AL29-4C piping MK

Mike Kraft

When piping for vent termination we install condensate tees.My question is have any of you come across any drip loops that do not seal with condensate?I have of recent.

The combustion experts at this site and Oil Tech Talk have been assisting me in furthering my education in this weak area of my profession.Over the last several years I have been attending various oil combustion classes.My attention has been primarily on oil.My installs are left to the fuel companies.I do reckognize this as a very bad habit.For many many reasons.

My concerns have grown and my awareness has become more attentive.My questions are :

How do you test for joint leaks on an AL29-4C install.

Why would a looped silicone "trap" not fill with condensate.Should this tubing be primed?As of recent silicone tubing is the reccomended material.Over the years standard issue has been clear vinyl tube.

Venting of gas appliances seems to be a forever changing world.Methods and materials..............just think of how many systems are wrong that were once right.

cheese

[Deleted User]

They DO need priming

Otherwise, the fan blows the water vapor right through them.

They also need checking. They can dry up, and they can be blown empty by a hard ignition. Then they vent into the space until they are reprimed.

There's always something to watch out for....

Noel

Unknown

Mike it was good talking

to you today.

to answer your questions:

The AL29-4C can be tested with the burner off and the combustion air blower running take regular every day dish washing liquid and dilute with water and soap the joints if they bubble they need sealed. That is obviously done on the pressure side of the blower + pressure.

Noel answered the one about priming. As for tubing different tubings have been a problem over the years, I do not think anyone has the real answer to which tubing is going to work best. The condensate is basically carbonic acid and tends to clean anything it runs through and clean and clean until it affects the tubing.

The venting question is one that remains a study as time goes on. The National Fuel Gas Code requirements for Natural Draft and some fan assisted applications is pretty straight forward. It is just getting used to all the alternatives and methods. I have broken venting down into three categories of discussion.

1. Natural Draft Convential Venting

2. Venting - Mechanical Draft Systems

3. Venting - Special Venting Systems (Category IV) Condensing

I have three seperate manuals on each subject that will tell you how complex it is.

H. Green

Tim - your advise is good, but, if you use soap and/or soapy water to identify leaks you run the significant risk of not being able to get a good seal in your repair. The silicones in our non-gasketed products will not adhere to a soapy surface. This is why we include alcohol wipes with our vent parts - to assure a clean, dry, bare surface.

Unknown

Interesting

I have heard that guys are using PVC cleaner to clean before using RTV, is that okay?

The soap and water thing is the only way I know to test for leaks. How do you recommend testing?

Mike Kraft

Back @ you Timmie!

So its as easy as soap water.Duh:)I tend to miss the forest for the trees.So if the soapy water challanges the repair of a leaking joint..........wouldnt the repair on the field installed silicone to disassemble the bad fit,clean and reapply or replace?If this is the tact then the soapy water would obviously be removed.I keep denatured alcohol on the truck and use it for joint cleaning prior to siliconing.

cheese

Steve Ebels

Cheese!!!!

We have had good success with a tubing called Tygon. Resists heat and corrosives well from what we've seen. I buy it from the small engine repair department in our store. They stock it for use as fuel line on chain saws, mowers, etc. Doesn't get crispy like vinyl tube does after a year or two. I've also used it to replace rotten rubber pressure switch tubes on boilers and furnaces. Don't know what the manufacturers think of this but it seems to hold up better than the crap installed at the factories. If'n you can't find it e-mail me with what size and how much and I'll send you some.

zeb_3

Question

How do you go about disassembly of an AL29-4c joint that has been sealed w/ RTV silicone?

Mike Kraft

Good ? Zeb

I had the pleasure of doing this a few weeks ago.Loosen clamp and work a fine bladed screwdriver to pop silicone.Then work it:)carefully.Rock-twist and shout!I opted to replace pipe with new gasketed type of AL29 piping.It just seems more bullet proof.

And Steve thanks........ifn' I needs it I'll let you know.I read in the instructions(Z-vent)that the "silicone"tubing is where its at.This now comes in a small zip lock baggie kit.Includes 8" of tube,hose clamp and a small zip tie.

cheese