Valves and control devices include:
- isolating valves – manually operated valves for isolating one section of the system from the rest
- line strainers – filter particles of solid matter from the water to protect other valves downstream
- non return valves – prevent reversed flow within, or from, the system
- pressure-reducing valves – automatically reduce the pressure to a preset level
- pressure-limiting valves – limit the pressure within preset limits
- expansion control valves – release pressure in the cold water feed pipe caused by expansion of water in the heater during normal operation
- energy control thermostats – control the input of heat energy to the water
- temperature and pressure-relief valves – release pressure in the storage cylinder if it rises to more than a preset limit
- energy cut-outs – cut gas/electricity supply to the heater if the thermostat fails
Valves must be installed so they are readily accessible for operation, maintenance and repair.
For more technichal information please click the links below:
- Pressure Limiting Valve explained
- Pressure Limiting Valve explained (Ajax valve)
- Cold Water Expansion Valve explained
- How a line strainer works
- How a non return valve works
- Common Tempering Valve explained
- Tempering Valve sectional view
- Temperature and Pressure Relief Valve
- Pressure Reducing Valve sectional view
- Pressure Limiting Valve 3 in 1
- Filter Stop and non Return Valve sectional view
- Isolating non Return Valve sectional view
- EVT Low Pressure sectional view
- Combination Isolating and non return Valve
- Pressure Limiting Valve sectional view
Before viewing installation the following installation diagrammes please note that in New Zealand ONLY a registered plumber is allowed to fix or unfix any sanitary fixture, sanitary appliance, or any associated fittings or accessories. This includes ALL the above mentioned valves and fittings. This is more clearly defined in the The Plumbers, Gasfitters and Drainlayers Act 2006.