Nitrogen sealing valve working principle and fault repair
Medical Device Motor Connectors Yihua Precision Machining Co, Ltd. , https://www.yhmachining.com
There are two forms of nitrogen seal in the tank are in normal operation, the two forms of nitrogen nitrogen source pressure are nitrogen nitrogen cylinder, nitrogen pressure is high, but the nitrogen pipeline is thin, there is no pressure reducing valve, and Direct access to self-nitrogen valve, self-nitrogen valve with automatic pressure regulating function, there is no need to set in the front of the pressure reducing valve, the nitrogen tank seal pressure is very low, we control the ± 500pa, for the storage tank protection One type is through the self-operated nitrogen seal valve installed on the top of the tank to close the nitrogen valve to control the nitrogen valve is also provided by the self-regulating valve manufacturers, nitrogen valve is the role of self-regulating valve Valve work to play a safety role, when the pressure is too high, such as when the tank pressure at +500 Pa, although the nitrogen valve to stop nitrogen, but when the tank continues to enter the material, the tank pressure rise, the storage The contents of the tank through the nitrogen valve to vent gas to maintain the gas pressure in the tank maintained at + 500pa, so that the tank does not overpressure, we do not set safety valve, but by the nitrogen valve control, When the tank pressure will be below -5 00pa, self-regulating valve into the nitrogen tank pressure will not be too low. There is also a form of self-regulating valve with a double seal of the respiratory groove supporting the tank pressure is also controlled ± 500pa, the basic working principle Ibid, when the pressure reaches +500 Pa, the gas inside the tank break through the respiratory groove of water Sealed, maintaining the pressure inside the tank does not exceed +500 Pa, when the pressure inside the tank is too low, on the one hand self-regulating valve action to supplement nitrogen to the tank to maintain nitrogen pressure is not too low, in case of self-regulation When the valve fails, another water seal in the breathing chamber plays a role. The outside air breaks through another water seal and enters the storage tank to keep the pressure of the storage tank low to -500 Pa, avoiding the disadvantages of the storage tank. No safety valve. The above form, that is to prevent the overpressure caused by the positive pressure of the storage tank, avoids the phenomenon that the negative pressure of the storage tank may bring about, and ensures the safety of the storage tank. Failure analysis and treatment (1) a large aromatic device drive early found 24 nitrogen sealing valve are not working properly. Check the demolition of the valve and found that the nitrogen valve air valve, the main valve and the two valve chamber wall and so stained with a thick layer of dirt, after wiping, grease can be used normally. At the valve seat also found some of the welding slag led to rust within the pipe after the drive, the residual debris and so on nitrogen blowing nitrogen into the valve, so that the main valve can not be returned to the valve seat. (2) Catheter blockage. If the pressure guiding tube is blocked, there is no feedback signal from the nitrogen sealing valve, which will cause the nitrogen to be constantly replenished to the tank. Follow the steps shown in Figure 3 to check whether this is the reason. (3) spring stretch smaller. If the pilot valve, the main valve and the two spool chamber is not dirty, and the pilot pressure pipe is not blocked, check the spring force of the small spring below the pilot valve, if the stretch is reduced, will make the nitrogen valve keep replenishing . The spring can be stretched to increase its elasticity. (4) seal damage. Pneumatic valve in the work process more frequently. So that the ring is often subject to the impact of the valve seat, resulting in wear or tear seals, can not play the role of sealing, sealing ring can be replaced. (5) control air inlet and air outlet outlet anti-installed. This is a product quality problem. Combined with the working principle of nitrogen valve, you can make judgments.