Solutions

Valve Seats


Valve Seats

We manufacture a wide range of soft seat configurations across many industries supplying major global customers.

Applications

  • Valve seats and seat inserts - seats for all types of valves including ball valves, butterfly valves, gate valves, chokes and plug valves.
  • Valve stem seals - including chevron packing and all types of energised seals.
  • Complete valves, valve liners, and linings.

Materials

  • PTFE (Filled and Unfilled) provides a low friction seat, with excellent media compatibility.  Filled grades provide wear resistance and can support seating loads of the higher class of valves.
  • PEEK (filled and Unfilled) is a high modulus material providing higher temperature capability and compression resistance when compared to many other polymers.  Fillers can improve friction characteristics and reduce actuation torque.
  • Nylons are a rigid polymer that provides a low-cost solution in medium class valves.  Special blends provide low moisture absorption and low torque characteristics
  • Acetal is a rigid polymer which has low cold flow.  It provides good performance in the higher class valves.  Suitable for Nuclear applications.
  • PCTFE is a high modulus material that provides excellent resistance to dimensional instability due to low-temperature effects.  Therefore suited to cryogenic service conditions

Classes of Valves

Many ball and gate valves are rated by the pressure and temperature of service, commonly known as the valve class within the ANSI and ASTM classifications.  Polymer seats can achieve the sealing performance requirements throughout the range of classes from #150 thru #2500.  Typically the high modulus materials meet the requirement of the higher class valves.


 For the categorisation of valve operating characteristics (in particular operating torque) plastic valve seat materials can be grouped in three categories Stiff, Normal and Flexible.

  • "Stiff" materials include filled grades of high performance engineering plastics such as PEEK.
  • "Normal" plastic materials include virgin PEEK, polyamides and PCTFE.
  • "Flexible" materials are mainly PTFE (and its derivatives) both filled and unfilled.

Capabilities

  • We can develop many materials for specific valve applications.
  • Standard sizes ranging up to 1550mm (larger sizes available upon request)