The basic organization and maintenance of the valve
Role for the opening and closing of the valve, which is mainly made up of body, opening and closing member and the valve cover three parts. Seat on the valve stem of the valve opening and closing pieces do bring down movement, valves and valve seat of the clutch, the valve opening and closing.
Opening and closing mechanism consists valve (also called the valve plate, valve), stem and drives (hand wheel) components. Stem with trapezoidal thread screwed bonnet, hand wheel and valve fixed upper and lower ends of the stem and turn the handwheel, stem may rise or fall, to drive toward or away from valve seat to close and open, close the valve and valve seat match, by the pressure of the valve stem is pressed against the seat, when the valve is in the fully closed state, the valve does not leak tight.
Valve parts before assembly must go through the following process:
1, according to the processing requirements, some parts need to make polished surface can not have machining burrs, etc.;
2, all components degreased;
3, after the completion of degreasing pickling passivation, cleaning agents without phosphorus;
4, after purification pickling rinse with pure water, can not have drug residues, carbon steel parts omitted this step;
5, one by one with a non-woven dry parts, hair, etc. can not be wired retained part surface, or with a clean dry nitrogen;
6, with the non-woven fabric or sophisticated analytical filter paper moistened alcohol wipe parts individually, until there is no dirty color
The components must be clean sealed saved for installation. Specific requirements for the installation process is as follows:
1, the installation must ensure clean workshop, or build a temporary clean area, such as the purchase of a new color of the cloth or plastic film to prevent dust entering the installation process.
2, assembly workers must wear clean cotton overalls, wearing a cotton cap, hair can not leak, clean and wearing shoes, wearing plastic gloves, degreasing,.
3, the assembly tools must be used for degreasing and cleaning before assembly to ensure cleanliness.
For other requirements of the valve are:
1, the assembled valve purged with nitrogen for at least 1 minute.
2, air tightness test must be conducted with pure nitrogen.
3, air tightness test after passing the envelope, with a clean polyethylene cap sealed polyethylene cap soaked before use organic solvent, wipe clean.
4, and then vacuum sealed.
5, the final packing.
6, the transportation process to take measures to ensure entrapment is not damaged.
7, acceptance requirements: Acceptance follow HG 20202-2000 "skim construction and acceptance norms", are each part before assembly precision filter with a clean wipe, select parts dead, the same color as the paper qualification.