Make-up and air removal questions

[gorsuchmill]

I'm lining up all the materials for my Tarm install and have a couple of questions:

1) What benefit does an air separator have over an air scoop? My oil boiler uses a scoop and I was going to add the same for my wood boiler given the significant cost difference between scoops/separators?

2) My install diagram shows separate make-up water feeds for the oil and wood boiler runs. Is it possible to simply have a T after the pressure reducing valve and send a feed to each setup instead of having separate PRVs, backflow preventers, etc.? The latter would result in less piping and less cost if it is doable.

Thanks, in advance.

 

[Nofossil]

I'm lining up all the materials for my Tarm install and have a couple of questions:

1) What benefit does an air separator have over an air scoop? My oil boiler uses a scoop and I was going to add the same for my wood boiler given the significant cost difference between scoops/separators?

2) My install diagram shows separate make-up water feeds for the oil and wood boiler runs. Is it possible to simply have a T after the pressure reducing valve and send a feed to each setup instead of having separate PRVs, backflow preventers, etc.? The latter would result in less piping and less cost if it is doable.

Thanks, in advance.

I believe that an air separator offers a higher profit to the supplier ;-)

I think it also does a more effective job at extracting air, especially small bubbles.

I don't know of any reason to have duplicate make-up water. I have a single supply, and that seems to be typical. Each boiler does need its own pressure relief.

 

[gorsuchmill]

Thanks Nofo. Would you simply use a single air separator downstream of where the oil and wood boilers tap into the supply, with an expansion tank and make-up off of the single separator?

Also, where can I acquire purging valves? I've looked on-line and can't seem to track them down. I'm disinclined to use my local plumbing supplier because they seem to want to gouge me. For example, I was quoted $110 for a Watts T&P;valve for my hot water heater and was able to find the same item on-line for about $20 with shipping. Maybe it was an honest mistake, but those types of things seem to happen more frequently than sumple oversight would suggest. I suppose I shouldn't wear a coat and tie (my work get up) when going to the supply houses.

Thanks again for your help.