Which way to twist the plumbing switch is on, which way to twist is off left or right

Generally, clockwise is off, counterclockwise is on.

Except for special requirements, the valve is clockwise is off, counterclockwise is on, whether it is a faucet or a water valve, round or with a handle, in addition to double-open are, most of them are so.

Clockwise off the valve is designed to be more smooth, usually right twist the switch, so that the valve is closed.

Extended information:

Valves used in fluid control systems range from the simplest globe valves to a wide variety of valves used in extremely complex automated control systems, and their varieties and specifications are quite diverse. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metals and radioactive media.

Valves according to the material is 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, duplex steel valves, plastic valves, non-standard customized valve materials.