Low Pressure Chillers

[grendil]

Gents:

Releif piping question on three (3) Trane Cvhf R-123.
The existing 11 Machines were 2 inch Releif outlets. The new proposed chillers 123 are 3 inch.

My question is if they are common vented all releifs connected together what pipe size will need to be used? 3" times 3 machines = pipe size??

The chillers will have rupture guards on them, I don't know if that makes a difference on Code and pipe size.

The fitters want to use welded pipe. I have seen sch 80 PVC and copper also.

Thanks

[Healey Nut]

If you can avoid it dont common the lines together ,1 chiller one vent line !!!
Heres why ..#1 chiller has a tube failure and fills with water the water pressure is higher than rupturedisk pressure and breaks the disc ,common vent line fills with water ,chiller one shuts down water still filling chiller #1 .Vent line is going to roof ten storeys up standing water pressure is now increasing(as vent line fills) .Standing water pressure now causes rupture disks on chillers #2&3 to IMPLODE filling two perfectly good chillers with water . You now have an enormous bill for repair instead of a few hundred bucks for some extra piping ????? See my point ?????? And no operating chillers ?????
I'll say it again ONE CHILLER ONE VENT LINE !!!!!!!!!!!!!!!!!!!

[klove]

Single and common line sizing is in the ASHRAE code, look there. Unless you have a horizontal run of common line that NEVER turns vertical, I completely agree with graham. Even then I believe in dropping the individual lines into the top of the main.

[jemawalton]

I vote for seperate vent lines. Also make sure they vent the purge AFTER the rupture gaurd. Found one the other day that was tied into the stub provided on the spool piece just after the rupture disk. They then placed the rupture gaurd on this same piece. Ran this way for 3 years. They got lucky.

[supertek65]

my vote too!

If you can avoid it dont common the lines together ,1 chiller one vent line !!!
Heres why ..#1 chiller has a tube failure and fills with water the water pressure is higher than rupturedisk pressure and breaks the disc ,common vent line fills with water ,chiller one shuts down water still filling chiller #1 .Vent line is going to roof ten storeys up standing water pressure is now increasing(as vent line fills) .Standing water pressure now causes rupture disks on chillers #2&3 to IMPLODE filling two perfectly good chillers with water . You now have an enormous bill for repair instead of a few hundred bucks for some extra piping ????? See my point ?????? And no operating chillers ?????
I'll say it again ONE CHILLER ONE VENT LINE !!!!!!!!!!!!!!!!!!!

[heavymetaldad]

ditto.as far as piping material, depends on your codes. i'm in chicago. all we see is iron pipe.

[supertek65]

ditto.as far as piping material, depends on your codes. i'm in chicago. all we see is iron pipe.

good 4 da fitters!

[drivewizard]

If you can avoid it dont common the lines together ,1 chiller one vent line !!!
Heres why ..#1 chiller has a tube failure and fills with water the water pressure is higher than rupturedisk pressure and breaks the disc ,common vent line fills with water ,chiller one shuts down water still filling chiller #1 .Vent line is going to roof ten storeys up standing water pressure is now increasing(as vent line fills) .Standing water pressure now causes rupture disks on chillers #2&3 to IMPLODE filling two perfectly good chillers with water . You now have an enormous bill for repair instead of a few hundred bucks for some extra piping ????? See my point ?????? And no operating chillers ?????
I'll say it again ONE CHILLER ONE VENT LINE !!!!!!!!!!!!!!!!!!!

Good advice, only thing I might add is make sure it has a drip leg at bottom with a valve to drain or check for moisture.
Make sure they put an 180 deg turn at top if it goes vertical thru roof to keep rain out.
Could put some sort of wire mesh to keep the birds out also. I found a "Bird of Love" sitting right in front of a rupture disk one time. Was pretty well preserved, the refrig vapor from purge probably kept it from spoiling.
It looked so real it startled me a little, it had made its way down and across several hundred feet of pipe. Then just stopped and croaked.

[Chiller Guy]

Are there any drawings for this job? Hopefully, someone sized the relief piping for this installation as well as specified the type of pipe and connection methods. If not (sounds like the case) Try to stay with one vent line per machine. Having a common header may be nice, and cheaper, but if not sized properly, and a machine blows a charge, you may get back pressure on the other two machines relief devices. Maybe a problem and maybe not! Why chance it? Also, make sure there is no weight on the relief device (vibration isolator) too. And just for laughs and gigles, Make da-- sure the fitters pipe the condensers for the proper flows. Have had two 1500T in the last three yrs piped backwards.

[supertek65]

DRAWINGS?

Are there any drawings for this job? Hopefully, someone sized the relief piping for this installation as well as specified the type of pipe and connection methods. If not (sounds like the case) Try to stay with one vent line per machine. Having a common header may be nice, and cheaper, but if not sized properly, and a machine blows a charge, you may get back pressure on the other two machines relief devices. Maybe a problem and maybe not! Why chance it? Also, make sure there is no weight on the relief device (vibration isolator) too. And just for laughs and gigles, Make da-- sure the fitters pipe the condensers for the proper flows. Have had two 1500T in the last three yrs piped backwards.

[Chiller Guy]

Yeah! Those little lines they put on paper to represent pipes, valves, chillers,etc. You may have seen them in your travels.

[supertek65]

Yeah! Those little lines they put on paper to represent pipes, valves, chillers,etc. You may have seen them in your travels.

Oh yeah! my boss told me about those once!

[heavymetaldad]

Yeah! Those little lines they put on paper to represent pipes, valves, chillers,etc. You may have seen them in your travels.

the squiglly lines on the back of a bar napkin?

[supertek65]

you thought i wad stupid!
but i know what drawings are!

Yeah! Those little lines they put on paper to represent pipes, valves, chillers,etc. You may have seen them in your travels.

[Chiller Guy]

You having a slow TV night too?

[supertek65]

You having a slow TV night too?

I am watchinh hole in the wall.
google brooke burns the hostess with the mostess

[supertek65]

the squiglly lines on the back of a bar napkin?

napkin sketch

[Chiller Guy]

OK, you have my curiousity aroused! Where is Tonganoxie KS? I used to live in Salina. Have been to Wichita, Abelene, the KC Trane office, and points West but never Tonganoxie.

[supertek65]

OK, you have my curiousity aroused! Where is Tonganoxie KS? I used to live in Salina. Have been to Wichita, Abelene, the KC Trane office, and points West but never Tonganoxie.

West of kansas city kansas, east of Lawrence
North of Olathe