Eccentric Plug Valve Features and Benefits Analysis

Eccentric Plug Valve Features and Benefits Analysis

Welded Nickel Seats

The eccentric plug valve Seat is produced by machining a groove in the Cast Iron body, followed by welding a Nickel seating surface in the groove. After welding, the area is re-machined to provide a smooth, corrosion resistant surface for the plug to seat against. This seat is a minimum of 3mm thick after machining. In addition to the corrosion resistance of the nickel, the welding process creates a hardened zone that aids the seat s ability to resist abrasion.

Oil Impregnated Stainless Steel Bearings

The Eccentric Plug Valve has 300 series stainless steel bearings, making them highly corrosion resistant. The bearing is formed by pressing powdered stainless steel into the bearing shape, which is then impregnated with a lubricant, providing maximum lubricity.

P.T.F.E. Grit Seals.

To prevent grit and debris from damaging the bearing, the Eccentric Plug Valve has P.T.F.E. (Teflon) seals above and below the plug. These seals are held in compression between the plug body and bonnet, sealing the critical bearing area from the ingress of dirt and grit.

Self-Adjusting Stem Seals

Two self-adjusting, wear compensating, pressure energised ‘U’ cup seals are used to ensure a positive stem seal. An ‘O’ ring inside the ‘U’ cup provides the necessary pre-loading to guarantee sealing under low pressure, while the expansion of the ‘U’ cup at higher pressures prevents leakage. This packing is especially well suited to buried, submerged and hard to get to applications. In the unlikely event of stem seal failure these seals can be easily replaced without removing the bonnet from the valve.

Solid One-Piece Ductile Iron Plug

All Viking Johnson Eccentric Plug valves use solid, one-piece ductile iron plugs to ensure maximum flow capacity. Due to the higher strength of ductile iron (in comparison to cast iron) the thickness of the plug is reduced, resulting in a much larger flow way and greater flow capacity.

Multi-fit Bonnet

The bonnet of all Eccentric Plug Valves are drilled and tapped to accept a close-coupled gearbox or actuator and mounting kit. This can be accomplished on-site, even with the valve in service.

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