- Settore: Industrial valves
- Number of terms: 3113
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A special type of regulator that is installed between the valve positioner and the valve actuator, where it senses the supply air pressure. If that pressure falls below a certain level, it locks or traps the air loaded into the actuator causing the valve to fail-in-place.
Industry:Industrial valves
A special trim used in control valves to stage the pressure drop through the valve, which will either prevent the cavitation from occurring or direct the bubbles that are formed to the center of the flow stream away from the valve body and trim. This is usually accomplished by causing the fluid to travel along a torturous path or through successively smaller orifices or a combination of both.
Industry:Industrial valves
A sealing system that normally consists of a deformable material such as TFE, graphite, asbestos, etc. It is usually in the form of solid or split rings contained in a PACKING BOX that are compressed so as to provide an effective pressure seal.
Industry:Industrial valves
A rigid spacer used in the packing with packing above and below it. The lantern ring is used to allow lubrication to the packing or allow access to a leak off connection. On some of the new fugitive emission packing systems, it also acts as a stem guide.
Industry:Industrial valves
A pneumatic relay that is used to reduce the time lag in pneumatic circuits by reproducing pneumatic signals with high-volume and or high-pressure output. These units may act as volume boosters or as amplifiers. A 1:2 booster will take a 3 to 15 psig input signal and output a 6 to 30 psig signal. It has also been shown that a booster may improve the performance of a control valve by replacing a positioner. It can provide the same stroking speed and can isolate the controller from the large capacitive load of the actuator.
Industry:Industrial valves
A part of the flow passageway that is used in conjuction with the closure member to modify the rate of flow through the valve.
Industry:Industrial valves
A part that transfers a mechanical load to the packing from the packing flange or nut.
Industry:Industrial valves
A number used to describe the ratio between the pressure recovery after the vena contracta and the pressure drop at the vena contracta. It is a measure of the amount of pressure recovered between the vena contracta and the valve outlet. Some manufacturers use the therm K<sub>m</sub> to describe the pressure recovery factor. This number will be high (0. 9) for a globe style valve with a torturous follow path and lower (0. 8 to 0. 6) for a rotary style valve with a streamlined flow path. On most rotary products the F<sub>1</sub> factor will vary with the degree of opening of the valve closure member. Note! F<sub>1</sub> does not equal K<sub>m</sub>.
Industry:Industrial valves
A material that is harder than the surface to which it is applied. It is normally used to resist fluid erosion or to reduce the chance of galling between moving parts. Hard facing may be applied by fusion welding, diffusion, or spray coating the material. Alloy #6 or Stellite is a common material used for this purpose.
Industry:Industrial valves
A flexible pressure-responsive element that transmits force to the diaphragm plate and actuator stem.
Industry:Industrial valves
