equilibrium valve - whats the bit in the washers for?

[Readingplumber]

Hi when you take apart a equilibrium valve eg torbeck compact, when you look at the washer there is a minute pin and a big pin gong through them. they have a place to sit in the valve seating - what are they for?

Many Thanks

 

[Deleted member 2053]

I would guess that they are there to keep the seal and seat in alignment. If I remember correctly the larger pin is tapered. This will affect the flow rate as the valve shuts so that it closes quietly. Just a guess.....

 

[justlead1]

Hi. Equilibrium valves work on the principal that the incoming pressure works against itself to help close the valve. The small hole may be there to allow the pressure to build up behind the washer/diaphram. This type of vale allow far more flow than a bss 1212 portsmouth pattern. Good Luck