First, the structural characteristics and uses
 1, through the flange for the square structure, the stem rod connection. 
 2, the valve body sealing surface using ball convex shape, and the valve to line seal. 
 3, the sealing surface with Babbitt, sealing performance, long service life.

Globe dark globe valves often use oxygen, nitrogen, hydrogen, argon and other gases. These gases are generally stored in a dedicated high-pressure gas. When using the ammonia through the cut-off valve to gas pressure drop to the desired range of experiments, and then through the other control valve fine-tuning, the gas input system. The most commonly used pressure reducing valve for the ammonia valve, referred to as ammonia valve. 

Second, performance specifications

Third, the main size and weight:

Fourth, the appearance and working principle
 Ammonia valve high pressure chamber and the cylinder connection, low pressure chamber for gas exports, and access to the use of the system. Indication of high pressure gauge is the pressure of gas stored in the cylinder. Low pressure gauge outlet pressure can be controlled by adjusting screw. 
 Open the cylinder main switch when using, then turn the low pressure gauge pressure adjusting screw clockwise to compress the main spring and drive the diaphragm, spring pad and ejector to open the valve. Such imports of high-pressure gas from the high-pressure chamber after throttling decompression into the low-pressure chamber, and through the exit leading to the working system. Turn the adjusting screw to change the opening height of the valve to regulate the passage of high-pressure gas and achieve the desired pressure value. 
 Ammonia cut-off valves are equipped with safety valves. It is to protect the ammonia valve and make it safe to use the device, but also the ammonia valve failure signal device. If due to the valve pad, valve damage or for other reasons, resulting in the pressure on the outlet and rise above a certain allowable value, the safety valve will automatically open the exhaust.

Fifth, the use of
 (1) according to the different requirements of use, ammonia valve has many specifications. Most of the highest import pressure, the minimum import pressure of not less than 2.5 times the outlet pressure. Export pressure specifications more generally, the maximum outlet pressure. 　　
 (2) Ammonia valve should be installed to determine whether the connection specifications consistent with the use of the system connector. Ammonia globe valve with hemispherical connection, by tightening the nut so that the two completely match. Therefore, the use of the two hemispherical surfaces should be kept clean to ensure a good airtight effect. Use high-pressure gas to blow off the dust before installation. If necessary, PTFE and other materials can also be used for gaskets. 
 (3) ammonia valve should be prohibited from contact with grease, so as to avoid fire accidents. 
 (4) stop working, the relief valve should be more than air net, and then loosen the adjustment screw to prevent long-term compression of the elastic deformation. 
 (5) Ammonia stop valve should be avoided impact vibration, not with corrosive substances in contact.