A wide selection of materials are available ranging from carbon steels, stainless steels (including duplex, superduplex and superaustenitic), Ni alloys (up to Inconel 625 and incoloy 825) and other advanced materials. Split body valves are generally made from forged or centrifugal casting, whereas top entry valves are generally manufactured from cast material. All the materials are supplied from approved sources and the characteristics of all the materials may be supplied as per specific requirements.
Valpres valves can be supplied with a manual lever/ gearbox or with any type of actuator. All valves are tested as a package prior to delivery. We can also supply the complete valve and actuator package including pneumatic or electric actuators.
-196°C (-320°F) to +350°C (+675°F).
Others available upon request.
Trunnion Mounted Balls
Permitting ease of operation, minimizing the torque and reducing seat seal wear.
Double O-rings, or the combination of O-rings and gaskets, enable a perfect and safe sealing of all body
Antiblowout stem allows the replacement of the stem seals with the valve in the fully closed position. The
stem seal integrity is achieved by the use of three O-rings. The upper seal can be replaced with the valve in
line and under pressure. Stem and ball are separate components; this ensures a better alignment and lower
torque. Stem and trunnion are supported by P.T.F.E. impregnated steel bearing sleeves. Emergency stem
sealant injection feature is standard on valves 4” and above.
Independent floating spring loaded seats are always in contact with the ball to provide an effective tight
seal even at low differential pressures. Independent upstream and downstream seats permit draining of
fluid from the body cavity, allowing double block and bleed operation. With the standard single piston seats feature, there is an automatic body cavity release of over pressure to the line through the down stream seat.
Double piston seat (that maintains the sealing capacity of the valve even in the case of failure of the up
stream seats) or a combination of double sealing features on the downstream side/single sealing on the
upstream seat is available on request. A seat emergency sealant injection system is available on request
which can restore the sealing integrity if damage occurs to the sealing surfaces.
Ball valves to be used in low temperature/cryogenic service are equipped with extended bonnet to allow
vapour space between body cavity and gland seals. This feature preserves stem seals from damage that
may occur during operation at cryogenic temperatures, and allows stem seal servicing even on valves
installed on insulated lines. Vapour space length or insulating thickness shall be specified. Valpres standards are:
BS 6364 and ISO 28921. Ball valves to be used in high temperature service are equipped with extended bonnet to allow the valves to be insulated and allow the top of the valve to exchange the heat, reduce the risk of burns and protect the operating systems from high temperatures.