DQ41F Cryogenic Ball Valve

1. Introduction to the use of DQ41F Cryogenic ball valve

1. Cryogenic ball valve refers to the valve whose medium temperature is -40℃~-196℃. Common Cryogenic valves are divided into Cryogenic butterfly valve, Cryogenic gate valve, Cryogenic ball valve, Cryogenic globe valve, Cryogenic check valve, Cryogenic throttle valve, etc. DQ41F cryogenic ball valve is suitable for the management system of cryogenic liquid storage and transportation equipment. The output liquid low-temperature medium, such as ethylene, liquid oxygen, liquid hydrogen, liquefied natural gas, liquefied petroleum products, etc., is not only flammable and explosive, but also needs to be gasified when heated up, and its volume expands hundreds of times when gasified.

2. The material of the LNG valve is very important. Unqualified material will cause external leakage or internal leakage of the casing and sealing surface; the comprehensive mechanical properties, strength and rigidity of the parts cannot meet the requirements of use or even break. Leakage of liquefied natural gas medium causes explosion. Therefore, in the process of developing, designing and developing LNG valves, the material is the primary and key issue.

Second, the DQ41F Cryogenic ball valve structure standard

1. Design: API6D, JB/T7749

2. Valve routine inspection and test: according to API598 standard.

3. Valve Cryogenic inspection and test: according to JB/T7749.

4. Drive mode: manual, bevel gear drive and electric drive.

5. Valve seat form: The valve seat adopts welded structure, and the sealing surface is surfacing with cobalt-based hard alloy to ensure the sealing performance of the valve.

6. The gate adopts an elastic structure, and a pressure relief hole is designed at the pressure inlet end.

7. The valve body with one-way seal is marked with the flow direction mark.

8. Cryogenic ball valve, gate valve, globe valve, butterfly valve adopt long neck structure to protect packing.

9. Ultra-Cryogenic ball valve standard: JB/T8861-2004.

3. Material selection of DQ41F Cryogenic ball valve

1. Valve body and bonnet adopt: LCB(-46℃), LC3(-101℃), CF8(304)(-196℃).

2. Gate: stainless steel surfacing with cobalt-based cemented carbide.

3. Seat: Stainless steel surfacing with cobalt-based cemented carbide.

4. Stem: 0Cr18Ni9.

Fourth, the Cryogenic valve test and inspection

The main parts of the low-temperature valve are treated at Cryogenic, and each batch is sampled for a Cryogenic impact test to ensure that the valve is not brittle under low-temperature working conditions and can withstand the impact of low-temperature media.

The following tests are performed on each valve:

1. Normal temperature shell strength test;

2. Normal temperature and low pressure upper sealing test;

3. Normal temperature and low pressure sealing test;

4. Cryogenic upper sealing air tightness test (when there is upper sealing);

5. Low-temperature gas sealing test, etc., to ensure that the entire low-temperature valve meets the requirements of the standard;

6. Perform Cryogenic treatment on main parts and perform Cryogenic impact test on each batch of samples to ensure that the valve is not brittle under Cryogenic conditions and can withstand the impact of Cryogenic media;

7. Cryogenic (cryogenic) valves are subjected to Cryogenic treatment and impact test according to the corresponding material specifications;

8. The electrostatic function is more powerful, and the conduction resistance between the valve body and the valve stem or the internal parts and the valve body is less than 1 ohm.

5. Main model parameters of DQ41F cryogenic ball valve

6. Main connection size parameters of Cryogenic ball valve 1.6Mpa

Fourth, the main connection size parameters of the Cryogenic ball valve 2.5Mpa