Ancient Air Valve

fjcruiser105

This is the air valve at the end of my main. I took it off and am going to replace it with a Gorton #1 as advised by Rod( thanks again). Just for knowledge of home, does anyone have info on it. The top is marked THE TRANE CO. LACROSSE, WIS.

crash2009

Trane # 2

see page 3

fjcruiser105

Trane # 2 quick vent

is the vent I have. Since it is not clogged when I blow through it and shuts as soon as I inhale, does that mean this valve is stiil good? Should I leave it, or possibly add the Gorton No.1  as well with an antler.

nicholas bonham-carter

trane vacuum valve

if it closes as you inhale, it will not relieve the vacuum at the end of a cycle, and your vents will be very noisy.

take this oportunity to replace it with a gorton #2.

if this system was originally a vapor system, you might want to put on a vaporstat, and cut the pressure to 8 ounces for maximum fuel savings.--nbc

later edit---

that trane vent is about two and a half times the capacity of a gorton #1, according to the gill/pajek chart [available from the shop here].

crash2009

I don't really know

if its still good or not.  It is listed as obsolete on the venting capacity chart.  The rating is .780 cfm @ 1oz,,,the Gorton #1 is rated .330 cfm @ 1oz.  Gorton #2 is rated  1.100 cfm @ 1oz

fjcruiser105

You mentioned

that the vents will be noisy. I have a two pipe system with steam traps. Don't know if that makes a difference.....or should I just change it?

crash2009

If you go with

the Gorton 2, it has half inch threads. you will need a reducer to put it in a three quarter inch hole. 

Rod

orifices?

fjcruiser-   I just had a thought. Is there a chance that your radiator inlet valves have orifices?

Trane, from what I've read, was big on them. If after you get your siamesed dry return split, you still have some under preforming radiators, you might want to check that radiator for an orifice and see if the orifice is partially blocked with dirt, rust etc.

Vents- I mentioned this before -  I think you can get away okay with one Gorton #1 on each main but may want to go to multiple Gorton #1s or even a Gorton #2 on each of the Dry Returns as these have to handle the air volume of all the radiators.

- Rod

Dave in QCA

Where was this vent?

I was just looking at your pics on the original post.  Is this vent the one that we see in the return lines just above the boiler?  If not, are there vents at the ends of the steam mains?  Sometimes the steam mains are vented with a crossover trap to the dry return on a 2 pipe system. 

Just asking so that we don't throw you confusing iadvice. 

Rod

System

Hi Dave-

This is the system:

1, 2 pipe system

2. Two parallel mains each dropping into Wet Return (below waterline)

3.  Each main has its own vent at the drip end.

4. Returns are now joined above the waterline.

5. Both returns use the one vent.

6. Vents are old and possibly non functional



Solution:

1 Split the returns- each to have its own drop to the wet return

2. Each return will have its own vent

3. Renew the vents on each main.

- Rod

Dave in QCA

My Apologies for jumping late..

Rod,  I have gone back and thoroughly read the previous threads on this post.  I've got a clear picture of the system.  Sounds like the end of main venting has been addressed.  I agree with you that the wet returns from the end of main drip legs are too small, but it served well as an emergency repair.

However, I am going to disagree with your advice to separate the dry returns.  Here is why.

While it will cause no harm, it is not necessary.   It is completely normal for the condensate return piping to all converge and vent through one common vent.  In a pumped system, it is through the vent pipe on the condensate receiver tank.  In a gravity system, an opening to the atmosphere must be provided.  It could just as easily be an open pipe, but since this system originally operated in vacuum, it needed the check function of the Trane Quick Vent.  Also, using a vent device will prevent steam from being discharged directly into the boiler room if a radiator trap would fail.  However, in a pumped system, live steam coming from the condensate tank is one of the visual ques that you have a trap problem.  Since steam will never reach the return vent, it will never close, and both return lines should vent just fine.

Also, remember the old adage that you want to vent the mains fast and the radiators slow.  I am battling in my own 2-pipe system, the fact that the radiator traps have HUGE venting capacities, and you cannot adjust them.  I have found it necessary restrict the common venting of the return piping in order to balance the system.  Remember that once the mains are vented and steam is entering the radiators, the radiators begin condensing a very large portion of the steam that is being generated, and thus the CFM of air that is being vented, after the mains and risers have been vented, drops way down.

All that being said, splitting the dry condensate returns will not cause a problem, it just is not necessary.

OK, Now I have just finished going back to the February post on this same system and realize that there is a venting problem with one radiator.  It really does sound like a pitch issue on the return piping coming from that radiator.  The thread seems to jump from this issue last February to the current 1 vs. 2 pipe riser on a boiler near piping issue of the current thread. 

.

OK, I know that there is nothing more irritating that someone walking into the room near the end of a very long conversation and saying, "Huh?  What did you say?"  

So, I'll duck when you throw the pipe wrench at me from across the room, and sheepishly smile because I know I had it coming!

Rod

Combined Returns

Hi Dave - LOL -Large Pipe wrench coming your way! Actually I completely agree with you. In theory you shouldn't need to split the returns and in a well engineered system with big piping, combining the returns should work fine.

With the caveat that I'm an amateur at this, I think when you get down to home systems with undersized piping, many elbows, bull headed tees etc. there are circumstances when you run into trouble.by not separating the returns.  On the problem systems with combined returns that I have worked on, my feeling was there existed what I would call "an imbalance" between the returns with one dominating the other for venting capacity and condensate flow, which resulted in the performance of the less dominant lagging.

With the returns being connected near the boiler I think it makes sense to make a slight modification and separate them giving each its own drop to the wet return and each its own vent. That way each main (and return) is independent, there are no restrictions in the piping (two coming into one), condensate steams don't collide, and no competition for the vent. Also there is no cross feeding to the opposite main if a trap on one main malfunctions (and it makes the search for the bad trap easier!).

On this system I'm not too happy about using the baseboard as a wet return as I think in the long run it will cause problems. As the mains go in opposite directions I'm assuming each has its own baseboard return and if they are both independently connected to the wet return, that you may get away with them being undersized. As you say this is a good emergency fix but may need to be reconsidered  when the weather gets warm again.

 Your large trap size is an interesting situation. It sounds like a good application for orifices though with orifices you then wonder - "why do I need traps?".  I have often thought the "dream system" would be a two pipe system with adjustable orifice Mepco valves on the radiators.

Just my 2 cents worth,

- Rod