Main Safety Valve
manufacturer: Shanghai MeiYan Yi Pump & Valve Co., Ltd.
Eml: sales@1bengfa.com
Tel: +86 (21) 5640 2009
Mob: +86 138 1691 3072（WeChat Same Account）
product drawing
A49H-40 main safety valves
Applications and structure description
A49H type main safety valve is mainly used for power station boilers, pressure vessels, reducing temperature and pressure devices, to prevent the pressure exceeding the allowed maximum pressure value and ensure the safe operation of equipments. The main structural features of A49H high temperature and pressure safety valve are: 1, when the medium pressure rise to the setting pressure, the impulse valve opens, medium enters into the A49H-type main safety valve piston room from the pulse pipe, pushs the piston down, so that the valve opens automatically, when the impulse valve is closed, the disc shuts down automatically. 2, sealing surface is made of Co-based Cr-Ni stainless steel bead welding, after heat treatment, the disc improves wear resistance and anti-erosion.
Dimensions & constructral diagram
A49H-40 main safety valve constructral diagram
Main external and connection dimensions
| Type | nominal diameter DN（mm） | Connecting dimensions | ||||||||||||||
| L | L1 | L2 | H | D | D1 | D2 | b | Z-d | DN’ | D’ | D1’ | D2’ | b’ | Z-d’ | ||
| A49H-40 | 150 | 220 | 230 | 240 | 486 | 300 | 250 | 204 | 30 | 8-25 | 200 | 360 | 310 | 278 | 34 | 12-25 |
| A49H-40 | 200 | 270 | 295 | 330 | 615 | 375 | 320 | 260 | 38 | 12-30 | 300 | 485 | 430 | 390 | 40 | 16-30 |
| A49H-40 | 250 | 300 | 350 | 370 | 646 | 445 | 385 | 313 | 42 | 12-34 | 350 | 550 | 490 | 450 | 44 | 16-34 |
Installation instructions
1. the main safety valve must be installed perpendicular to the highest position of the device.
2. the main safety valve should be fastened to the support, the support bears the counterforce produced by main safety valve exhaust.
3. exhaust pipe should have special cradle, exhaust pipe weight shall not be added to the main safety valve, the connecting flange between the main safety valve and the exhaust pipe should eliminate any additional prestressing.
4. the lowest point of exhaust pipe should be considered drainage, to avoid producing water hammer when exhausting steam.
