Valve after installation is completed, the operator can be familiar with the structure and properties of control valves and actuators, properly identify the direction of opening of the valve, opening signs, direction signals, skillful and accurate operation of the valve, timely and decisive handling of emergency failure. Valve operation is right or not, directly affect its service life, and related equipment and apparatus of smooth and safe production.
Precautions for operation
Prevent staggered valve leakage, fault clearance, opening and drain off. Operator must have a clear understanding of each valve function and location in the process pipeline, to prevent wrong operation, it may cause accidents such as running, mixing, hold pressure. If a refinery, steam blowing in the pre-construction, a vent valve leakage after blowing shut, as a result, when the work began in 370 ℃ high temperature slurry discharged from the vent valve, causing fires, the introduction unit shutdown.
Low temperature 0 ℃ the following season, to deactivate the valve, major frost, open end of valve plug, drain the condensate water inside. Cannot be ruled out and stopping valve warm-keeping measures to be taken.
Working on high temperature valves, when the temperature rises to more than 200 ℃, heat elongation of bolts, easy to make the valve seal is not strict, bolts should be as needed "hot tight", hot tight, should not be in the fully closed position of the valve. Avoid stem top dead, then open difficult.
Valve leakage, should identify the location and cause leakage, general internal leakage and leakage are two external leakage by its external structure divided into packing leakage and valve cover, valve leakage and leakage in sealing surface or lining material, operators shall accurately, they can be resolved in time and maintenance that cannot be resolved in time.
The valve packing gland should not be too tight, to stem a flexible rotation, pressure tight increases stem friction, increasing the operating torque. Valve when working under normal circumstances can't just replace or add packing under pressure, or cause a media leak is dangerous.