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

Product number	DQ41F-10C-100	DQ41F-10P-100P
	DQ47F-10C-100	DQ47F-10P-100P
valve body	LCB	CF8
spheroid	304	304
valve stem	304	304
sealing ring	PTFE	PTFE
packing	PTFE+O-ring	PTFE+O-ring
Applicable media	water, oil, steam, etc.	Corrosive media such as acid
Applicable temperature	-50-29℃	-196-29℃
Worm Gear Cryogenic Ball Valve	Insert “3” after DQ to indicate, example: DQ341F-16P
Pneumatic cryogenic ball valve	Insert “6” after DQ to indicate, example: DQ647F-16C
Electric cryogenic ball valve	Insert “9” after DQ to indicate, example: DQ941F-25P

 

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

Product number	Nominal diameter DN	PN1.6MPa								WT （kg）
		L	D	D1	D2	b	Z-Φd	H	W
DQ41F-16C DQ41F-16P DQ641F-16C DQ641F-16P DQ941F-16C DQ941F-16P	15	130	95	65	45	14	4-Φ14	178	140	3
	20	140	105	75	55	14	4-Φ14	184	160	4
	25	150	115	85	65	14	4-Φ14	195	180	5
	32	165	135	100	78	16	4-Φ18	280	250	9
	40	180	145	110	85	16	4-Φ18	280	300	11
	50	203	160	125	100	16	4-Φ18	300	350	15
	65	222	180	145	120	18	4-Φ18	330	350	19
	80	241	195	160	135	20	8-Φ18	360	400	27
	100	305	215	180	155	20	8-Φ18	400	500	38
	125	356	245	210	185	22	8-Φ18	430	600	58
	150	394	280	240	210	24	8-Φ23	500	800	81
	200	457	335	295	265	26	12-Φ23	680	800	95
	250	533	405	355	320	30	12-Φ25	790	1300	140

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

Product number	Nominal diameter DN	PN2.5MPa								WT （kg）
		L	D	D1	D2	b	Z-Φd	H	W
DQ41F-25 DQ41F-25P DQ641F-25 DQ641F-25P DQ941F-25 DQ941F-25P	15	140	95	65	45	16	4-Φ14	178	140	3
	20	152	105	75	55	16	4-Φ14	184	160	4
	25	165	115	85	65	16	4-Φ14	195	180	6
	32	178	135	100	78	18	4-Φ18	280	250	10
	40	190	145	110	85	18	4-Φ18	280	300	14
	50	216	160	125	100	20	4-Φ18	300	350	20
	65	241	180	145	120	22	8-Φ18	330	350	25
	80	283	195	160	135	22	8-Φ18	360	400	30
	100	305	230	190	160	24	8-Φ23	400	500	40
	125	381	270	220	188	28	8-Φ25	430	600	65
	150	403	300	250	218	30	8-Φ25	500	800	85
	200	502	360	310	278	34	12-Φ25	680	800	100
	250	568	425	370	332	36	12-Φ30	790	1300	165