Fitting Dump valve

[RickH]

I have 3 pressure vessels on my heating system ....
When the system is empty, the pressure was set as required via the Schraeder valve.

You shouldn't pressurise when water is on the other side of the bladder.
Had a guy in on w/end looking at a new boiler fault, and he mentioned that you can 'add' a 3 way valve to what is installed to allow you to turn the pressure vessel to 'dump' rather than 'system' and hence allow pressure fill/test.

He mentioned them as 'Flamco 3 way valve to Dumper (drain)' .... looked on Flamco site and I am not sure what it is I'd need to add ..... I attach 2 pics of the valves as installed, could someone point me to the correct item to add ?

 

[RickH]

OK ..... I have found the item
Flamco Flexcontrol 3/4M

There are 2 types a fixed 3/4 BSP female bottom thread with male BSP top thread, and an easier fit swivel lower 3/4 BSP nut, but it comes with Female compression top fitting. (see pic)
As you can see from the install pics in first post I need male 3/4 BSP on top connection......
If I simply remove the top nut, that will then provide 3/4 BSP thread, would that be a suitable connection then the 3/4 female in the valve assembly?