Working principle of Fairchild pressure reducing valve

Brand

FAIRCHILD/Fairchild Technology (USA)

Application Areas

Environmental Protection, Biotechnology, Petroleum, Pharmaceuticals/Biopharmaceuticals, General Industry

Fairchild Pressure Regulator Working Principle

FAIRCHILD Sensors

FAIRCHILD Pressure Regulators

FAIRCHILD Control Valves

FAIRCHILD Inverters

FAIRCHILD Controllers

The Fairchild pressure regulator controls compressed air pressure P1. The air enters from the left end, is throttled through valve port 10, and the pressure is reduced to output pressure P2. P2 can be adjusted by adjusting springs 2 and 3. Rotating knob 1 clockwise compresses springs 2 and 3 and diaphragm 5, causing valve core 8 to move downwards, increasing the opening of valve port 10 and thus increasing P2. Rotating knob 1 counterclockwise decreases the opening of valve port 10, and P2 decreases accordingly.

If the input pressure P1 of the Fairchild pressure reducing valve increases instantaneously, P2 will also increase, causing the pressure in the diaphragm chamber 6 to rise. This increases the thrust on the diaphragm 5, disrupting the original force balance and causing the diaphragm 5 to move upward. A small amount of airflow is discharged through the overflow hole 12 and the exhaust hole 11. Simultaneously, due to the action of the return spring 9, the valve core 8 also moves upward, closing the inlet valve 10 and increasing the throttling effect, causing the output pressure to decrease until a new equilibrium is reached, at which point the output pressure essentially returns to its original value. If the input pressure drops instantaneously, the output pressure also drops, the diaphragm 5 moves downward, and the valve core 8 moves downward accordingly, opening the inlet valve 10 wider and reducing the throttling effect, causing the output pressure to essentially return to its original value. Rotating knob 1 counterclockwise relaxes the adjusting springs 2 and 3. The thrust of the gas on the diaphragm 5 becomes greater than the force of the adjusting spring, causing the diaphragm to bend upward and close the inlet valve 10 due to the action of the return spring. Rotating knob 1 again disengages the top of the inlet valve core 8 from the overflow valve seat 4, allowing compressed air in the diaphragm chamber 6 to escape through the overflow hole 12 and exhaust hole 11, thus putting the valve in a no-output state.

In summary, the Fairchild pressure reducing valve reduces pressure through the throttling effect of the inlet, stabilizes pressure through the balancing force on the diaphragm and the overflow effect of the overflow hole; adjusting the spring allows the output pressure to be changed within a certain range. To prevent the pollution of the surrounding environment caused by the small amount of gas emitted by the above-mentioned overflow type pressure reducing valve, a pressure reducing valve without an overflow valve (i.e., a common pressure reducing valve) can be used.

The Fairchild pressure reducing valve reduces the inlet pressure to a desired outlet pressure through adjustment, and automatically maintains a stable outlet pressure by relying on the energy of the medium itself. From a fluid mechanics perspective, the pressure reducing valve is a throttling element with variable local resistance; that is, by changing the throttling area, the flow velocity and kinetic energy of the fluid are changed, resulting in different pressure losses, thereby achieving the purpose of pressure reduction. Then, relying on the regulation of the control and adjustment system, the fluctuation of the downstream pressure is balanced with the spring force, keeping the downstream pressure constant within a certain error range.

Fairchild is an American company that manufactures precision instruments. It has two divisions: Industrial Controls and Mechanical Power Transmission. Its technology and product quality are among the best in the world, with over 99 years of manufacturing experience. It consistently provides high-precision, high-quality, and highly reliable products to the processing and machine tool industries. Its main products include: • Pressure regulators • Filter regulators • M/P converters • Air volume boosters • Gas relays • Current-to-pressure converters • Voltage-to-pressure converters • Pressure-to-current converters. Fairchild has distributors worldwide, providing localized service. Our factory engineers can solve all kinds of problems for you and provide the products you need. Our reputation is built on high-quality products, excellent service, and rapid response to customer needs. Our energy transmitters offer high-quality mechanical speed change with minimal speed difference. This technology is the foundation of our development and has placed the company at the forefront of the energy transmission field. For 50 years, industry has trusted our energy transmitters for their reliable performance in speed and position control. Our transmitters are widely used in combined tension control and precise speed adjustment in printing, papermaking, packaging, and textiles. Additionally, our transmitters are used in machine tools, conveyors, synchronization, and other OEM applications. Every transmitter shipped is optimized for its specific application. Fairchild has built a strong reputation in the industry for its high-quality products, excellent customer service, timely delivery, competitive pricing, and prompt response to customer needs.

Our company primarily deals with European and American brands, and can source brands from any European country. For example, our key German brands include: FESTO, BURKERT, BOSCH-REXROTH, IFM, TURCK, P+F, BALLUFF, SICK, HIRSCHMAN, MURR, HYDAC, GSR, CROUZET, E+H, PILZ, HAWE, SIEMENS, STAUFF, EUCHNER, EMG, UNIVER, ATOS, NORGREN, and approximately 500 other brands of varying sizes from European countries. We have cooperative relationships with approximately 500 other European brands.