Backflow prevention

[plumber0808]

What would be a suitable means of preventing backflow for a wash station Belfast sink, hot & cold to tap that has a long arm off it leading upto a spray head that can potentially be submerged in the sink.

Sink is at a meat processing factory.

many thanks guys
Colin

 

[SafeGasInstall]

two double check valves and air gap , I think this is the heights risk one

did read some where also a water break tank ,but not sure

 

[Mike Jackson]

You need Category 5 protection so only an air gap will do.

Have a look at

Arrow Valves Ltd - Ablution Plant for an all in one solution or Products - "Midi-Break" - BTMIDI for one that feeds another heater.

For larger water quantities they also do larger boost sets.

 

[AWheating]

if it was a domestic property then it would depend on the water cat in the basin. In a commercial situation its probably going to be a different set of rules tbh and may need an air break or an expensive valve but im not sure.

edit: read mikes post.

 

[Mike Jackson]

It's not a basin, it's a sink. Sink is always Cat 5 regardless. Basin in domestic is 3, in care home, hospital etc. it's 5.

 

[AWheating]

Cat 5 = :001_9898:

 

[plumber0808]

Yes was just looking at defra website regarding category 5 break tanks and air gaps.

if the spray head can not be submerged then do I still have to use the same set up or will an acceptable air gap and double check valves be sufficient?

 

[Mike Jackson]

If the spray hose cannot be submerged then air gap will deal with backflow from sink and single check valves will be sufficient as we are looking at Cat 1 for the cold and Cat 2 for the hot.

Issues could arise if they are using the equipment to wash buckets etc. out that could submerge the spray head. If you know that the spray is used for this sort of thing then you are back to using a break tank.

Have a look at Plumbing Supplies | BES Gas & Plumbing Fittings and search for Commercial ‘Pre-Rinse’ Spray System to see a suitable spray system.

 

[plumber0808]

Thanks mike. Running over it in my head, just confusing myself in the end.

Just want to make sure I've got no comebacks. Cover myself before anything.

 

[SafeGasInstall]

MJ you are the man !!!

 

[SafeGasInstall]

Thanks mike. Running over it in my head, just confusing myself in the end.

Just want to make sure I've got no comebacks. Cover myself before anything.

could you not ring local building inspector and tell him what you are planing to do and ask for help ?

 

[Mike Jackson]

Building inspector won't have a scooby. The water inspector from the local water undertaking is the person that you need to speak to for this sort of thing.

 

[AWheating]

same thing applies with showers that can reach toilet pan. you must create an air gap. a shower screen as a barrier or a fixing on the hose/riser bar.