Boiler Purge Design Question/Suggestion

[kilkoyne]

Hi,
I was given an old wood boiler with all the controls, valves, pump, etc. I want to put it in my outdoor shop. I don't want to put a lot of money into it. I don't remember how it was originally installed.

Would I have to add a ball valve cut off after the purge valves? Why do some purge valves have cut offs built in and some don't? I'm assuming for convenience but is it needed? Can anyone see anything wrong with my design?
Thanks

 

[Leon82]

It looks ok. that webstone will replace the individual ball valve and drain.

you can till isolate the zone and purge said zone with it

 

[Sponsor]

 

[Kebo147]

In your design the pump is pumping into the expansion tank. The expansion tank is the point of no pressure change and will therefore hinder the operation of the pump and possibly create cavitation. I would move it to pump away from the boiler and be sure the head of the pump is mounted sideways. The wood boilers I have worked with were open to atmosphere. Do you have a heat exchanger with the unit? If not, will your piping go above the elevation of the boiler? Your system might operate more like a drain back solar system and placement of auto vents might need to be reconsidered.