Type C3 Pressure Reducing Valve

The C3 pressure reducing valves are direct acting nozzle design, which are suitable for use on compressed air, gas, water, oil and steam. These valves are used in a variety of applications throughout industry, where their outstanding accuracy and reliability have been proven. Valves are supplied in sizes one and half inch to four inch in Gunmetal with ends screwed female or alternatively flanged to customers requirements. Inlet pressures of up to 250 psig for steam and 300 psig for air and liquid service can be accommodated, although up to 600 psig can be achieved using a reduced orifice and screwed ends. (Consult Broady Technical Sales Engineers for further information). Reduced pressure ranges of 5 to 120 psig are possible.

Pressure gauge bosses are cast on each side of the valve and tapped to customers requirements. Suitable strainers, pressure gauges, syphon pipes and cocks can be supplied when required. All valves are supplied with a nitrile disc and diaphragm for air, gases, oils, etc. as standard, but other materials are available on request. Valves for steam service are supplied with a metallic diaphragm and lid for steam and high temperature applications.

High pressure is admitted to the underside of the needle valve or disc valve. The spring is then compressed the requisite amount and the valve opened permitting pressure to pass to the service side. Expansion and consequent reduction of pressure takes place as it leaves the valve orifice and the reduced pressure is then controlled by the reaction of the spring to the reduced pressure acting upon the area of the piston. If the reduced pressure tends to fall, the spring, through the medium of the diaphragm, opens the valve and increases the orifice area. Conversely, if the pressure rises the valve closes until the required downstream pressure is restored; uniformity of the reduced pressure is thereby maintained within very close limits. The reduced pressure can be varied to requirements by
compressing or relaxing the spring. The adjusting screw is provided for this purpose. Compressing the spring increases the reduced pressure, relaxing the spring decreases the reduced pressure.

All valves should be fitted in a horizontal pipeline with, flow in the direction of the arrow cast on the side of the body. The adjusting screw should be directly above or below the pipeline. The pipe must be clean and free from dirt, scale, etc. It is advisable to fit a stop valve on the high pressure side of the line. A relief valve should always be fitted where dead end conditions apply. This can be combined with the reducing valve but we recommend that it be fitted in a convenient point in the reduced pressure line.

Type_C3.pdf