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£420.00 £504.00 inc. vat
Backflow Prevention Device primarily intended for filling and pressurising sealed house heating systems, or non-house systems, which have been risk assessed by the water supplier and downgraded to a Fluid Category 3 risk. A Type CA device – with suitable pressure regulation – can be permanently connected to a small heating system without the need for a removable filling loop. This enables the system to be filled and pressurised. A non-house primary circuit or heating system is classed as a Fluid Category 4 risk by default and a BA device can be used for filling and pressurising – see “Autofill”. The CA device affords permanent Fluid Category 3 protection. The relief port affords better protection than a double check valve (Type ED) and a CA device may be permanently connected – no removable filling loop required. A discharge pipe should be connected to the integral tundish. Under normal operation the unit should not discharge. The valve will discharge a tiny quantity of water if the supply pressure falls below about 0.5 bar or 110% of downstream pressure. A continuous discharge could occur if debris becomes lodged in the relief valve or the second check valve during a backpressure condition.
Filling house heating systems (of any output power); Filling non-house heating systems (risk assessed); Other applications approved by the local water company.
Where indicated on the drawing, a filling valve assembly shall be installed – model CA573PRV – as manufactured and distributed by Arrow Valves Ltd – Tel 01442 823123 www.arrowvalves.co.uk. The assembly shall consist of a CA device, which is suitable for permanent fluid category 3 protection, inlet and outlet servicing valve and pressure reducing valve complete with gauge. A 21.5 mm “overflow” type pipe shall be connected to the tundish. Whilst there is no operational discharge, provision should be made for a small discharge. The assembly shall be fitted in place of a filling loop.