Valves & Fire Hydrants

Single Air Valve (Small Orifice)

Used to automatically release pressure in a section of a pipe during normal operations

Single Air Valve (Large Orifice)

Used to automatically release and admit air that may accumulate under pressure in a section of a pipe during the time of initial charing or draining of mains

Double Air Valves

These valves are simply a combination of small and large orifice air valves with common connection to the mainm small orifice function being similar to that of a single aur valve. Large orifice serces for automatically exhausting air when a pipe is being filled with water, or automatically ventilating a pipe when it is being emptied of water

Kinetic Air Valves

Similar to the conventianal double air valves, these valves has certain refinements and are suitable for high head pipe lines where high rates of air discharge and ventialtion is required

Double Flanged

Wafer Type

Reflux valves are generally used on rising mains as they permit water to flow in one direction only and check all the return flows. They are operated by pressure alone, having no external means of control

Reflux valves are designated by Nominal Pressure defined as maximum permissible gauge working pressure

All flanged are faced and drilled as per IS-1538/1993. However as special cases flanges may be drilled as per BS and ANSI standards upon request to the project’s specific requirements.

Sluice valves generally come with cap or hand-wheel at the top for operation. However vales with spur gear, bevel gear, worm gear, head stock arrangements, chain wheel arrangements, by-pass arrangements may also be supplied as per project requirements.

A foot valve is generally placed at the lower end of the suction pipe of centrifugal pump to prevent the suction pipe from emptying while the pump is at rest. Consequently, when the pump is first started it does not have to exhaust the air from the suction pipe with the result that prompt starting off the pump is secured. Foot valve is particularly useful when the suction lift or vertical height of the pipe is considerable.

Types

Swing Type

Lift Type

Cast iron fire hrdrant are used for fire gighting purposes to derive water from the main underground water pipe line. Fire hydrant valves contains two tpye.

Types

Stand post type

Underground sluice valve type

Reflux valves are generally used in rising mains to check return flows. In large diameter pipes, the door, in single door pattern would close slowly and reflux flow would cause water hammer due to surge. Therefore multi-door pattern is resorted to in such cases, so as to reduce the time required for closure. The flow may be controlled by means of flaps swinging up and down with pressure on the sears. The minimum number of doors in the dioaphragm plate shall be two.