OS&Y gate
valve used to control water flow to fire sprinkler system. OS&Y means “outside stem and
yoke” or "outside screw and yoke". OS&Y gate valves operate by opening and closing via a
gate, which lowers into or rises out of the valve.
NRS means
Non-Rising Stem. In an NRS valve, the stem will turn to open and close the gate, but the stem
does not move up or down as it turns. These valves are usually buried underground to prevent the
risk of freeze.
A butterfly valve
isolates or regulates the flow of fluid through piping systems. Butterfly valves for fire
protection serve as control valves that turn on or shut off the flow of water to the pipes
serving fire sprinkler or standpipe systems.
Swing check
valves are used to prevent back flow in the line. The pressure of the fluid passing through a
system opens the valve, while any reversal of flow will close the valve. This allows the flow of
water in one direction only.
Air release
valves are probably the most widely used type of air valve in firefighting systems. These Air
release valves automatically vent small pockets of accumulated air during startup and as they
accumulate in fire protection systems.
Test and Drain
Valve is a type of ball valve used in fire systems, especially for testing whether the system is
working or not. The ball used in the test and drain valve consists of 3 positions as test, drain
and off. The drain position ensures that it can be used as a drain valve when requested. The
flow through the sight glass on both sides of the Test and Drain Valve can be observed.
Motorized valves
are the type of valves, if electric motor is equipped and geared with the valve stem so that
when the motor operates, the valve will open or close. An actuator is used in MOV( Motor
Operated Valve). These valves allow the flow to be stopped, started, and adjusted as necessary
to ensure that operations continue as scheduled.
