Replacing Ceiling mounted Thrush Compression Tank

WMno57

Air injection is managed by the Air Volume Control (AVC), Snifter valve, and breather ports(???) in the vertical feeder pipe in the well shaft.

Or you can do what I did and have none of the above.

I pre-charge my tank to 38 psi, (40-60 welltrol) so before water-logging, my plain tank is equal to the same size bladder tank.

I did it because I have a lot of iron in my water. The tank does last longer. It is a vacation house and I drain it, which is more stress on a bladder.

I don't like the idea of having my son's maintain it. I can't sell it that way, so it will soon be changed to a bladder. My current house has an under-sized bladder tank. Another project. I'm on the fence as to whether that tank will be a bladder or not.

Compressed air is dangerous. Never repair an air compressor tank. Use the OEM specified oil in a compressor. Truck, and even car tires have maimed and killed. Damaged tires and wheels should be scrapped. Multi piece wheels should be aired up in a cage. Do not use ether to seat tire beads. Do not use PVC for air lines. Never weld a wheel with a mounted tire.

Never get comfortable around compressed air.

JUGHNE

I am familiar with all the precautions with compressor air that you have mentioned with one exception.
Could you expound on the detergent oil use?

WMno57

First, I hope people don't read my posts and decide to go off and do dumb things. My air over water well tank is a dumb thing. I don't wish to encourage that. If you enjoy DIY projects, slow down, and think things through.

Going off memory here, think I have it right:

There was an air compressor tank failure at a car wash (California?) with a fatality. This compressor was run hot and heavy, and may have had blowby. The investigation found evidence of combustion on the tank shards. The theory is there was a combustible mix of oil mist in the tank, one of the hot valve deposits fell off and ignited the mixture in the tank.

The explosion caused the tank failure.

Sounds a little far fetched, and I think it would be very difficult to reproduce in a home shop.

Valve deposits do cause other less catastrophic problems. Non detergent oil is available, and is also recommended for old B&G circ pumps. There are also some very good air compressor oils now. My Estate sale air compressors get an oil change when I get them. They are probably overdue, and now I know what's in there.

WMno57

https://www.cdc.gov/niosh/face/stateface/ca/05ca010.html

"The test results of a failure analysis laboratory concluded there were products of combustion in the air tank that were most likely caused by the wrong viscosity of oil being used in the air compressor. The oil in an air compressor serves two purposes. First is to lubricate the compressor as it operates and second, to help cool the compressor and the compressed air it produces. The oil must be of a certain type and viscosity in order to produce the desired results. Manufacturers of air tanks and compressors usually recommended what type of oil to be used in their product. When OEM oil is not used, studies have shown that the oil may leak past the seals and gaskets and form carbon deposits in the supply line. As the diameter of the supply line decreases because of the carbon deposits, the compressed air, which is already at a high temperature, will increase even more, to the point where it might be possible to ignite the carbon deposits. If this should happen, and a piece of ignited carbon gets into the air tank, it could cause an internal explosion. "

This seems to point to deposits in the supply line. Maybe my concern about the reed valves is that valve deposits cause valve problems.

Abuse of duty cycle, and 23 years of use in a car wash. That's a lot of hours. Think I will pull and inspect some supply lines.

JUGHNE

That must have been years ago, I can't imagine there being anything remaining in California that is dangerous to anyone anymore....safest place in the world....and they are trying to drag the rest of us to that Nirvania place.

Solid_Fuel_Man

The state of Kalifornia knows this substance to cause cancer. My state is too dumb to read this label.....or this doesnt cause cancer in my state! Win win. 

WMno57

Apparently my memory of reading the report years ago, and the actual report do not jibe. I will do more research on the oil question.

Most air compressor tank failures are due to corrosion.

Back to boilers:

The higher the pressure, the more the risk.

The car wash compressor was two stage and running up to 150psi. Just checked my boiler. 14 psi of hydrostatic pressure. Water does not expand when containment is lost. A corrosion failure in a heating system might cause a few things to get wet. No blast damage.

Solid_Fuel_Man

Correct, the max pressure any residential boiler can get is 30psi....assuming the relief valve works. 

Only compressible fluid is the air in your tank. 

I know several wood heat guys who use old propane tanks as pressurized water heat storage, as well as compression tanks. A 100 pound LP tank would make a good compression tank if you were so inclined. 

WMno57

JUGHNE said:

I am familiar with all the precautions with compressor air that you have mentioned with one exception.
Could you expound on the detergent oil use?

I stand corrected. Detergent oil is OK for some air compressor pumps, but not others, and may have nothing to do with the California Incident. You guys make my brain hurt. I have learned so much lurking for two years. Now that I post, you are making me learn more. Sorry for the confusion.

OSHA makes no mention of detergents and points to wrong viscosity as the cause.
https://www.cdc.gov/niosh/face/stateface/ca/05ca010.html

Campbell Hausfeld makes no mention of detergents and says use Mobil 1 10w-30 synthetic. M1 10w30 has detergents, but no viscosity index improvers.
https://www.campbellhausfeld.com/how-to-change-air-compressor-oil.html

Saylor Beall says "For 700 and 9000 series pumps use a 30# non-detergent type"
https://www.saylor-beall.com/faq/

Quincy makes no mention of detergent, for or against. If it was the cause of the California incident, one would think they would say something.
https://www.quincycompressor.com/products/genuine-quincy-compressor-parts-and-oil/oil/

WMno57

Project update with pictures:

I hope everyone had a good weekend. Mine was pretty good;
Beer from Wisconsin, watched the Bears lose, thread drift on the net, and I took a break from my heating woes. I did call my contractor Saturday afternoon, and left him a voice mail.

Now back to work.

Monday's task was tidy up the jobsite:

Jamie Hall

The water system in Cedric's home used to serve a dairy farm and three other properties, as well as Cedric's. It started out (once running water was installed!) with a large -- 5000 gallon more or less -- elevated storage tank. A maintenance headache. Then for almost 50 years it had a 2,000 gallon underground hydropneumatic tank with the same kind of controls that @JUGHNE mentions. It's still there, but out of service. The dairy farm is gone and the services to the other three houses as well, and now the well pump is controlled by three of the largest Well-X-Trols made. They've lasted pretty well -- one of them has died, after 30 years. The other two are still going.

JUGHNE

Is it looking like you have to drain the system to lower the 3/4" pipe to the bottom of the new tank, rather then the end port on the existing? (to get the rise up to the tank so the air will migrate upward).
IIRC, you had original air bleeders on the CI rads.....is it a good time to change them?

WMno57

My experienced contractor and his young able assistant are making working noises in the basement as I type. I'm very glad they are here. My old elbow is hurting from tidying up yesterday, but i sucked it up and pre-wrote part of the check. I may need to learn how to write left handed, or have the computer do it.

I'm going to do a left handed 12 oz curl when this is over.

I try to stay out of their hair. I did have a conversation with them about air migration, and specifically how I want the pipes run. Trust, but verify.

The air bleeders are old, but they are all working well. I think they plan to work on a wet system.

Today's project scope is to get this through the winter. Maybe big changes next summer.

Stay tuned for pictures.

WMno57

They had to make a quick trip back to their shop. I know you are all wanting to know what wasn't on their van. If I told you it would be a violation of the commonly understood confidentiality agreement.

While they were at back at the shop I snapped some Work in process pictures of "how the sausage is made".

WMno57

Done!

Get the right parts.
Get the right people.
Do not allow scope changes. Push those to Phase Two.
Communicate with Stakeholders.
Have Contingency Plans.
Under Promise. Over Deliver.
On Time, and Under Budget!

It's 5 o'clock somewhere.

JUGHNE

So can you pull the old vac breaker plug and show us the internals of it?

WMno57

Presenting the Thrush Vacuum Breaker:

Note the toothpick and thread depth in the last picture. The toothpick is in a hole that connects to the vertical tube. Unscrewing the TVB part way exposes the hole and air is sucked in, traveling thru the tube to the top of the tank.

The tank itself is very simple. Just a 1/4 NPT port. The TVB could be replaced with a 1/4 NPT pipe plug, but you would lose the fast draining ability.

JUGHNE

The B & G Airtrol tank fitting gives that advantage also.
It has 2 tubes that go up into the tank, the larger one is to direct the air up that is collected by the lower part of the device.
The smaller inner tube is your water level indicator, it is so small that it can be only cleaned with the wire used on marker flags.
There is a small plug on the end of the small tube that you open to drain down until you get air only. Works pretty good.

leonz

I am very happy using the B+G(Wessels tank) 15 gallon compression tank with the B+G airtrol valve and B+G Internal Air Separator for my coal stoker boiler. My system pressure is bare 2PSIG with 225 feet of 3/4 inch fin tube baseboard which I hate as I wish I had cast iron hot water radiators for their thermal mass.

Big Ed_4

Gee , I would never like to go back to steel ceiling tanks .. I drain too many of them .. Today it would take me 6 trips out to the street rather than 3 ... Did you ever empty the bucket in to a sink that was disconnected ? Bringing that last muddy bucket though the living room and bunk into a piece of furniture ? Blowing into the hose to break the vacuum ... They don't make them like they use to ... I say Thank You God

P.S. Heads up those Economite motors dried up from stock a few years ago ..

WMno57

@leonz Not a lot of tank manufacturers out there. And if you want a galvanized tank ............

"In the late 1970’s, about ten galvanized tank manufacturers existed in the United States. In 1978 with a new management and a new sales policy, Quick Tanks focused on this core product line, and by the mid 1990’s was the only galvanized tank manufacturer left in North America."
https://quicktanks.com/about-us/

I suspect the plain steel tank industry has also consolidated. I know of Quality, Wessels, and Quick. There may be a few others.

http://www.qualitytanksinc.com/
https://www.westank.com/
https://quicktanks.com/

I've found some nice looking cast iron radiators, by using the search term "boiler" in "All sections" of Craigslist.

@Big Ed_4 You bring up some of the reasons why these are obsolete. My contractor also warned me about the unavailability of the Economite. Next year I will start a new thread in the Gas Heating section. I'm hoping to learn more about my burner options.