Specification The device shall consist of a pressure differential relief valve located in a zone between two positive seating, centre guided, encapsulated spring type check valves. If external sensing lines are utilised, they shall be flexible and constructed so as not to be subjected to crimping, pinching, or collapse. All units, no matter what nominal size, must be maintainable in line and have field replaceable seats, seals and spring assemblies. All seat/seal assemblies must be secured by stainless steel bolts or screws for ease of maintenance. All test cocks shall be positioned on top of the valve for ease of access and testing. Sizes DN15 - DN50 will be Gunmetal, DN65 - DN80 will be Fusion Bonded Epoxy Coated Cast Iron. - WATTS/RMC™ 009 OR EQUIVALENT |