Cryogenic ball valve

SIZE: 2"~32" (ANSI 150 LBS~ANSI 2500 LBS)

1)Material: WCB, SS304, 304L, 316, 316L 
2)Shell wall thickness, ANSI B16.34 
3)Certificate: ISO9001: 2000 
4)Pressure-temp. Rating- ANSI B16.34 
5)End flanges: ANSI B16.5 
6)Butt welding ends-ANSI B16.25 
7)Suitable medium: Water, gas, air and some corrosive liquid 

Standard: 
> Standard compliance: API 6D, API-608 ANSI B 16.34, BS 5351 
> Face to Face: Dimensions: ANSI B16.10 
> Flange Dimensions: ANSI B16.5, MSS SP44 for 26" O 
> Pressure Rating: ANSI B16.34 

Materials: 
CF8M (SS316), CF8 (SS304) CF3M (SS316L), CF3 (SS304L), DIN 1.4408, SCS 14, WCB 1.0619 Available 

Feature: 
1. Investment Casting Body (2"~32") 
2. Trunnion Mounted Ball Designed 
3. Anti-Blow-Out stem 
4. Metal to Metal Seat (Option) 
5. Anti-Static Device 
6. Fire Safe Designed (Option) 
7. Test and Inspection: API 598 EN12266 

Operator: 
1. Lever 
2. Connection dimensions of Worm Gear actuator 
3. Electric, Pneumatic Actuator to ISO 5211 standard. 
4. Anti-static Electricity constructions 
5. Fire-safe constructions. 

Connection End: 
1. RF and RTJ flange ends to ANSI B16.5 or API 605. 
2. MSS SP-44 standard. 
3. BW flange ends to ANSI B16.25 standard.

Purpos

     Cryogenic ball valves are mainly used in the chemical equipment of ethylene and LNG etc ,to handle cryogenic liquid medium like ethylene .Liquid oxygen liquid hydrogen and so on .These types of inflammable and explosive medium can be volumetrically expanded by several hundred times when being gasified under temperature rise ,and are difficult to manufacture due to their highly penetrative and leaky properties .

Structure Characteristics    

     1.The materials of compression parts can endure the expansion and shrinkage resulted from the temperature variation of medium ,and seal structure is away from permanent deformation under temperature changes .To work under the conditions below -100 ℃ ,the parts of valve shall be subjected to sub-zero treatment before finish machining .Namely ,have the parts cooled in liquid nitrogen box ,when the temperature of parts reaches -196 ℃,keep the temperature for 1-2h,then them out to have them to the normal temperature naturally ,and do in this way twice .

     2. Bonnet is shaped long-necked for the purpose to protect the function of packing box ,making packing box somewhat away from low temperature to ensure good seal of packing .Besides ,it can be wound with cold insulating materials to prevent loss of cold energy .The length of neck depends on service temperature and the thickness of good insulating material .When the seal effect of packing turns lower ,fill in grease to form up oil seal layer in the middle of packing box to lower the differential pressure of packing box and enhance the dependability of seal .

     3.To serve a temperature below -100 ℃,the material of valve stem shall be treated with chromeplating or nitriding to enhance the surface hardness of valve stem and the dependability of packing .

     4.Cryogenic ball valve takes a structure to avoid abnormal pressure rise .As the medium in cryogenic valve is gasifiled and rapidly expanded in volume ,the pressure will good extremely high .When the pressure in the middle cavity of valve rises ,the middle cavity and the inlet side can be communicated ,or a relief can be mounted at the inlet side of valves ,thus to ensure the safe use of valves .