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Resilient Seated Bypass Valves


Derwent Resilient Seated Bypass Valves, made in conjunction with AFC, are manufactured to AS/NZS 2638.2. The Gate Valves are applicable for water and waste water applications. Valves are available in both Anticlockwise and Clockwise configuration. Valves are supplied with Key Cap as standard, with ISO mounting plate for fitting handwheel, gearbox or actuator.

Features & Configurations:

  • Material: Ductile Iron Body and Bonnet to AS 1831

  • Wedge:  Ductile Iron AS 1831, fully encapsulated
    (Vulcanized) EPDM
    Rubber to AS1646 and AS681.1.
    The wedge is designed with abrasion resistant nylon
    which reduce the required opening 
    and closing torque through smooth operation


  • Stem:  431 Stainless Steel to ASTM A276,
    providing excellent
    corrosion and strength,
    reducing moving parts

  • Bolts:  316 Stainless Steel to ASTM A276, hot melt
    for superior corrosion resistance in
    harsh environments


  • Coating: Fusion Bonded Epoxy coated to  AS/NZS 4158
    provides the valve
    excellent corrosion protection


The Derwent Bypass Valves are for use in Potable Water, Waste Water, Fire, Irrigation, Water Circulation and Heating and Cooling applications and are suitable for both above and below ground installation.

Technical Information:

Size range:

  • DN 375 with 100mm Bypass

  • DN 450 with 100mm Bypass

  • DN 500 with 100mm Bypass

  • DN 600 with 150mm Bypass

Allowable Operating Pressure: 

  • 1600 kPa; 1.6 Mpa

Maximum Test Pressure (Shell):  

  • 2400 kPa, 2.4 Mpa

Maximum Temperature:  40 Deg C

End Connection:   

  • Flanged to AS 4087

      (Table E drilling also available)

Certification:    SAI Global  (see certificate for approved sizes)

WSAA Appraisal No.   PA1511
Watermark Lic. No.    25890 Standards Mark Lic. No. 25890

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