Ever heard of?

lchmb

Has anyone ever heard of trapping a return? I am starting a replacement of a system that is having problems with ghost flow. The system is made up of 3 baseboard zone's, 1 HW tank and 2 radiant zones. All fed by circulators and flo checks. When I mentioned this to my supervisor he told me to put a trap on the return? He indicated to bring my boiler piping out and drop it 12" (this is a Buderus). I have never heard of this and was just curious if this is something that helps with ghost flow?

Al Letellier_9

traps

Yes it can be an effective way of helping with "ghost flow"
A trap will prevent the gravitational flow of water 'cause heated water wants to rise and won't flow downhill....if ghost flow is the problem. Make sure that the multiple circulators aren't creating more head than the flow checks can prevent....look the system over and think like water...where would you go if you were in those pipes.
Another flow check may be required...on the return.

Christian Egli

How hot water can be baffled by the simple things

Awww, you fooled me, I came here looking for steam traps...

But, yes, these trap type piping arrangements work. The hotter water migrates to the top, just like air bubbles do. Your piping arrangement will serve to trap the hot water, just as it would an air pocket. Instead, you'll have a "water pocket". The slug of hot water will be so confused it won't know which way to go down to get out; it'll stay put and you won't have ghost flows, or at least less.

But it is not always foolproof, you might have to come back and increase the depth of the trap. This is probably in relation to delta T's. Spooky!

Many times the trap will easily stop a ghost flow from starting on its own, but it will not be able to stop one that has been established previously through pumping circumstances.

By the way the trap can work on either side, pointing down to confuse the hot water, and up for the cold water.

Stagnant air inside a big warehouse can be fooled the same way. By installing baffles on the ceiling that resemble partition walls. Again it is not a total stop to migration but a big reduction.

Now, steam on the other hand, you can't fool it. It's too smart for its own good...

Happy piping.

bob young

heat sink

we use a 27 " heat sink trap for holby mixing valves in lieu of a check valve. mechanical parts are prone to hanging up.

Weezbo

Yes. and ..it is no guarntee that it will stop the ghost flow.

there are often other variables that have a bearing on the minor technicalities....sound advise comes from verifiable sources...and wisdom comes from counscil of many sources... i know ..by now i should be keeping my own counsel. and let experience pay its own way....let me ask does the piping have a by pass of any sort ?...other than he internal piping of the boiler?

Tom M.

This can stop air noise also.

Imagine this: multiple 3/4" zones piped into top of 1 1/4" manifold. Zone 1 is running. Velocity is reduced as flow enters larger diameter pipe. Air separates and bubbles up into zone 2 up through first floor closet into second floor baseboard (pretty loud at 2AM). The solution: an underslung return traps air in the manifold until it is absorbed by cooling water or carried into the boiler by greater flow when multiple zones are running.

bob_50

Holby anecdote

inherited the service on a bunch of apartment bldgs with holby valves and had troubles with ghost flow. Called holby and talked to an eng. He said " are they piped exactly like the diagram" i said well...He said I'll send a rep out to look at them but if that trap is 25" the first thing is repipe. So I repiped exacty to dia. and guess what? The darn things worked perfect.

bob young

holby---they work

i consider a holby valve like a jenkens valve----a piece of jewelry. the heat sink was adapted by them about a million years ago.

clammy

Thermal trap

I started piping my boiler panels with each return having a thermal trap and i've yet to have a call related to thermal migration ,but i also used either a circ with a internal flow check or a regular taco or b&g flow check on the outlet of the pump and of course pumps on the supply i,ll attach a photo peace clammy

bob young

picture perfect pipefitting

THAT my friend is a work of art. the old time gasfitters would be proud. ever see a 1930's vintage bank of about a hundred 3/4 " gas lines going to separate apartments from individual meters ? .tight centers and exact offsets completely covering an apartment building bsaement ceiling. all pressure tested w/ mercury gauge.

Constantin

A work of art!

Let me second that! Between the mounting system, the obvious care and attention to detail, where should one begin to praise? The flanges with built-in drains are a great product, the many drains and full-port ball-valves you installed will make servicing this system a joy.

More importantly, the whole system ought to be incredibly rigid with all the clamps, supports, etc. you've used. Nothing should be able to wobble, vibrate, orotherwise detract from a virtually silent system. Even the second-to-last oil filter sits on a elevated track... The electrical work is also amazing, BTW.

Allow me some questions...

• Do you prefer the fields RC barometric damper over the M model? I'm still trying to determine whether the M as installed is right in my system.
  
• Is that a LWCO at the end of the return header, close to the boiler?

Anyway, I hope you got heaps of praise and follow-on projects from this system, you certainly deserved it!

Constantin

What an elegant solution

Are those special 180° fittings for the pipe to return on itself like that? I like this solution a lot, along with the clamping and the Earthlee (?) headers you used to make the job very tidy.

Tom M.

Those are actually

3/4 x 1/8F x 3/4 tees with street 90's and 1/8" brass plugs. I don't know who makes the header tees but they say "EZ-HEADER" on them. I posted the picture as an example. It is from a customer's house (the one in my house was more hastily done and doesn't look as good).

[Deleted User]

Allow me to turn on the lights for you...

Great job clammy. You've come a long ways my friend from when you first showed up here at the Wall. Keep up the great work.

ME

clammy

Thanks

Thanks for all the kind words .I'm finally at 42 going out on my own but i've found that i'm pricing against alot of hacks and i will not lower the quality and engeernering that i put into my jobs .I'm working with a plumber friend doing heating and some dwv but somethings and ways he does things are not even close to my standards but it's his name on the door so what he says goes and i just do it and when it doesn't work i fix it i get paid either way.On the heating front it's starting to pick up but on a/c i can't compete with bigger companies and plumbers who are putting 6 foot extended pleums and 1000 ft of flex at least i know why i don't get the jobs and i accept it and just keep looking at the jobs giving qoutes and wait for people who know and want quality .Thanks again to everyone it's all you guys that always remind me not to lower my standards and quality of work just for the quick buck and hope that it works and that i sdon't have to service it peace clammy