I wonder if any plumber can advise me on pipe interrupters.
I am completely replacing our en-suite bathroom.I am installing a shower above a bath. The bath and shower are to be feed from a Hansgrohe bath-shower mixer. The bath has an Exafill bath filler with overflow and waste where water fills the bath basicall through the overflow, i.e. there are no taps. The Hansgrohe "ibox universal" manual on page 10 shows a pipe interrupter fitting in line between the shower/bath mixer and the Exafill on the bath. This appears to be a UK requirement. I've looked at the DEFRA Water Supply (Water Fittings) Regulations 1999 to try and understand exactly what is required in terms of a pipe interrupter but is hard going getting to grips with all this information.
The appropriate section from the Regs seems to be
"Submerged inlets to baths and washbasins
G15.14 Submerged inlets to baths or washbasins in any house or domestic situation are considered to be a fluid category 3 risk and should be supplied with water from a supply or distributing pipe through a double check valve. Submerged inlets to baths or washbasins in other than a house or domestic situation, and sinks in any location, are considered to be a fluid category 5 risk and appropriate backflow protection will be required. "
Which seems to imply I must use a pipe interrupter to comply with the regs.
My house has no cold tank, it's direct from mains and I have a pressurised hot water tank.
So can anyone tell me :-
a) What type of pipe interrupter do I need ?
All the pipework and the bath/shower mixer is going in behind a false partition on the wall above and behind the bath which will then be tiled.
b) If I need to use an air-gap type pipe interrupter can this go in the partition completly hidden or do plumbers fit some kind of chrome pipe interrupter version designed to be visible ?
c) Would a "non-return" valve do the same thing ?
Many thanks for any info or light that can be shed.