DOUCHES !!??!!??!!????

[plumb_know]

HI Everyone,

just after some clarification, i have been asked to install 3 douches in bathrooms from a mains fed hot & cold water system. from my understanding douches installed within vicinity of the toilet pan represent fluid category 5 risk. The back flow prevention for this is an air gap either in the form of being fed from a cistern or DC interrupter downstream of the douche valve?

I have had a look online and believe i am right in saying there are no back flow prevention devices that can be placed on the incoming mains supply to the douches that meet regulations?

appreciate the feedback
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I believe the only way i can do the installations without installing a header tank to supply the douches would be to install the douche valve higher than 300mm above toilet rim and have the DC interrupter on the outlet of valve and attach the hose to the outlet of DC interrupter. I am guessing i would have to put flow restrictors in place on the inlet the the douche valve to ensure water does not come out the sides of the valve as it flows through??

 

[ShaunCorbs]

correct cat 5 backflow, the only real way is as you say tank as dcs dont like shower hoses they create too much back pressure so they keep failing / dripping

also dont for get about hot water

i normally install a cat 5 header tank and a single impella pump (uni) then a small undersink water heater (Cistern AB Air Gap Wall Tray - Fluid Category 5 & Break Tanks - Backflow Prevention Devices - Products - https://www.arrowvalves.co.uk/shop/backflow/fluid-category-5/cistern-ab-air-gap-wall-tray)

have a look at arrow valves

 

[plumb_know]

I take it this also applies to bidet?
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*with hoses

 

[Stigster]

Yes, any bidet with ascending spray or hoses that can be submerged. Bidets that fill from above the spillover point with the required air gap can be treated just like you would any basin though.

Spray heads for toilets (AKA a "shataf"which is a word I love) and bidets with submersible outlets are a bit of a nightmare to retrofit but fine if it can all be done to regs. You are correct that there are no mechanical backflow prevention devices that can protect against Cat. 5 risks. It's all about air-gaps one way or another with these things.