The valve is connected to the pipe using pipe threads. ... Most valves employ the tapered thread type. The valve is welded directly to the pipe. This connection is usually used where perfect shutoff of leakage is crucial, Most common on urban water and sewerage and gas pipelines
Flanged connections are the most common method of connecting valves to piping systems regardless of pressure levels and valve size. They are made by using two flanges, which are attached using stud bolts and nuts. They are quick and easy to assemble and disassemble for repair or replacement purposes.
There are several processes of cleaning brass gas valve fittings. If you can disconnect your brass ball valve from the pipeline, take it to a sink and run water through at as high pressure as possible. If this does not clear the blockage in the brass valves and fittings, use a small brush (like a toothbrush) and dish soap to loosen and push out the blockage.
Spray the lubricant onto the valve where the valve handle enters the actual valve body and let it sit for about 20 minutes. Then, try loosening the valve by hand again. If it doesn't move, or is still difficult to turn, tap it lightly with the hammer.
1. Determine the type of valve: gate valve, globe valve, ball valve, butterfly valve, throttle valve, safety valve, pressure reducing valve, steam trap, etc.;
2. Determine the parameters of the valve: for automatic valves, according to different needs to determine the allowable flow resistance, discharge capacity, back pressure, etc., and then determine the nominal diameter of the pipeline and the diameter of the seat hole;
3. Determine the geometric parameters of the selected valve and fittings: the length of the structure, flange connection form and size, the size of the valve height direction after opening and closing, the size and number of connected bolt holes, the entire valve external dimensions, etc.
4. Determine the nominal diameter of the pipeline connected to the valve and the connection method, to understand which is flange, threaded, welded and other connections; know which way to operate the valve, manual, electric, electromagnetic, pneumatic or hydraulic, electrical linkage or electro-hydraulic linkage it.