.

Movement type:

  • Static
  • Light dynamic rotating/reciprocating

TYPE DR 

Type DR can be used in rod housing/grooves for effective sealing in static to light dynamic applications.

Movement type:

  • Static
  • Light dynamic rotating/reciprocating

TYPE DF 

Type DF can be used in flange/face grooves for effictive sealing in static applications

Movement type:

  • Static

Materials

 

Rubber Material  Characteristics Specifics Applications
NBR, XNBR, Nitril
Krynac®, Nipol®

Temperature range:-40° to +108° C
Chemical resistance:  •••••
Physical properties: ••••
Relative Cost••••

 
  • Excellent fuel resistance
  • Excellent oil resistance
  • High abrasion resistance
  • High resistance to heat aging
O-rings, Rubber Moulded Parts, light dynamic seals mineral based oil applications. Gaskets in oil and gas applications.
General purpose sealing solutions.
FKM, Fluorocarbon
Viton®, DAI-EL®, Dyneon®, Tecnoflon®

Temperature range:-25° to +204° C
Chemical resistance:••••
Physical properties:•••••
Relative Cost: ••••

  • High chemical stability
  • Low gas permeability
  • Excellent resistance in mineral oils
O-rings and light dynamic seals in fuel applications. General purposes sealing solutions where high chemical resistance is required.
FFKM, Perfluoroelastomer
Fluorezi®, Chemraz®, Isolast®, Parofluor®, Simriz®

Temperature range:-30° to +325° C

Chemical resistance:•••••
Physical properties:•••••
Relative Cost:•••••

  • Superior temperature resistance
  • Superior chemical properties
O-rings and rubber moulded parts where extreme temperature and chemical resistance is required, like chemical processing and high temperature fuel applications.
EPM, EPDM, Ethylenepropylene
Buna EP®, Keltan®, Nordel®, Vistalon®

Temperature range:-55° to +150° C
Chemical resistance:•••••
Physical properties:•••••
Relative Cost:••••

  • Excellent weather resistance
  • Good steam resistance
  • Compatible with brake fluids
Outdoor sealing applications. O-rings and Gaskets in drinking water applications.
VMQ, PVMQ, Silicone
KE®, Silastic®, Silplus®, Tufel®

Temperature range:-54° to +232° C
Chemical resistance:•••••
Physical properties:•••••
Relative Cost:•••••

  • Excellent weather resistance
  • Generally non toxic
  • Good fatigue resistance
  • High elongation
Heat exchanger Gaskets, Hollow O-rings for low pressure applications.
FVMQ, Fluorosilicone
FE®, Silastic LS®

Temperature range:-55° to +180° C
Chemical resistance:••••
Physical properties:•••••
Relative Cost:••••

  • Similar properties as VMQ with improved mineral and synthetic oil resistance
Diesel turbocharger and charge air cool hoses, exhaust hangers, wire and cable insulation.
FEPM, Tetrafluorethylene Propylene
Aflas®, Dyneon BRF®, Viton VTR®

Temperature range:20° to 204° C
Chemical resistance:••••
Physical properties:•••••
Relative Cost:••••

  • Excellent steam resistance
  • Superior resistance to strong bases
O-rings in cooling water applications. Sealing solutions in high temperature steam applications.
HNBR, Hydronated Nitrile
Therban®, Zetpol®

Temperature range:-30° to +150° C

Chemical resistance:•••••
Physical properties:••••
Relative Cost:••••

  • Similar properties as NBR with improved environmental resistance and chemical properties.
O-rings, hoses and membranes which require a high abrasion resistance.
PU, Polyurethane
Adiprene®, Estane®, Millathane®, Morthane®, Pellethane®, Texin®, Vibrathane®

Temperature range:-50° to +108° C

Chemical resistance:•••••
Physical properties:•••••
Relative Cost: ••••

 

  • Excellent extrusion resistance
  • High wear resistance
O-rings and shaft seals in high pressure applications. Sealing solutions in hydraulic cylinders and CO2 Firearms.

 

Alternatives for square rings

Lower closing force?

Hollow O-rings

Hollow O-rings are an alternative to D-rings, when low closing force is required.

Hollow O-rings ►

Better dynamic performance?

X-rings

X-rings, or Quad rings®, are an alternative for D‐rings. X-rings have four lips and therefore they have at least four sealing surfaces. The benefits are: high stability, space for lubricants between the sealing lips

X-rings ►

CONTACT FORM

    

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NewDealSeals

+31 (0) 226 362 233

info@newdealseals.com

Energiestraat 2-5, 1749 DN Warmenhuizen, The Netherlands