What is the ZCV – Zone control valve
It is a group of valves that are installed in each role or area on the cross main pipe line, and it is the main pipe entering the role, and the ZCV is the same diameter as this pipe. The purpose of its use is to isolate or separate this area when carrying out maintenance work
ZCV consists of the following components:
OS & Y gate valve
test and drain valve
water flow switch
pressure reducing valve (PRV)
Each of these valves will be dealt with in detail:
First: OS & Y gate valve
This type of valves (gate valves or knife valves) is generally used as a closing or opening valve for the purpose of isolation when carrying out maintenance work, so it is called ISOLATION VALVE
There are two types of gate valves
rising gate valve-1 is used in fire networks
non rising gate valve-2 It is used in air-conditioning networks, and there is a type of valve called butter fly valve. It is similar in its function to the gate valve, but it is smaller in size and higher in price.
Second: tamper switch
It is a device that is installed on the OS & Y gate valve or on the butterfly valve for the purpose of monitoring or supervising it
This device is connected to the fire alarm panel in the building and gives us an alarm if the gate stop is closed. It is a box with contact points and a feather or arm that touches the screw of the stopcock
Third: (check valve) non return valve
This valve is used to prevent the reverse flow of water, meaning that it allows water to pass in only one direction.
The riser pipe that feeds the sprayers and boxes together is called the combined riser, and the system is called the combined system. And according to the American Fire Code NFPA, a check valve must be installed within the components of the ZCV to prevent water from being filtered from the network when using the fire box at the time of the fire
Fourth: water flow switch
It is a feather or a metal gate that is placed inside the pipe in the way of the water and is connected to the fire alarm panel. In the normal situation, the water in the pipes is static and there is no flow, but in the event of a fire, the water flows and the blade of the device moves and opens the circuit and gives us an alarm and through the panel it is possible to determine the location of the alarm
V: pressure gauge
The pressure reducing control valve is an automatic control valve used to reduce high pressure in water lines to a pressure of the required value.
Sixth .: test and drain valve
It is used to wash and test the network or filter water in a specific role for the purpose of carrying out maintenance work.