37S-2 RATERMANN Cryogenics T (844) 341-3433 S F (844) 341-3444 S Website: www.rmicryo.com S Email: [email protected] LNG, LPG Butterfly Valve Cryogenic (LNG, LPG) Butterfly Valve Cryogenic Butterfly Valves Evolution cryogenic valves are widely used throughout the world, from liquefaction plants, to liquefied gas carries, receiving tank terminals as well as peak shaving plants, in critical and hazardous service conditions down to temperatures as low as -196°C. The materials used throughout are of austenitic stainless steel which maintains its strength at low temperature and the sealing system is a soft sealing, fire safe type incorporating Kel-F ring inserts into the disc which ensures trouble free operation. Metal seated movable double offset design is available. The valves are of extended bonnet design to create an insulation gas column between the packing and the cold fluid. The butt-weld end design has a side entry maintenance system to make the replacement of sealing ring without removing the valve from the pipe. Operators The following operation of the valve is available, the choice depending upon the valve location and the type of work and service for which the valve is used. • Manual Lever Operation • Manual Worm Gear Operation • Single or Double Acting Pneumatic Operation • Hydraulic Actuator Operation • Electric Actuator Materials Specification for Evolution Cryogenic Valves All materials supplied for the valve components are suitable for operation in LNG installations. Impact test is carried out on pressure retaining parts (body, bonnet, disc, studs and nuts) of cast material, according to ASTM Testing Procedures, with Charpy V Specimen, at -196˚C. Fire Safe Design The sealing system is designed to have a Kel-f seal ring inserted into the disc for sizes 2” and larger. This Kel-f seal ring is replaceable to enable easy maintenance. In addition, soft sealing by Kel-f seal performs an excellent and flexible sealing characteristic with minimum leakage on critical service conditions at temperature of -196˚C. In the event of a fire, even if the Kel-f seal ring is destroyed, the sealing system is secured by a secondary metal to metal sealing. Physical Properties of “Kel-F” High compressive strength and superior creeping resistance “Kel-f” (polychlorotrifluoroethylene: PCTFE) has high compressive strength and creeping resistance, and is superior to polytetrafluoroethylen: PTFE. Even under intense low temperature (liquefied H2: -255), “Kel-f” has superior elastic memory and tendency. Resistance against Low and High Temperature “Kel-f” is specified for temperature conditions from -200˚C to +200˚C. Water and Moisture Resistance “Kel-f” has superior characteristics of anti-moisture and complete water resistance, moisture absorption is nil. Even in water or high humidity conditions,”Kel-f” has perfect dimensional and elastic characteristics. Facilities against impact force and wear out “Kel-f” has superior facilities to resist impact force and wear out, and suitable for a long life service. Minimum Shrinkage Even at liquefied N2 temperature (-196˚C) condition, shrinkage and deformation are negligible. Conclusion “Kel-f” is the most suitable material for the seal rings of valves on a cryogenic service. No Part Name Material 1 Body Ductile Iron / Cast Steel / Stainless Steel 2 Disc Stainless Steel 3 Retainer Cast Steel / Stainless Steel 4 Seat PTFE, RTFE, PCTFE 5 Upper Stem Stainless Steel 6 Lower Stem Stainless Steel 7 Yoke Ductile Iron / Cast Steel / Stainless Steel 8 Bearing Stainless Steel 9 Bearing Stainless Steel 10 Gasket Non Asbestos 11 Bottom Cover Cast Steel 12 Stand Ductile Iron / Cast Steel / Stainless Steel 13 Packing Gland Stainless Steel 14 Packing PTFE, RTFE, PCTFE 15 Disc Pin Stainless Steel 16 Gear Box Assy
