Applications
A Non-Firesafe and Firesafe High Performance Butterfly Valve. Double Offset Design Sizes 3" – 48". ANSI 150 and 300 lbs rating.

Design
The shaft is of one piece construction with an anti blow out feature on the non drive side and a reduced diameter at the actuator end. If failure of the shaft -to- disc connection, or internal failure of the shaft occurs due to excessive torque, no portion of the shaft can be ejected from the valve as result of internal pressure. This single piece construction also provides a rigid assembly when pinned to the disc via means of shaft pins (peened over and locked). This prevents excessive disc deflections, which maintains a constant disc/insert contact stress ensuring a bi-directional sealing valve at both low and high pressures. The valve has a double offset design providing a camming action. This eliminates excessive wear between the seat and disc-sealing interface both during the opening and closing strokes extending the sealing life of the valve. Maintenance of the valve is quick and relatively simple. The PTFE insert, seat gasket and secondary seat can be replaced by simply unbolting the retaining ring and assembling the new parts without removing any other parts. Gland packing is simply adjusted by tightening gland nuts, which are easily accessible between the mounting legs without having to remove the adapter plate or actuator.

Key Features

Certification Certified firesafe to BS 6755 part 2. Operation Tight shut off in both directions to API 598 Maintenance Field replaceable PTFE insert and secondry metal seat. Pressure Ratings ANSI 150#, 300#. PN 10, PN 16, PN 25. Others on request. Geometry Double offset giving low unseating and seating torques electroless nickel plated spherical blade periphery Body Designs Double flanged, wafer lugged, wafer flangeless. Flange Designs ANSI, API, MSS, BS, PN, ISO, DIN. Actuation Manual gearbox. Pneumatic, Electric, Hydraulic. Body Materials Standard, carbon steel (ASTM A216 WCB). Alternative Body Materials Monel 400, Zeron 100, Duplex stainless steels, Titanium, Avesta 254 6 MO, Inconel, Hastelloy Anti Blow-Out API 609 cat B Soft Seated Version The P.T.F.E. insert is rigidly held in the body and 'energised' onto the spherically machined disc by means of the secondary seat which is fixed into the body by a bolted in retaining ring. This version is used in low temperature and ambient applications. Firesafe Version The P.T.F.E. insert is rigidly held in the body and 'energised' onto the spherically machined disc by means of the secondary seat which extends onto the disc periphery and fixed into the body by a bolted in retaining seat. When the P.T.F.E. insert is burnt away, during a fire, the secondary metal seat is designed to 'energise' onto the disc and form a seal in both directions. Technical Description SOLENT & PRATT, T series valves are of Double Offset geometry design. This provides a camming action eliminating excessive wear between the seat and disc sealing interface both during the opening and closing strokes, extending the sealing life of the valve. The shaft is of one piece construction with an anti blow-out feature external to the pressure boundary on the drive side conforming to API 609. No portion of the shaft can be ejected from the valve as a result of internal pressure. This single piece construction also provides a rigid assembly which prevents excessive disc deflections, maintaining a constant disc / seal contact ensuring bi-directional sealing at both low and high pressures. For ambient and low temperature applications the PTFE seal is rigidly held in the body and 'energised' on to the disc by the secondary seat (seat energiser). For firesafe applications the secondary seat (seat energiser) extends on to the disc periphery. In a fire situation, when the PTFE is burnt away, the secondary metal seat is designed to 'energise' on to the disc and form a metal to metal seal in both directions. The PTFE seal can be quickly and easily replaced in the field. No special tools are required. Available in pressure ratings 150# and 300#. Lloyds certified firesafe to BS 6755 part 2.

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