PDA

View Full Version : Chilled water wet-tap


marauderx
09-28-2006, 03:55 PM
What's the largest chilled water line you'd wet tap?

I got a customer that wants to wet tap a 3/4" line into a 12"+ chilled water supply and return line for a supplemental fan coil unit. Sure, I can make the wet tap, but control the flow on chilled water lines that big? Any advice?
hands
09-28-2006, 05:35 PM
You wouldn't be controlling the flow on the 12" chilled water lines, you would control the flow on the 3/4" line that you are adding. As far as how big of a pipe can you "hot tap" into, bigger the better.
flange
09-28-2006, 06:24 PM
I have done six inch taps into eighteen inch risers. what you got dere aint no thang
marauderx
10-02-2006, 09:49 AM
The problem I have is that I don't know the pressure on those large chilled water lines and if I'll need to do anything to bring it down for a ~5-ton fan coil I'm adding nearby.

But what's the worst that could happen, right??
flange
10-02-2006, 03:47 PM
not knowing the pressure isnt that big of a deal. just estimate static pressure based upon the height of the building and add a factro to that. 500 foot high building , roughly 250 in the basement then add floors. cmon this aint that hard. once rough pressure is known you can order fittings accordingly.
marauderx
10-04-2006, 03:19 PM
Well, this isn't a riser. It's a chilled water main for 5 buildings from the plant. We'll prolly go with a split system anyway, since now the scope has changed (doesn't it always?).
btj steamfitter / ref
10-04-2006, 09:38 PM
I think I'd hot tap like a 2" line on that way they have some future capability wont have to do it again if you only do a 3/4" maybe even get a few extra bux out of them for it
marauderx
10-09-2006, 11:13 AM
Turns out its 10" chilled water supply & return lines. Plus they only serve 1 building.

We're proposing a 1-1/2" line for about 60' run for future capacity... we'll know today if they want to buy the bigger pipe & insulation.
hvac69
10-22-2006, 03:52 PM
I would be concerned about pressure, had a job that was engineered on the west coast, job was on the east cost, engineer never seen the building just a blue print showing the retail space and apparently didnt realize the building was 30 storys high and the cooling tower was on the roof. He couldnt understand why the 1 hp pump wouldnt move water through the WSHP's