Globe valves are often overlooked in their work.
First, the cut-off valve injection grease, often ignore the problem of fat injection. After filling the grease, the operator chooses the valve and the grease-filling connection way, carries on the grease-filling operation. There are two kinds of situation: on the one hand, the amount of fat, low fat, sealing surface due to lack of lubricants and speed up wear and tear. On the other hand, excessive injection of fat, resulting in waste. is not according to the type of valve, the different cut-off valve sealing capacity for accurate calculation. Can be the cut-off valve size and type to calculate the sealing capacity, and then reasonable injection of the appropriate amount of grease.
Second, the cut-off valve grease, often ignore the pressure problem. In the fat-filling operation, the pressure of the injection of fat in the peak and valley changes regularly. Pressure is too low, seal leakage or failure, pressure is too high, grease mouth plug, sealed lipid hardening or seal ring and valve ball, valve plate embrace death. Usually when the injection pressure is too low, the grease injected into the valve cavity at the bottom, generally occurs in small valve. And the pressure is too high, on the one hand, check the grease mouth, if the fat hole obstruction, to identify the situation to replace; On the other hand, the lipid hardening, to use cleaning fluid, repeatedly soften the failure of the sealing grease, and inject new grease replacement. In addition, sealing model and sealing material, but also affect the pressure injection, different sealing forms have different injection pressure, the general situation of hard sealing grease pressure than soft seals. Ball valve maintenance Generally in the open position, under special circumstances, choose to close maintenance. Other valves can not be punished with open position. Gate valve in the maintenance must be in a closed state, to ensure that grease along the seal ring filled with sealed grooves, if the opening, sealing grease directly off the inflow path or valve cavity, resulting in waste.
After installation, the cut-off valve should be inspected regularly, the main inspection items:
(1) Globe valves sealing surface wear.
(2) Stem and stem nut trapezoidal thread wear.
(3) Whether the filler is obsolete, if there is damage should be replaced in a timely manner.
(4) After the cut-off valve overhaul assembly, the sealing performance test should be carried out.