However, insertion depths on compression joints that form part of the cylinder must be checked prior to installation and the use of standard pipe inserts (prefix TSM) is recommended. Building Regulations (Part G), discharge pipes from temperature and/or pressure relief valves must be run in metal pipework. Speedfit connections to combined Cylinder/Boiler units and Thermal Storage Units must be made outside the casing unless otherwise stated in the manufacturers installation literature.
Care should be taken when designing and installing a central heating system where radiators are supplied by pipework which drops from an upper floor. With this kind of system it is possible to trap air in the upper floor pipework. When the boiler is fired the increase in pressure within the pipe caused by expanding air could cause the pipe to burst. It is therefore essential that the system be designed so that any air can be removed from the system either automatically or manually by installing automatic or manual air vents at the highest points of the system. Speedfit pipe should not be used to provide the discharge from unvented cylinders, unvented water heaters or sealed systems via the temperature relief and pressure relief valves. Speedfit recommend that mains supply pipework to unvented water heaters (up to 15ltr capacity) be run in metal pipes. Unvented Pressurised Cylinders can be installed using Speedfit Pipe and fittings.
However if the safety parameters of the cylinder exceed those of the pipe and fittings it is possible to fit a pressure reduction valve on the out going hot supply pipe. This will not interfere with any other cylinder safety devices demanded by regulations as they are all fitted in the incoming side of the cylinder. Run a short length of copper pipe from the cylinder connection (about 150mm – 300mm) then fit a Honeywell DO5F pressure reduction valve. This will protect the pipe and fittings from excessive pressure in the event of boiler / cylinder malfunction. The factory fitted temperature / pressure relief valve on the cylinder will discharge below 100°C therefore protecting the pipe from excessive temperature. Speedfit pipe should be connected to circulating pumps and motorised valves in accordance with the above section headed “ Connection to compression fitting “. If Speedfit pipe is not mounted on a supporting structure, the pipe must be clipped close to the components’ connections to ensure adequate support and to assist in the reduction of vibration. For heavier equipment, ensure that appropriate metal brackets provide full and independent support of the components and that the equipment does not rely solely on the pipework for support. 450mm (18 inches) is the minimum distance to make a solder connection on copper pipe inserted into a Speedfit fitting. Ensure that any residual flux solder is not allowed to come in contact with the fitting. That same measurement is the safe distance to use a freezer kit to Speedfit pipe. To install the Speedfit Tank Connector, unscrew the nut and push the body of the fitting through the tank hole with the washer on the inside of the tank. Note: Hard tightening the nut onto the body is all that is required. Further mechanical tightening will damage the fitting. The Speedfit range includes a Double Check Valve (Part No 15DCV) to enable installers to comply with Water Regulations Schedule 2.15, thus preventing contamination of water arising from back siphonage, backflow or cross connection. The most common way of running pipework to a radiator is to run both flow and return pipes central to the radiator position. The pipes exit a single gang box (fitted with rubber grommets) located at the mid height of the finished radiator position. This also provides a fixed point for other trades to work to and reduces the risk of damage to the pipework. Once the plasterboard is installed the pipes are passed through the Speedfit Radiator Outlet Plate to exit plasterboard without creating unsightly holes. Metal reducing sets which convert radiator valves from 15mm to 10mm are not suitable for use with Speedfit fittings or pipe as they can cause damage to the plastic. The plumbing or heating system installer should have these aspects checked to ensure compliance with current IEE regulations. If in doubt, please contact the Speedfit Technical Advisory Service or consult your local Electricity Authority.
IEE Guidance Note 7 provides useful guidance on the design of electrical installations where there is increased risk of electric shock. It recognises that the requirement for supplementary bonding may be relaxed where metal taps and plastic pipes supply other bathroom fittings. Similarly, a metal batch or radiator not connected to an extraneous-conductive-part is not required to be connected to the local supplementary conductors. Pipe Material Supplementary bond required between Comments Cold water Hot water Central heating P P P Earth terminals of protective conductors of class I and of class II equipment and accessible exposed conductive parts of the building structure. Bonding of metal taps and metal radiators or metal baths is not required unless the bath is connected to the metallic building structure. P M M Hot water pipe, central heating pipes, earth terminals of protective conductors of class I and class II equipment and accessible exposed conductive parts of the building structure. A bond is not required to the taps (either hot or cold) or to metal baths unless connected to the metallic building structure. P P M Central heating pipes, the earth terminals of protective conductors of class I and class II equipment and access to exposed conductive parts of the building structure. Bonding of metal water taps is not required, nor metal baths unless connected to the metallic building structure.
M M M All metal pipes, earth terminals of protective conductors of class I and class II equipment, and accessible exposed conductive parts of the building structure. Metal pipes themselves can be used as bonding conductors if joints are metal to metal and electrically continuous. M M P All metal pipes, earth terminals of protective conductors of class I and class II equipment, and accessible exposed conductive parts of the building structure. Metal central heating radiator does not require bonding. P = Plastic M = Metal NB: All waste pipes are plastic.