Safety valve
key word：Heat exchange element
Category:
Product description
Safety valve
1. Introduction
1.1. Purpose
Safety valve is used in power plant boiler or pressure vessel to prevent its pressure from exceeding the allowable value.
1.2. Structural features
1.2.1. The heavy hammer safety valve is a kind of valve that the heavy hammer exerts the heavy hammer force on the valve disc through the lever and stem to keep the valve sealed. The required take-off pressure can be achieved by adjusting the position of the heavy hammer on the lever.
1.2.2. Impulse safety valve and main safety valve are used together to form impulse safety device. When the medium pressure rises to the set pressure, the impulse safety valve opens, and the medium enters the piston chamber of the main safety valve from the exhaust pipe of the impulse safety valve. The piston is pushed down by the medium force to open the valve disc, so as to discharge the medium in the container. When the pressure is reduced to the allowable value, the impulse safety valve is closed, the pressure on the piston of the main safety valve is reduced, and the valve disc is closed by the medium pressure.
2. Main technical parameters (see table 45-1)
Table 45-1 main technical parameters of safety valve
| Item | Parameter |
| Nominal (working) pressure range（MPa） | PN4～PN10 |
| Operating temperature range（℃） | 427～540(800～1004℉) |
| Nominal size range (mm) | Impulse safety valve DN20 ~ DN25; main safety valve DN 100 ~ DN250 |
| Connection mode | Flange or welding |
| Valve body material | WCB, WCC, C12A, WC9, WC6, ZG20CrMoV, CF8, 25, SA105, 12Cr1Mo1V, F91, F22, F304, F316, F21 |
