What are the common valve classifications?
Classification by function and use:
(1) stop valve: stop valve is also known as closed valve, its role is to connect or cut off the medium in the pipeline. Cut-off valves include gate valves, globe valves, plug valves, ball valves, butterfly valves and diaphragm valves.
(2) check valve: check valve, also known as check valve or check valve, its role is to prevent the medium in the pipeline flow back. Water pump suction off the bottom valve also belongs to the check valve.
Valves can be used to control the flow of air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media and other types of fluids. Valves are also divided into cast iron valves, cast steel valves, stainless steel valves (201, 304, 316, etc.), chromium-molybdenum steel valves, chromium-molybdenum vanadium steel valves, dual-phase steel valves, plastic valves, non-standard valves, etc.
By function and use:
This kind of valve is open and close action. It is usually used in cold and heat source inlet and outlet, equipment inlet and outlet, pipeline branch line (including riser), and can also be used as water valve and air valve. Common shutoff valves are gate valves, globe valves, ball valves and butterfly valves.
Gate valves can be divided into open stem and dark stem, single and double gate, wedge and parallel gate, etc. Gate valve closing tightness is not good, large diameter gate valve is difficult to open; The valve body size along the flow direction, flow resistance is small, gate valve nominal diameter span is large.
Cut-off valve according to the flow direction of the medium is divided into straight-through type, right-angle type and straight flow three, there are bright rod and dark rod points. The closing tightness of the globe valve is better than the gate valve, the valve body is long, the flow resistance is large, the maximum nominal diameter is DN200.
