When replacing a ball valve in a cold water tank in a loft. Are there two types of ball valve. a part 1 & Pt 2

Question

My Mum has had the ball valve replaced in the cold water tank in her loft with the same type of fitting that came out (like for like), but she has since been told that it should have been replaced with a
"Part 2" ball valve and not a "part 1" in case of "contamination". I have never heard of Pt1 or Pt2 ball valves. Are there such things ? And if so what's the difference ?

Answer 1

A part 1 ball valve has a straight arm to which the float is attached. A part 2 ball valve has an arm that is bent 3/4 of the way into a right angle.

A part 2 ball valve reduces the amount of water in a tank. thus the water level will be lower.

Contamination could occur to the water tank if water is too close to the top of the tank, however this is quite unlikely.

There is no hard and fast rule or law to do with ball valves in water tanks and is more down to personal preference.

Answer 2

Water Tank Ball Valve

Answer 3

It s BS 1212, part 1 or part 2.

Part one has a piston and bottom outlet. Not fully compliant with Water Regulations in UK as the float arm has to be bent to adjust the water shut-off level.

Part two has a diaphagm-type washer and top outlet. The top outlet makes the risk of backflow less as the valve can be partially submerged in water but if the water supply fails it will not be able to suck up water from the cistern.

There is not necessarily a backflow risk with a part one. What does the tank feed?

The water in the cistern may be wholesome (drinking) water and so backflow is not really a problem. If it s the expansion tank for the radiator watert, a part one valve would need additional backflow protection fitted in the pipe feeding it.

Equally, a badly installed part 2 valve might also require backflow protection. Most of the plumbing I come across would not comply with the water regulations for new installations.

If it were my own house,and (worst case) the radiator water (heating feed/expansion cistern), I would be happy with a part 1 provided that the overflow is low enough and effective enough that the valve would never become submerged in water, but if I were replacing, I would fit a part 2.

Answer 4

If it's the standard design all you need is a pair of pliers to straighten and pull out the split pin that retains the float arm. You may also have to unscrew the end cap, if it has one. The plunger should then slide out. Also check the condition of the end of the jet or nozzle the washer seals to. They sometimes get pitted if a bit of grit has been trapped in them & won't seal with just a new washer. The newer type plastic ones generally have a body that opens with a large nut or knurled ring. You can get a 'universal' ball valve seal kit from B&Q that has various individual seals, a complete ready to use plunger & jet for the old valve and a diaphragm seal for the common plastic valve. If you need to replace the whole thing, you need two good quality adjustable spanners to be able to loosen and tighten things without bits twisting. Make sure you have a spare seal for the union that fits the outside of the ball valve as they often disintegrate when dismantled... It's generally a red fibre washer as used with tap connectors, again available in packets from B&Q etc.

Answer 5

I think its a load of ballcocks