阀门知识入门.docx

Valves/chiefhelp/pipe_and_tubing/valves.htmGlobe??/chiefhelp/pipe_and_tubing/valves.htmGate??/chiefhelp/pipe_and_tubing/valves.htmButterfly??/chiefhelp/pipe_and_tubing/valves.htmCheck??/chiefhelp/pipe_and_tubing/valves.htmStop Check??/chiefhelp/pipe_and_tubing/valves.htmPressure Regulating??/chiefhelp/pipe_and_tubing/valves.htmControl Valves??/chiefhelp/pipe_and_tubing/valves.htmTraps and Strainers??/chiefhelp/pipe_and_tubing/valves.htmSteam Pressure Reducing Valve??/chiefhelp/pipe_and_tubing/valves.htmMaintenance ?and RepairEvery piping system must have some means of controlling the amount and direction of flow. This is accomplished with valves. Valves used in the machinery space piping systems, and constructed with threaded valve stems, must be right-hand closing (clockwise).Valves are usually made of bronze, brass, cast iron, malleable iron, or steel. Steel valves are either cast or forged, and are made of carbon steel, low alloy steel, or stainless steel. Alloy steel valves are used in high pressure, high temperature systems. The disks and seats of these valves are usually surfaced with a chromium-cobalt alloy known as STELLITE. This material is extremely hard.Bronze and brass valves are not used in high temperature systems or systems subject to high pressures, severe vibration and shock. Bronze valves are widely used in salt water systems. Seats and disks of bronze valves used for salt water service are often made of?Monel?An alloy of nickel and copper and other metals (such as iron and/or manganese and/or aluminum)?which is highly resistant to corrosion and erosion.Many different types of valves are used to control the flow of liquids and gases. There are two main groups of valves.STOP VALVES - Stop valves are used to shut off or, in some cases, partially shut off the flow of fluid. Stop valves are controlled by the movement of the valve stem. Stop valves can be divided into four general categories: globe, gate, butterfly, and ball valves. Plug valves and need