Piston Valve

Description

Benefits

• Slow Opening– This helps to stop water hammer. The valve has a cage unit fitted in which the piston moves, creating a variable orifice by degree as opposed to simply ‘open or closed’. Therefore, perfect for steam.
• Tight Shut Off – The valve has a reliable seal between the piston and seal. The BSI classification is IV (0.01% of rated capacity)
• Can Be Maintained In-line – The replacement of the piston rings can be carried out in-line by removing the yoke, leaving the body seals and cage in-line. The top seal is removed, the cage unit taken out, the bottom seal removed and new seats simply installed in reverse order.
• No Leaks To The Atmosphere – Because the top ring has the same leakage classification as the bottom ring the chances of leakage are as good as or better than bellows-sealed valves.
• No Wiredrawing On Seating Face – The valve seals on the sides of the piston and not on the flat face. This means that if the valve is left in an ‘in-between’ position for any length of time, no wire drawing can occur on the seating face.
• DIN 2533 – The valve’s ‘face to face’ complies with DIN standards and can fit any comparable DIN valve.
• Not Affected By Flow Direction – The valve can therefore be used under or over the piston. However, we generally advise that the flow be used under the piston to assist with opening.

Specifications