Valves not suitable for use in ammonia refrigeration systems are ( )

It is a high-quality specialty valve used in refrigeration systems. Single-stage compression is different from two-stage compression. Especially ammonia engines.

The selection of installation valves for ammonia refrigeration systems should be determined in accordance with the requirements of the design documents or the operating conditions (operating pressure, operating temperature, etc.). Requirements for valves in ammonia systems; all types of valves used in ammonia systems (such as globe valves, throttle valves, check valves, solenoid valves, safety valves, etc.) must be designed specifically for use with ammonia, and they need to have properties such as pressure resistance and corrosion resistance. The nominal pressure of valves and fittings for ammonia should be no less than 2.5 MPa. The material of the valve body can be malleable cast iron or cast steel; since ammonia is corrosive to copper, no components made of copper or copper alloys are allowed in valves used in ammonia systems. All valves in the ammonia system should also be equipped with reverse-closing seat assemblies, so that in the event of a leak in the valve packing, it is possible to fully open the valve while the system is operating and under certain pressure, thereby allowing for the replacement of the packing. Each user unit shall purchase valves and pipeline components manufactured by units that possess the qualification for manufacturing pressure pipeline components. For gray cast iron valves used in liquid ammonia medium pipelines (including those using refrigerant ammonia), the applicable nominal pressure shall not exceed 1.0 MPa, and the operating temperature shall not be lower than -10°C.

There is now an integrally stamped valve made of seamless steel tube, designed specifically for use in refrigeration systems.

Low-temperature resistant LCB alloy steel valves or stainless steel valves should be used; ordinary WCB valves are not suitable.

For ammonia systems, valves specifically designed for ammonia must be used; the handwheels of such valves should be marked in yellow. Valves with copper seals are not permitted.

The thermometer is good; take a look. . . . . . . . . .

Hello, you mentioned above that \"the nominal pressure of valves and accessories for ammonia should not be less than 2.5 MPa.\" Could you please explain why this is the case? For the refrigeration system in our facility, the maximum pressure is around 1.5 MPa, and the setting pressure of the safety valve is also 1.6 MPa. Do the other valves need to be specified with a nominal pressure of 2.5 MPa or higher?