Globe dark globe valves-Shanghai ShangFa valve manufacturing (group) Co., LTD

First, the structural characteristics and uses
1, through the flange for the square structure, the stem rod connection.
2, the valve body sealing surface using ball convex shape, and the valve to line seal.
3, the sealing surface with Babbitt, sealing performance, long service life.

Globe dark globe valves often use oxygen, nitrogen, hydrogen, argon and other gases. These gases are generally stored in a dedicated high-pressure gas. When using the ammonia through the cut-off valve to gas pressure drop to the desired range of experiments, and then through the other control valve fine-tuning, the gas input system. The most commonly used pressure reducing valve for the ammonia valve, referred to as ammonia valve.

Second, performance specifications

Nominal pressure PN (MPA)	Test pressure PS (MPa)	Suitable media	Applicable temperature (℃)
2.5	3.8	Ammonia, ammonia and other NH3	Babbitt alloy -40 ℃ + 150 ℃	PTFE -40 ℃ +200 ℃
4.0	6.4

Third, the main size and weight:

DN (mm)	Size (mm)
DN (mm)	L	D	D1	D2	D4	b	f	f1	Z-φd	turn off	open	D3
10	130	90	60	40	35	16	2	4	4-φ14	165	185	110
15	130	95	65	45	40	16	2	4	4-φ14	165	185	110
20	150	105	75	55	51	18	2	4	4-φ14	170	200	120
25	160	115	85	65	58	18	2	4	4-φ14	197	210	120
32	180	135	100	78	66	20	2	4	4-φ18	199	213	140
40	200	145	110	85	76	20	3	4	4-φ18	248	264	160
50	230	160	125	100	88	22	3	4	4-φ18	265	295	180
65	290	180	145	120	110	24	3	4	8-φ18	310	349	220
80	310	195	160	135	121	26	3	4	8-φ18	340	357	240
100	350	230	190	160	150	30	3	4.5	8-φ23	380	413	280
125	400	270	220	188	176	32	3	4.5	8-φ25	430	451	320
150	480	300	250	218	204	32	3	4.5	8-φ25	505	492	360
200	600	360	310	278	260	34	3	4.5	12-φ25	550	806	400
250	650	425	370	335	31	36	3	4.5	12-φ30	730	880	450
300	750	485	430	390	364	40	3	4.5	16-φ30	-	995	550

Fourth, the appearance and working principle
Ammonia valve high pressure chamber and the cylinder connection, low pressure chamber for gas exports, and access to the use of the system. Indication of high pressure gauge is the pressure of gas stored in the cylinder. Low pressure gauge outlet pressure can be controlled by adjusting screw.
Open the cylinder main switch when using, then turn the low pressure gauge pressure adjusting screw clockwise to compress the main spring and drive the diaphragm, spring pad and ejector to open the valve. Such imports of high-pressure gas from the high-pressure chamber after throttling decompression into the low-pressure chamber, and through the exit leading to the working system. Turn the adjusting screw to change the opening height of the valve to regulate the passage of high-pressure gas and achieve the desired pressure value.
Ammonia cut-off valves are equipped with safety valves. It is to protect the ammonia valve and make it safe to use the device, but also the ammonia valve failure signal device. If due to the valve pad, valve damage or for other reasons, resulting in the pressure on the outlet and rise above a certain allowable value, the safety valve will automatically open the exhaust.

Fifth, the use of
(1) according to the different requirements of use, ammonia valve has many specifications. Most of the highest import pressure, the minimum import pressure of not less than 2.5 times the outlet pressure. Export pressure specifications more generally, the maximum outlet pressure. 　　
(2) Ammonia valve should be installed to determine whether the connection specifications consistent with the use of the system connector. Ammonia globe valve with hemispherical connection, by tightening the nut so that the two completely match. Therefore, the use of the two hemispherical surfaces should be kept clean to ensure a good airtight effect. Use high-pressure gas to blow off the dust before installation. If necessary, PTFE and other materials can also be used for gaskets.
(3) ammonia valve should be prohibited from contact with grease, so as to avoid fire accidents.
(4) stop working, the relief valve should be more than air net, and then loosen the adjustment screw to prevent long-term compression of the elastic deformation.
(5) Ammonia stop valve should be avoided impact vibration, not with corrosive substances in contact.

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