Product Description
2 Way Butterfly Valve
There is no media contact with the body. A completely leak proof stem seal however is offered with Butterfly Valves by the three sealing points illustrated.
- Primary Seal: Close fit between machined flat face of disc and large raised area of seat ring ensures perfect seal.
- Secondary Seal: 'O' ring between stem and body eliminates ingress of dust and dirt.
- Tertiary Seal: 'O' ring between stew and seat ring. A stainless steel 'O' ring housing is moulded in the seat ring to ensure a perfect stem seal.
Butterfly valves therefore can be used on vacuum service.Concentric Disc Design.
- Developed for water services up to 10 Kgf/cm (150 psi.)
- Handles flow in either direction.
- Body fully protected from corrosion by liner.
- Low pressure drop (good Cv characteristics).
- Streamlined concentric disc minimizes turbulence and erosion.
- Self Cleaning seat area.
- May be installed with shaft horizontal or vertical.
- Greater thickness of liner at seating area offers longer service life.
- Flange gaskets not required.
Eccentric Disc Design
- Developed for oil cargo services up to 16 Kgf/cm (240 psi).
- Accepts flow in one direction only.
- Not usually fully lined.
- Higher pressure drop especially in sizes under 150 mm.
- Eccentric Disc generates more turbulence and erosion.
- Seating areas not self cleaning.
- Should be installed with shaft horizontal.
- Smaller higher stressed seating area prone to give shorter service life.
- Flange gaskets required. No control over bolt pressure on gaskets.
