Vacuum Negative Pressure Safety Valve
I. Introduction:
The vacuum negative pressure safety valve is suitable for negative pressure systems with a temperature ≤200℃. When the negative pressure inside the container exceeds the allowable value, the valve automatically opens to draw in air; when the negative pressure inside the container reaches the allowable value, the valve automatically closes, thereby protecting equipment and systems. When installed in a normal non-negative pressure system, if the vent valve of the container and system is not opened and negative pressure is generated, this valve will automatically open. The safety valve plays a safety protection role in the system. When the system pressure exceeds the specified value, the safety valve opens, discharging part of the gas in the system into the atmosphere, so that the system pressure does not exceed the allowable value, thus ensuring that the system does not have an accident due to excessive pressure. The safety valve is also called a relief valve. There are several typical structural forms of safety valves. The piston-type safety valve has a flat piston core. The air source pressure acts on piston A. When the pressure exceeds the safety value determined by the spring force, piston A is pushed open, and part of the compressed air is discharged into the atmosphere from the valve port; when the air source pressure is lower than the safety value, the spring drives the piston to move downward, closing the valve port.
II. Materials of Main Parts:
NO. | Part Name | Material for YFA72W-P | Material for YFA72W-R |
1 | Valve Body | ZG1Cr18Ni9Ti | ZG1Cr18Ni12Mo2Ti |
2 | Valve Seat | 1Cr18Ni9Ti | ZG1Cr18Ni12Mo2Ti |
3 | Adjusting Ring | 1Cr18Ni9Ti | 1Cr18Ni12Mo2Ti |
4 | Valve Cover | ZG1Cr18Ni9Ti | 1Cr18Ni9Ti |
5 | Valve Stem | 1Cr18Ni9Ti | 1Cr18Ni12Mo2Ti |
6 | Spring | 50CrVA | 50CrVA coated with fluoroplastic |
III. Overall Dimensions and Connection Dimensions:
Nominal Diameter | Dimensions | ||||||
D | D1 | D2 | Z-?d | b | f1 | H | |
15 | 95 | 65 | 45 | 4-14 | 14 | 2 | 110 |
20 | 105 | 75 | 55 | 4-14 | 16 | 2 | 130 |
25 | 115 | 85 | 65 | 4-14 | 16 | 2 | 150 |
32 | 140 | 100 | 78 | 4-18 | 18 | 2 | 180 |
40 | 150 | 110 | 85 | 4-18 | 18 | 3 | 200 |
50 | 165 | 125 | 100 | 4-18 | 20 | 3 | 221 |
80 | 200 | 160 | 135 | 4-18 | 22 | 3 | 245 |
100 | 220 | 180 | 155 | 8-18 | 22 | 3 | 253 |
125 | 250 | 210 | 185 | 8-18 | 24 | 3 | 280 |
150 | 285 | 240 | 210 | 8-23 | 24 | 3 | 329 |
200 | 340 | 295 | 265 | 8-23 | 26 | 3 | 377 |
250 | 395 | 350 | 320 | 12-23 | 28 | 3 | 440 |
| Machinery & Equipment/Valves/Safety Valves | |
