BS1212 part 1

[Readingplumber]

Hi,

I was reading on some old revision exam papers that that the only place permitted for a BS1212 part 1 valve is in a F and E tank?

Is this a glitch, my understanding is part 1 valves are only allowed in a wc off a cws?

Please can someone advise?

Thanks

 

[buff]

im sure this is right
bob

 

[WHPES]

I seem to remember the requirements depend on the situation, means of overflow and likelihood of contamination - It is all written down in tables in the Water Regs handbook. Doesn't specifically refer to DHW tanks etc.

 

[Tbrown57]

Either way, you should fit a double check valve to prevent potential contamination caused by back syphioniage. Especially on an F & E tank that contains potentially harmful chemicals.

 

[kirkgas]

Either way, you should fit a double check valve to prevent potential contamination caused by back syphioniage. Especially on an F & E tank that contains potentially harmful chemicals.

there is no requirement to fit a double check valve on the inlet of a F&E tank, the requirement is to remove the risk of contamination by good design and installation, ie overflow position in relation to ballvalve position, and correctly setting the water level

 

[Tbrown57]

sorry mate should of phrased it a bit better, i have always been told its good practice

 

[oldplumber]

there is no requirement to fit a double check valve on the inlet of a F&E tank, the requirement is to remove the risk of contamination by good design and installation, ie overflow position in relation to ballvalve position, and correctly setting the water level

good to see someone knows the rules

 

[Tbrown57]

The Portsmouth valve is not suitable for use in WC cisterns,
unless there is a suitable backflow prevention device, e.g. a double
check valve fitted before the valve. If used on a CWSC, the valve
must have an adjustable float lever connection.

 

[kay-jay]

i was under the impression that they are not allowed in wc's any more simply because the airgap requirements to comply with water regs has changed to specify top outlet filling valves only.

KJ

 

[WHPES]

If you look in the Water Regulations you will see there are no details specifically referring to WCs or other devices. Rather there is a list of categories of water qualities and a page detailing back siphonage and contamination prevention measures.

 

[Bernie2]

Hmm!

Its best perhaps to work it out yourself. If water can go down the ball valve outlet and cause back siphonage, then its wrong.

The top outlet WC cistern ball valves are designed so that the outlet is much higher than the cisterns overflow pipe inlet, i.e it has an air gap.

The BS 1212 Part 1 has its outlet at the bottom, so its lower and so the air gap between the cisterns overflow inlet and the ball valves outlet is reduced.

So obviously a BS 1212 part 2 in brass or part 3 in plastic with an outlet on the top would be better for a cistern.