Unlike ordinary plumbing valves, fire service valves must be approved for the purpose (UL listed, FM approved or certified to the relevant EN standards). We select valves to suit the hydraulic design and pressure rating, wire the supervisory switches into the fire alarm system and test each valve's position signal individually during commissioning.
ATypes and components
OS&Y gate valve
The stem rises outside the body as the valve opens, so a visible stem means the valve is open. This at-a-glance check is why OS&Y valves are standard in pump rooms, alarm valve stations and main distribution lines.
Supervised butterfly and ball valves
Butterfly valves are compact and suit zone control assemblies and tight spaces. The built-in tamper switch signals the fire panel as soon as the valve starts to close; in small sizes, supervised ball valves do the same job.
Post indicator valve (PIV)
An above-ground post that operates a buried non-rising stem gate valve. A window shows OPEN or SHUT, and the post can be padlocked and fitted with a tamper switch.
Check valve
Allows flow in one direction only. It prevents backflow on pump discharge lines, at fire brigade inlets and where different water supplies meet, and comes in swing, spring-loaded and grooved-end versions.
Pressure reducing valve
In tall buildings it brings excess pressure on the lower floors down to the working pressure of hose reels or sprinkler components. Every pressure reducing valve needs a test connection downstream so that its performance can be verified.
Pressure relief valve
Discharges excess pressure where pump output could exceed the rating of system components, typically on diesel pumps whose speed can vary. It should not be confused with the small circulation relief valve that stops a pump overheating at churn.
Test and drain valve
Lets you simulate the flow of a single head through a calibrated orifice and drain the installation when needed. The orifice matches the smallest K-factor head in that installation, and flow is visible through a sight glass.
Fire brigade inlet
Allows fire appliances to pump water into the sprinkler system or rising main from outside the building. It is usually a twin inlet with a check valve and caps, located at a clearly marked point the fire service can reach easily.
Flow and tamper switches
A vane-type flow switch signals an alarm after an adjustable delay once water starts to flow, identifying the zone. A tamper switch reports any change in valve position; together they give the fire panel a live picture of the system.
Flow meter
Installed on the pump test line to measure the pump's actual output. It allows annual pump performance tests to be carried out accurately without discharging water to waste.
CAdvantages
- Continuous monitoring of valve positions
- A closed valve is flagged by an alarm
- Equipment in tall buildings protected from overpressure
- Pump and sprinkler tests carried out under control
- Approved products ease inspections and insurer audits
DApplications
- Fire pump rooms
- Sprinkler alarm valve stations
- Floor zone control assemblies
- Site hydrant and underground mains
- Rising mains in tall buildings
- Fire brigade inlet points
EFrequently asked questions
Why can't ordinary valves be used in fire systems?
A fire system can sit idle for years and must then work first time. Approved fire valves are tested for pressure rating, tightness and position indication under exactly those conditions. The standards also require isolating valves to be of an indicating or supervised type.
What should we do when a tamper switch alarm comes up?
A supervisory alarm means a valve has been partly or fully closed. First check whether planned maintenance is under way in that area; if not, inspect the valve and open it fully. If the alarm persists with the valve open, the switch or its wiring is faulty and needs fixing promptly.
How often should pressure reducing valves be tested?
NFPA 25 requires regular visual inspection and testing under flow. Common practice is a partial flow test every year and a full flow test every five years. Inlet and outlet pressures are recorded, and a valve that drifts from its setting is adjusted or overhauled.