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Foster Products

ZSi Products


FF Plus Series, Flat Face
Sizes and Pricing

FF Plus Plug, Female Thread
Sizes and Pricing

FF Plus Socket, Female Thread
Sizes and Pricing

FF Plus Plug, Female Thread
Connect Under Pressure
Sizes and Pricing

FF Plus Dust Cap, for Plug
Sizes and Pricing

FF Plus Dust Cap, for Socket

The FF Plus Series couplers are a two-way shut-off hydraulic coupler. Typical applications for the steel series include:

  • Mobile Hydraulic Equipment
  • Agricultural Machinery Mining Equipment
  • Nuclear
  • General Industrial
  • Construction Equipment
  • Hammer Circuits
  • High Pressure Pulse Applications
  • Mobile Equipment
In addition to the applications for steel series, 316 stainless series are also used for:
  • Chemical Processing
  • Oil & Gas
  • Pharmaceutical Processing Equipment
  • Corrosive Fluid Environments
  • Marine Environments

Refer to the product flyer for more information...



  • (Sizes 06 to 25) - Carbon steel with zinc nickel plating fitted with Nitrile seals (Viton seals available)
  • 1200 hours with no white or red rust in salt spray tests
  • AISI 316 stainless steel fitted with Viton seals (Other seals available on request)


  • Safety locking sleeve to prevent accidental disconnection
  • Flat face design prevents fluid loss during disconnection and is easily wiped clean
  • Minimal inclusion of air and contaminants during connection
  • Bidirectional flow

Connect Under Pressure Plugs:

  • Connects under pressure by hand, with up to 350 bar locked in the male half.
  • The ideal choice for applications where the ability to connect under pressure is essential.


  • Dust Caps and Plugs


  • Couplers have been tested to the ISO 7241-2 Standard
  • Operating temperatures - Carbon Steel:
    • (With Nitrile seals): -40°C (-40°F) to 106°C (223°F)
    • (With Viton seals): -20°C (-4°F) to 200°C (392°F)
  • Operating temperatures - Stainless Steel:
    • (With Viton seals): -20°C (-4°F) to 200°C (392°F)