Low Temperature Butterfly Valve is valve suitable for service that temperature -46 Degree C ~ -196 Degree C, these valves are generally used extended-stem or extended-bonnet design.
For using in cryogenic situation, the extended stem/bonnet design shall be applied. Extended stem/bonnet butterfly valve can be provided by ZFV according to customer requirement.
ZFV can provide extended butterfly valve with various size, pressure and material .
Basic Info. of our Low Temperature Butterfly Valve
* Pressure : PN16
* End Type: Full LUG ends
* Operation : Gear box with Manual Handwheel
* Torque : 3700/N.m
* F-F length : 102mm
* Design Structure : triple offset
* Seal type : stainless steel layer laminated with graphite
* Application : Chemical Industry application
* Need Extended Stem : Yes
* Suitable Temperature : -46°C ~ 200°C
* Suitale Pressure : not higher than 1.6Mpa
* Suitable service : W.O.G , low temperature service
* Provide Matching Flanges and bolts : Availale in need
* Function : Shutoff
* Material : body SS304L ( A351 CF3 ),
disc SS304L ( A351 CF3 ),
seal laminated SS316+graphite.
stem SS304L ( A182 F304L )
* Standard : Design API609
F-F dimension API609
Flanges dimension ASME B16.5
* Origin : Wenzhou , ZJ Provice, China
* EN 10204-3.1 certificate
* Third Part Inspection : Acceptable
1. The fluid resistance is small, and the sealing surface is less brushed and eroded by the medium.
2. The opening and closing of the Low Temperature Butterfly Valve is labor-saving.
3. The flow direction of the medium is not limited, no disturbance, no pressure reduction.
4. The valve has a simple shape, short structure length, good manufacturing process and wide application range.
The reasons to use used extended-stem or extended-bonnet design:
(1) The extended-stem has the function of protecting the stuffing box of the cryogenic valve, because the tightness of the stuffing box is one of the keys of the Low Temperature Butterfly Valve. If the packing box leaks, it will reduce the cooling effect and cause the liquefied gas to vaporize. As a result of media leakage, ice will be formed on the filler and the stem, affecting the normal operation of the stem and simultaneously moving the stem up and down. Filler scratches will cause serious leaks. Therefore, it is necessary to ensure that the temperature of the stuffing box is under 8 degree C.
(2) The extended-stem or extended-bonnet structure facilitates the jacketing material of gryogenic valve and prevents the loss of cold energy of cryogenic valves.
Low pressure seal shall be carried out according to one of the following methods:
--For bi-directional sealed valves (except multi-channel valves and globe valves), pressure should be applied at each end of the closed valve and opened to the atmosphere at the other end to check the leakage of the sealing surface at the outlet end. For unidirectional sealed valves marked with direction of medium flow, pressure shall be applied at the inlet end.
--For check valves, the clean water or soapy water should be poured into the sealing surface at the open end of the valve under pressure at the outlet end, and the bubbles should be observed to check the leakage of the seats and seats in contact with the valve body and the sealing pad of the valve. It can also be inspected according to the test device specified in the order contract, but it should be converted into the leakage unit specified instandard API 598.
--For multi-channel sealed valves, the test medium should be introduced into the pressure from the sealed port in turn, and the leakage rate of the sealing face of the inlet end should be checked from the packing box (at this time, no packing should be installed) or other open channel opening. During the test, the leakage rate of each sealing surface shall not exceed the leakage rate specified in standard API 598.
--For bi-directional sealed valves (except multi-channel valves and globe valves), pressure should be applied at each end of the closed valve and open to the atmosphere at the other end to check the leakage of the sealing surface at the outlet end. For unidirectional sealed valves marked with direction of medium flow, pressure shall be applied at the inlet end.
--Valve re-test: If the order contract does not stipulate that the buyer shall carry out the re-test, the valves that have been tested need not be re-tested. When re-testing, the painted valve does not need to remove the paint. Inventory valves should be cleaned before re-testing and shipment.