Triple Offset High Performance Butterfly Valve for LNG
The Westad butterfly valve for cryogenic service is designed for tight shut off and throttling service.
The disc movement is triple offset. This eliminates concentrated wear points on the sealing ring and extends it’s lifetime. Standard body patterns are flanged and butt welded types.
Butt welded type has extended body to prevent heat conduction to the sealing area during welding installation. An inspection door on top of the body enables easy inspection, maintenance and replacement of all inner parts and disc without the need to remove the valve or to cut the pipe.
To prevent internal stress in the bonnet during the cool- down period, all bonnet joints are bolted. This bonnet is extended to ensure that the gland area remains free from freezing even for temperatures down to -196 ̊C.
The valve can be installed with the shaft in any direction. The topflange drilling is according to ISO 5211 standards to fit a large range of gears and actuators.
|Temperature range:||-196°C to +200°C|
|Pressure range:||ANSI Class 150 / 300 / 600|
|Standard size range:||4" (DN100) - 48" (DN 1200)|
|Face to face dimensions:||
Butt welded type according to drawing
Butt welded type: Stainless Steel ASTM A351 CF3M
|Disc:||Stainless Steel ASTM A351 CF8M, stellited|
|Shaft:||Stainless Steel AISI 316|
|Nuts and bolts:||Stainless Steel AISI 316|
|Shaft seal:||Grafoil (graphite)|