2 B&G Circuit Setters in Series

[BronYrAur]

B&G recommends a maximum of 25' DP across its circuit setters. In a campus distribution system, I have a couple of buildings near the chiller plant that are seeing more than 25' across their circuit setters. The most remote (longest TEL) branch has its circuit setter wide open. The buildings in question have their circuit setters cranked way down due to their proximity to the plant.

It has been suggested to put 2 circuit setters in series so that the pressure drop across each one is less than 25'. Anyone ever done this? I don't think I have even seen it before?

 

[lukaiENG]

What is suggested should work, the first valve is basically used as a throttling valve and the second for "fine tuning".
I would suggest that the best approach would be to balance the buildings with circuit setters on the building feeds (or better yet PICVs) then have a regular circuit setter at each coil within the building.

 

[BronYrAur]

I should have mentioned that this distribution goes to a bridge in each building with a control valve. closely spaced tees connect to the bridge with building pumps handing each building. The chiller plant secondary pumps just sends water to the bridges. So the challenge here is to balance all the bridges, but we are seeing more than 25' drop across some of the bridge circuit setters.