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Valves can be categorized into the following types, based on their operating mechanism: Ball valve, for on–off control without pressure drop. Ideal for quick shut-off, since a 90° turn completely shuts off, compared to multiple 360° turns for other manual valves; Butterfly valve, for on–off flow control in large diameter pipes
These valves often provide a simple on-off function. 3-way valves can be normally closed, normally open, and offer a universal function where gas can be diverted through a third opening to move the valve into the normally closed or normally open position. [1] [2] 3-way valves pressurize and exhaust one outlet port to control a single-acting ...
However, some large valves are impossible to operate manually and some valves may be located in remote, toxic, or hostile environments that prevent manual operations in some conditions. As a safety feature, certain types of situations may require quicker operation than manual actuators can provide to close the valve.
The normally closed valves will not permit flow from the inlet port of the valve to the outlet port, normally the flow will be permitted only by changing the position of the valve. In general, valves are designated as 2/2 DCV, 3/2 DCV, 5/2 DCV, 5/3 DCV etc., in which the first number indicates number of ports and second number indicates number ...
Pneumatic valve: Actuated using a compressible medium like air, hydrocarbon, or nitrogen, with a spring diaphragm, piston cylinder or piston-spring type actuator; Hydraulic valve: Actuated by a non-compressible medium such as water or oil; Electric valve: Actuated by an electric motor; A wide variety of valve types and control operation exist.
For example, a popular 3 ⁄ 4-inch 150 psi sprinkler valve, intended for 24 VAC (50–60 Hz) residential systems, has a momentary inrush of 7.2 VA, and a holding power requirement of 4.6 VA. [5] Comparatively, an industrial 1 ⁄ 2 -inch 10,000 psi valve, intended for 12, 24, or 120 VAC systems in high-pressure fluid and cryogenic applications ...
A typical nominal regulated gauge pressure from a medical oxygen regulator is 3.4 bars (50 psi), for an absolute pressure of approximately 4.4 bar and a pressure ratio of about 4.4 without back pressure, so they will have choked flow in the metering orifices for a downstream (outlet) pressure of up to about 2.3 bar absolute.
1. input airflow; 2. output airflow; 3. valve tubing; 4. valve casing; 5. internal rotor; 6. valve ports, or "knuckles"; 7. rotor spindle. A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. [1]