Diaphragm expansion tank, ins and outs

Derheatmeister

hot_rod said:

Jamie Hall said:

Filling the tires with nitrogen is one of the most fascinating current scams I have run into. Charge 20 bucks per tire (or more) for nitrogen (which is going to cost you maybe one) when you can use your compressor for pretty much free...

Um... right..

Mind you now, I admire German engineering. Mostly wonderful stuff. But working on German machinery when it goes amiss is an absolute nightmare...

On the chemical side, the small amount of oxygen in the air used for a tire or a precharge will be reacted -- to the extent it is going to -- within minutes. Tires fail for two primary reasons -- the wrong air pressure (either too low, very common, or too high -- I have seen that a few times -- or exposure to sunlight.

Supposedly the nitrogen doesn’t leak out as fast as compressed air, 40% slower in this opinion.
5 bucks per tire around here. Although they claim to include it when you buy 4 tires at Costco
My truck tires run 80psi, it’s worth the extra 5 bucks to me. Or free😗

Because it cost me 2 bucks i also fill my tires with "Stickstoff"/Nitrogen

Derheatmeister

Derheatmeister said:

hot_rod said:

Jamie Hall said:

Filling the tires with nitrogen is one of the most fascinating current scams I have run into. Charge 20 bucks per tire (or more) for nitrogen (which is going to cost you maybe one) when you can use your compressor for pretty much free...

Um... right..

Mind you now, I admire German engineering. Mostly wonderful stuff. But working on German machinery when it goes amiss is an absolute nightmare...

On the chemical side, the small amount of oxygen in the air used for a tire or a precharge will be reacted -- to the extent it is going to -- within minutes. Tires fail for two primary reasons -- the wrong air pressure (either too low, very common, or too high -- I have seen that a few times -- or exposure to sunlight.

Supposedly the nitrogen doesn’t leak out as fast as compressed air, 40% slower in this opinion.
5 bucks per tire around here. Although they claim to include it when you buy 4 tires at Costco
My truck tires run 80psi, it’s worth the extra 5 bucks to me. Or free😗

Because it cost me 2 bucks i also fill my tires with "Stickstoff"/Nitrogen

Jamie Hall

The amount of water which passes from compression tank into (or out of) the rest of the system in minute -- there is no circulation through the tank. Doesn't seem to be a problem.

And yes, I've heard that nitrogen doesn't leak out of a tire as fast as air. That may be so. I wouldn't know, as the only truck tire I've had in recent years in regular service leaks through a faulty valve which I haven't fixed yet. It loses about 20 pounds a month (from 50 to 30) if I let it. The other three (one 30, two 80s) don't lose air at all. My classic truck does have a tire which leaks at the rim -- again, I haven't fixed it as it takes about 3 months to go flat, and I leave the tires at 5 psi except when I take her out for a show.

Considering that air is 80% nitrogen anyway, it's kind of hard to come up with a mechanism to account for the claim...

hot_rod

Using the math, the compression tanks tend to be quite a bit larger.

Derheatmeister

Just a quick update: My brother's Expansion tank was installed in 1992 and in failed in approx. 2018.
In my book that is 26 years ...Again this "MAG" as the germans call them was filled with "Stickstoff"/Nitrogen..
The proof is in the Pudding

leonz

hot_rod said:

leonz said:

The dead men did things simply making use of simple physics using hydrodynamics and temperature rise to move heat from a to z and back to a.

An open to air saddle tank does not take up that much room at all, in fact the one that was in this house was smaller in length than the 15 gallon steel compression tank I have now.

Diaphram tanks were an outgrowth/need of the levittown tract houses that covered all that beautiful farm land on Long Island that were built as small slab on grade kit houses with copper pipe in the floors for hot water heat.

These homes did not have attics for open to air expansion tanks or basements for a boiler installation using gravity hot water heat or a circulator.

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Open to atmosphere tanks allow constant O2 into the system, how could it not?
The tank needs to be sized to handle the expansion across the temperature increase

Closed pressurized compression tanks are a different animal. The water in those systems eventually becomes oxygen starved.

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If a system is cavitating, yes there will be microbubbles in the system but the vertical or saddle open to atmosphere tanks only have atmosperic air above the water line and any air that is in the steel compression tank systems eventually rises and escapes into the air blanket above the water line in the steel compression tank and any rust occurs only at the water line from what I remember.

Oxygen at one atmosphere PSIG has to be consumed by combustion or displaced by another gas like carbon monoxide or carbon dioxide to be diluted from what I remember of my chemistry and mine rescue training.

leonz

hot_rod said:

Using the math, the compression tanks tend to be quite a bit larger.

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Hello Bob,

With my residential installation I have a 15 gallon Wessels/B+G steel compression tank.

Being a novice at this, I should have used and reinstalled a 15 gallon open to air steel saddle tank with tube sight gauge and a screened air vent as was installed in my original heating system with the AVCO LYCOMING boiler my home had when I bought the place in 1978.

The Amtrol sheets you were so kind in providing from 1977 I believe should be updated as water logging would only occur if there is no back flow preventer, globe valve or ball valve stopping more water to enter and on page A2-9 based on my closed system.

Granted the drawing on page A2-9 is simply laid out but leaves much to be desired and would cause a good plumber fits in my opinion as a novice.

If the top tapping in the saddle tank des not have a street ell with a pipe nipple used as a venting pipe coming off the top tapping with a globe valve and pipe cap to vent excess air quickly when filling the system while leaving the air drain fitting open on the airtrol valve at the same time it would be more difficult to bleed air out of the system.

Mr. Holohans Pump Module design drawings simplify the removal of trapped air in a hydronic heating system immensely for a plumber or home owner.

The Bell+Gossett literature for installation of an Internal Air Separator and Steel Compression Tank
that I used to create my pump module per Mr. Holohans drawings in Pumping Away and Classic Hydronics in comparison to the Amtrol drawings on page A2-9 from 1977 is massively different from my installation and leaves a great deal to be desired as there is no gradual slope of pipe coming from the side tapping of the boiler to reach the air separator to allow it to work well with either an air scoop or IAS. The drawings are simply laid out for reference but should be redrawn.

Air like water is lazy and will go where it wants, when it wants, and it has to be controlled. Mr. Holohans Statement "Be The Ball" rolling down the pipe is well said in this case.

WMno57

My Thrush compression tank was good for 70 years until it leaked. Replaced it with another compression tank from www.qualitytanksinc.com. Great people and they will sell direct to homeowners.

hot_rod

leonz said:

Using the math, the compression tanks tend to be quite a bit larger.

---------------------------------------------------------------------------------------- Hello Bob, With my residential installation I have a 15 gallon Wessels/B+G steel compression tank. Being a novice at this, I should have used and reinstalled a 15 gallon open to air steel saddle tank with tube sight gauge and a screened air vent as was installed in my original heating system with the AVCO LYCOMING boiler my home had when I bought the place in 1978. The Amtrol sheets you were so kind in providing from 1977 I believe should be updated as water logging would only occur if there is no back flow preventer, globe valve or ball valve stopping more water to enter and on page A2-9 based on my closed system. Granted the drawing on page A2-9 is simply laid out but leaves much to be desired and would cause a good plumber fits in my opinion as a novice. If the top tapping in the saddle tank des not have a street ell with a pipe nipple used as a venting pipe coming off the top tapping with a globe valve and pipe cap to vent excess air quickly when filling the system while leaving the air drain fitting open on the airtrol valve at the same time it would be more difficult to bleed air out of the system. Mr. Holohans Pump Module design drawings simplify the removal of trapped air in a hydronic heating system immensely for a plumber or home owner. The Bell+Gossett literature for installation of an Internal Air Separator and Steel Compression Tank that I used to create my pump module per Mr. Holohans drawings in Pumping Away and Classic Hydronics in comparison to the Amtrol drawings on page A2-9 from 1977 is massively different from my installation and leaves a great deal to be desired as there is no gradual slope of pipe coming from the side tapping of the boiler to reach the air separator to allow it to work well with either an air scoop or IAS. The drawings are simply laid out for reference but should be redrawn. Air like water is lazy and will go where it wants, when it wants, and it has to be controlled. Mr. Holohans Statement "Be The Ball" rolling down the pipe is well said in this case.

My Amtrol book is a 2011 version, perhaps there is an updated version at their site. I think 1977?was the first printing?


Maybe send them some suggested piping improvements for the next reprint

Probably on larger engineered jobs the piping drawing is in the M sheets, as per the designer’s requirements?