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
Screw To Connect CouplingsRK

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.

0°

106°C 223°F

Nitrile

120°C 248°F

EPDM

200°C 392°F

Viton®

300°C 572°F

Kalrez®

0°

-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)