Emergency shut-off valve for liquid ammonia/ammonia gas

Type: Pneumatic/Normally Closed Constant fast hydraulic/normally closed

Introduction:

Emergency Cut off Valves, also known as liquid ammonia emergency shut-off valves, are valves installed at the outlet of liquid ammonia storage tanks that can quickly cut off in case of emergency. They use gas sources (compressed air, nitrogen) and solenoid valves to control the opening and closing of the valves, and are widely used in the inlet and outlet of ammonia or weakly corrosive gas storage tanks and pipelines.

The internal structure of the liquid ammonia emergency shut-off valve is equipped with a low melting point (melting alloy) plug. In case of emergency or when the external temperature is ≥ 80C (melting alloy), it will melt and block the gas pipe. The valve will quickly release pressure and close to ensure the safety of the liquid ammonia storage tank system.

The emergency shut-off valve for liquid ammonia is composed of a multi spring pneumatic diaphragm actuator or a floating piston actuator and a regulating valve. It receives signals from the regulating instrument and controls the cutting, connection, or switching of fluids in the process pipeline. Used in conjunction with a remote gas source [nitrogen/anhydrous air], the valve is controlled to open and close by the gas source, so that in case of leakage or even fire on the pipeline or storage tank, the gas source can be quickly depressurized through an electromagnetic valve or manually. It has the characteristics of simple structure, sensitive response, and reliable action.

working principle:

1. The valve is in a normally closed state during daily operation, and the solenoid valve coil is in a power-off state, without consuming electrical energy.

When an accident occurs, the valve coil instantly loses power, the solenoid valve coil loses power and exhausts, triggering the valve to quickly close and enter a self-locking state. At this point, even if the power is removed, the valve remains in a self-locking state and will not automatically reopen.

3. Install a two position three-way solenoid valve at the inlet of the gas source, and control the valve switch using a remote electrical control console.

4. When the solenoid valve loses power and exhausts, the valve will automatically close

5. Manually control the solenoid valve (press the red clip) to exhaust, and the valve will automatically close

6. The gas supply will only be restored after the staff have dealt with the accident and manually reopened the valve.

7. Working environment temperature:- 15～60℃

Performance specifications:

Pressure rating: 2.5/4.0 Mpa

Cylinder working pressure: 0.3-0.6Mpa

Operating temperature:- 40~+80℃

Cylinder medium: nitrogen and anhydrous air

Media used: natural gas, liquefied gas, liquid ammonia, gas

Melting time: ± 70 ℃

Closing time: ≤ 5 seconds

Cylinder opening pressure; ≥ 0.3-0.6Mpa

Valve body material: cast steel, stainless steel. 304,316,316L

Spring: 50CrVA (spring steel)

Cylinder, piston: ductile iron

Sealing ring, O-ring: polytetrafluoroethylene, nitrile rubber

Application operating procedures;

A, The pressure standard for the emergency shut-off valve of liquid ammonia is 20k 4.0MPa. The daily working pressure of the oil cylinder shall not exceed 6.0MPa, but must be higher than 2.0 MPa to ensure the normal operation of the oil cylinder. The shut-off valve should be opened and closed frequently, as prolonged opening can damage the lifespan of the cylinder spring.