CH drain cocks - Type A or B?

[richbraithwaite]

Hi there,

Hopefully a simple one this?

I'm instsalling the pipework for my central heating system and am dropping the pipes to the downstairs rads from the void above. As such I need to include a drain cock below each rad for draining the system down; however, after looking through the Screwfix catalogue, it's apparent there are two types a heavy-guage (?) type A and a Light-guage Type B!

Which do I need? WHat's the difference?

Please help!

Cheers in advance, Richard

 

[Nige F]

Heavy good light total crrapp

 

[JohnD]

have you considered the lockshield valves with drainoff incorporated? Will save time effort and money if you fit them at initial installation.

or

 

[richbraithwaite]

have you considered the lockshield valves with drainoff incorporated? Will save time effort and money if you fit them at initial installation.

or

I thought about this as an option; however, means drain points wouldn't quite be at the lowest point, i.e. there'd still be a loop of water in both return and flow pipes beneath the rad.

Guess this doesn't matter though?

Rich

 

[JohnD]

Having a drain at every rad is more than most people get, I reckon the bit remaining in the bottom pipes isn't significant.