Unvented calorifiers must be fitted with a pressure & temperature relief valve to protect the system from excess temperature. The pressure and temperature elements of the valve operate independently providing dual safety protection in one valve. Temperature protection is provided by a wax capsule thermostat. The valve discharge must be unrestricted and piped to a safe area.
Sacrificial anodes can be supplied to counteract certain adverse water properties. Magnesium anodes help to protect glasslined tanks whilst the initial deposit of scale forms on the shell. The combination of copper pipework and glasslined tanks should be avoided. The life of the magnesium anode depends on the quality of the water and regular checks should be made to establish a service period. Aluminium anodes can be fitted to copper tanks to give lasting protection. This is only necessary for fresh water supplies which are known to prevent the formation of the natural protective oxide film. Aluminium anodes do not require replacement and are maintenance free.
On an unvented system a 20mm expansion relief valve must be fitted to the incoming cold water supply. Isolation valves must not be fitted between this valve and the calorifier. The expansion relief valve protects the system from overpressure due to failure of the expansion vessel, ie loss of vessel air charge and/or damaged bladder.
Pressure reducing valves maintain a constant cold fill supply pressure to the calorifier. This protects it from the cyclic operation of the booster set and any overpressure as the booster pumps charge accumulator vessels. Pressure reducing valves are supplied with Water Research Centre approval in bronze and cast iron. Pressure gauges can be supplied on the inlet and outlet flanges for visual verification of pressure drop.
Direct electrically heated calorifiers must be fitted with an independent high limit cut out device. All other systems require an independent high limit thermostat directly connected to the control device or to an independent shut off device.
It is fitted on the inlet connection and allows only unidirectional flow of water into the storage tank, thereby preventing emptying of the tank in case of pressure drop on the line.
It is mounted on top of the tank and allows free passage of air through it in order for the tank to be completely filled with water at the time of installation. As this function can also be achieved through T&P valve or purging of air from the outlet, this connection is left as an option.
We strongly recommend the fitting of a low water cut out device on all electrically heated calorifiers. This prevents the risk of switching the immersion heater on when the calorifier is empty.
Connections to mount the temperature & pressure gauges are provided on top of the unit. Generally, the temperature and pressure gauges are installed in the hot water connection delivery line at the site. Hence, these connection on the Calorifier itself are left as an option.
Valves are provided seperately on inlet & outlet connections, so as to isolate the calorifier from the whole plumbing system as and when required.
Thermowells are tubular fittings used to protect temperature sensors installed in industrial processes. A thermowell consists of a tube closed at one end and mounted in the process stream. A temperature sensor such as a thermometer, thermocouple or resistance temperature detector is inserted in the open end of the tube, which is usually in the open air outside the process piping or vessel and any thermal insulation. The process fluid transfers heat to the thermowell wall, which in turn transfer heat to the sensor. If the sensor fails, it can be easily replaced without draining the vessel or piping.
Two eye shaped hooks with threaded ends are screwed on the corresponding sockets which are welded on the top dome of the storage tank. Effective use of both hooks with appropriate chain links facilitates safe movement of the units.
The power from the main is supplied to the control panel mounted on top of the terminal box. It contains the power circuit and the control circuit for the heating elements and thermostats, including all electrical safety devices.