RK Series

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Semi flat faced zero leakage screw connect couplings

Construction ApplicationsDemolition ApplicationsForestry ApplicationsTrailer Applications

Holmbury’s RK Series screw to connect couplings are designed for heavy-duty service conditions in applications including construction plant, high pressure pulse and agricultural machinery.
Connect Under Pressure TechConnect Under Pressure
Min Spill TechMin Spill
Carbon Steel Zinc Nickel Materials

Features

  • Screw to connect design eliminates brinelling
  • Allows for minimal inclusion of air and contaminants during connection
  • Flat face design prevents fluid loss during disconnection
  • Bidirectional flow
  • Can be connected with up to 50 bar (735 psi) residual pressure in the hydraulic circuit











Accessories

• Dust caps, plugs and seal kits are available for the RK Series

Construction

  • Carbon steel with zinc nickel plating (1200 hours with no red rust in salt spray tests)
  • Fitted with Nitrile seals











Applications

  • Hammer circuits
  • High pressure pulse applications
  • Construction plant
  • Mobile equipment
  • Demolition 
  • Agricultural industries











AVAILABLE SEALS AND TEMPERATURE RANGE

All carbon steel products have Nitrile Butadiene Rubber seals fitted as standard. All stainless steel products have Fluoro-elastomer Rubber (Viton®) seals fitted as standard. Special seal materials available on request.

106°C 223°F

Nitrile

120°C 248°F

EPDM

200°C 392°F

Viton®

300°C 572°F

Kalrez®

-20°C -4°F

Viton®

-25°C -13°F

Kalrez®

-40°C -40°F

Nitrile

-50°C -58°F

EPDM

Abbreviation Trade Name Chemical Name Min Temp. Max Temp.
NBR XNBR Chemigum®, Hycar8, Breon®, Butakon®, Butacril®, Buna-N®, Perbunan®, Paracril®, Krynac®, Europrene-N®, Nipol® Nitrile Butadiene Rubber Carboxylated Nitrile Rubber -40°C (-40°F) 106°C (223°F)
FKM (FPM) Dai-el®, Fluorel®, Tecnoflon®, Viton® Fluoro-elastomer Rubber -20°C (-4°F) 200°C (392°F)
EPR EPDM Buna-AP®, Dufral®, Epsyn®, Nordel®, Epcar8, Keltan®, Royalene®, Polysar-EPDM® Ethylene Propylene Copolymer Ethylene Propylene Terpolymer -50°C (-58°F) 120°C (248°F)
FVMQ Silastic 1S®, FSE® Fluorosilicone Rubber -65°C (-85°F) 170°C (338°F)
FFKM Perlast®, Kalrez®, Chemraz®, Kaflon® Perfluoroelastomer -25°C (-13°F) 300°C (572°F)