tenant elbow rust

rabbitsfoot

I'm a tenant. I saw this go off the other day at 30psi  . The man who came to fix it said it was the compression tank...I think he drained it or filled it with air...said he didn't have replacement prv and needed to get one...said the system was put in about 3 1/2 years ago. I think it looks unsafe though this the first radiator furnace I've seen close up.  How old can that valve be? Very new rust streak? I'm not going to get any closer than my camera . In the comments section of a you tube video by someone named Steven Lavimoniere ("Boiler Leaking Water Out Relief Valve"), a Michael Geary mentions his Weil McLain's deteriorating prv elbow and his concerns relating to possible boiler corrosion nearby-no one in those comments answered him though. I wondered if anybody here could.     So the compression tank was fixed, I guess, and since the valve was also beading/sweating water out at the threads, it must have been tightened because it's been dry since the fix 30 days ago. worried though...Just saw the underside of the blower in this picture-and the little rust spot...that valve...

Jamie Hall

no picture...

pecmsg

From here without any pics it sounds like the relief valve did its job and the issue was the Compression tenk. (were talking about a tank mounted on the ceiling)
As far as the relief valve its his decision if it can be pulled and reinstalled at the time he was there or if a replacement is in fact needed.

rabbitsfoot

rabbitsfoot

pictures!

PC7060

Thanks. one or two a bit further back would be helpful too.

EdTheHeaterMan

That elbow may only be 3 or 4 years old. It is as old as the boiler. The boiler comes with it already installed in most cases. There are many, many years of life left in that fitting as long as the relief valve does not leak on it anymore. There should be a "safety tube" attached to the outlet of the relief valve to direct any discharge to a safe location near the floor. This will keep water from getting on the elbow causing more rust. A little elbow grease with a wire brush and the elbow will look like new. (one of the common uses for "Elbow Grease")

JUGHNE

It looks like the drop pipe for the relief valve is laying on the floor. (picture with switch and pump).
Maybe was not screwed in and the valve dribbled for a long time rusting the elbow.

rabbitsfoot

pecmsg

Shouldn’t that be a P T relief?

ChrisJ

pecmsg said:

Shouldn’t that be a P T relief?

I've never seen a heating boiler with a T&P.
I've always wondered why....

mattmia2

That automatic air vent on the cast iron fitting above the right side of the boiler(air scoop) is not correct if the system has a conventional compression tank type expansion tank. The system should have an air fitting that moves any air in the system back to the tank and no automatic vents. That automatic vent will cause the expansion tank to become waterlogged again.

rabbitsfoot

to mattmia: you mean this thing?

mattmia2

Yeah, that is the air scoop. It should be a different fitting or the tank should at least connect to the top of it instead of the bottom. The way it is connected now any air that migrates out of the compression tank is going to be removed by the automatic vent instead of returning to the tank.

rabbitsfoot

How long might it take for all the air to migrate out of the tank, or for the tank to become waterlogged, if there's any difference?

JUGHNE

I have wondered about a T&P on water boilers, but have never seen one with the right parameters. Needs to be 30PSI for the pressure part and what temp?-- 200-210 degrees.

There have been some boiler installed T&P shown on the wall here, they were water heater tank rated. 125-150 PSI and 210 degrees.
Unknowing home owner changed his dripper, really fixed it well as it never opened again.
I guess we just have to rely upon electro mechanical high temp limit switches for the over temp protection.

JUGHNE

rabbitsfoot; I service a system that has an 80 gal compression tank.
It had an auto air vent on the piping, the air was being lost in the tank in about one season. Learned about the system more and removed the air vent.
Then air would last about 2 seasons.
Then learned the the convenient sight glass would loose air on the top fitting, then repacked that valve.....the air has been good for at least 4 years now.
Again can be viewed by the non leaking sight glass.

You can disable that vent by tightening the Schrader cap down tight.

PC7060

My old overhead compression tank was fed by a Thrush valve which directed all air into tank as @mattmia2 said. 

You can see the tank in background in the second picture. 

Why not just put a #30 Amtrol in and keep the air scoop. Seems much easier. 

rabbitsfoot

to JUGHNE : the system here has 11 big old radiators on two floors (none in attic). The tank is a 45gal "Jacuzz".  Is "80 gallons" bigger for a larger system?

JUGHNE

The size of the tank is determined by the volume of water in the system and the temp it runs at, but mainly the gallons involved.
The 80 gal was in a 10,000 sq ft school built in 1961, just to point out that the air charge can be retained a long time if the system is tight and not losing air.

rabbitsfoot

are these old tanks usually being replaced with the bladder tanks by preference?

JUGHNE

Yes, most often they are replaced with bladder type expansion tank.
Usually a better air venter in installed at that time.
But the bladder tank would have to be changed in less than 10 years because of being water logged.
Your existing tank is probably 50-60 years old.
Also in your case the next size of tank up would be needed because of water volume.

For being the tenant you have quite an interest in all this.
Do you pay your own heating bill directly to the gas Co.?

rabbitsfoot

No. I just pay an all-inclusive flat rate. Nice house, nice neighborhood, nice guests. It's just the looks of that scaling elbow close to the boiler and what looks like a safety tube just below it that got me started. The threads look okay so I guess it wasn't blown off...but since I first moved in I did bleed the radiators with a key from the first floor up-shortly after another tenant bled them for the year, thinking it would get the last little bit of air out and make things warmer. after I later saw the valve spew I shut off the boiler switch seen on the picture. The guy who works on this didn't really like those last two things. Really, I'd rather not touch it.

rabbitsfoot