Water logged in steel expansion tank


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Old 04-22-10, 01:00 PM
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Water logged in steel expansion tank

Hello I'm new and first time post questions in here.
I've been viewing & learning a lot in this forum about the expansion tank.

My parents' hot water heating syst. has been having problem with the relief valve this past winter. when cool down it read less than 7-8psi.. when I try to let water in to 15psi and bled air from the farthest/high radiators.. and when heat calls & it runs for 15-20 minutes then pressure gets higher till it pass 30psi then relief valve starts open and spit out some water..

From reading/learning in this forum, I know that the overhead steel expansion tank is water logged and need to re-pressurized it.

Syst.: Vaillant GA-92-100 series Gas fired cast iron hot water boiler. with Pump inside syst. Gauge/temp. also inside syt.

Radiators: 4pcs back zone, 1st & 2nd floor, main pipes 2"nps
(supply & return, parallel 3/4"nps feeding to each rad.)
4pcs front zone, 1st &2nd floor, main pipe 1-1/2"nps (supply & return, parallel 3/4"nps feeding to each rad.)

Expansion tank: steel and above the horizontal front zone return 1-1/2"nps main pipe.

Piping syst.: no any gate valve, no air-scoop, no reducer valve, no check valve .. only 1 globe valve from city water to feed the syst. (yes it was a lousy piping syst. that was installed by someheating comp. that my parents hired them to
replace the old system 4-5 year ago)

My plan are:
1. drain the syst. complete
2. the supply & return behind heater are 1-1/4"copper tube.
I'll cut and install 1-1/4" gate valves on both supply and return. For eliminating to drain the complete pipe syst. in future.
3. install a gate valve for the expansion tank between the tank and the main return line. for future easy draining/re-pressurize expansion tank.
4. The expansion tank is currently with 1"nps plug, and will be replaced by a globe or gate valve for future easy draining if water logged again.
5. Since I'll be cutting into the supply and return lines behind heater (1-1/4"copper tube), I may want to intall quality low pressure reading gauge for each line. Since Mr. NJ Trooper has been saying how distrust the pressure gauge on the syst.
6. I will also install a new replacement main water valve from
city water to feed the system in the return front zone 1-1/2"nps pipe.

Questions:

A. Currently the steel expansion tank is on the front zone return line and if this is correct ? or it should be on the return main pipe before it split in to front & back zone? or it should be locate on the supply line before split into front & back zones?
B. Since I'll cut into these pipes/tubes, should I install air-scoop ? and should I install pressure relieve valve ? and check valve ?

Please advise me if any faulty on my plan ? and if any recommendation.

Thank you for reading my lengthy post.

PAT-19380
 
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Old 04-22-10, 01:40 PM
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Can you post some pix on a freebie image hosting site, and link them here? I'm having a bit of trouble visualizing how your expansion tank is plumbed.

I would use ball valves rather than gate valves for this project.
 
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Old 04-22-10, 02:06 PM
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Water logged in steel expansion tank

Hello,
I am new and first time post in here.
I have been reading and learning a lot from this forum.

My parents hot water heating system have been having problems in this past winter. it is water logged and high presssure relief problem.

My parents had the new replacement system about 4-5 years ago. The heating company who did the job was very lousy.
they swap out the unit without putting any gate valve, no pressure reducer or check valve or any valves at all... not even replace the old leaking main 1/2" water valve into the system.

System: Vaillent GA-92-100 Gas fired cast iron hot water boiler. supply & return are 1-1/4"od copper, Taco pump inside return, pressure/temp/laditue gauge inside panel boiler.
Main piping: basement ceiling main horizontal supply and return, front & back zones.
Main pipes 1-1/2"nps (supply & return) front zone, parallel 1/2"nps feeding to 1st floor 2 radiators & 2nd floor 2 radiators.
Main pipes 2"nps (supply & return) back zone, parallel 1/2"nps feeding to 1st floor 2 rads, 2nd floor 2 rads.
Expansion tank: steel type overhead, Tee connected to main horizontal 1-1/2" return line. 1" or 3/4"nps square plug at teh far end bottom, No close valve from main return to expansion
tank.

My plan are:
1. drain the system complete thru the bottom 3/4"nps drain valve from the boiler.
2. Open the 3/4"nps square plug to drain the expansion tank
3. Expansion tank: install a gate valve between expansion tank to Main Return front zone line. and replace the 3/4"nps plug with a globe/gate valve. For future easy to empty & re-pressurize the expansion tank.
4. Tap in the copper 1-1/4"od tubes (supply & Return) behind the boiler to install a gate valve for each. To eliminate future complete draining the system for boiler service.
5. replacing old water main valve (feeding water into syst.)

Please advise me if my above plan is inline ? what else need to be consider or to do ?

Questions:
A. Is the expansion tank in the correct location at the main returning front zone line ?
B. Should I also intall an air-scoop in the main horizontal lines ? if so where is the proper location ?
C. Since I'll be cut/tap into those lines for gate valves, should I intalled and Tee with reducer for intalling additional quality / trusted low reading pressure gauge ? Because as Mr. NJ Trooper has been menstioning how distrust (lying) those pressure gauges in the orignal boilers !!
D. Should I also install a pressure reducer valve, right after the main water feeding valve ?

I'm greatly appreciate for any input/recommendation.

Thanks

PAT (the learning guy)
 
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Old 04-22-10, 02:44 PM
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Thanks for your quick reply Mike Speed 30.

I'm still struggling with how to use this post & reply in here.
think I posted this matter twice.. because my 1st post disappeared after I hit "submit"... there fore I have to re-write again and send.

Back to your questions "how your expansion tank is plumed"
- It's connected thru a reducer "TEE 1-1/2" x 1-1/2" x 3/4")
from the ceiling horizontal main returning line to the boiler in the front zone.

- For the pix. I'll have to go to my parents house this weekend
to take. May be a problem, since the boiler is located in a very tight space.. I'll try my best.

Again thanks for your speedy response.

PAT (the learning guy)
 
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Old 04-22-10, 04:02 PM
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Hello Pat, welcome to the forum. You will learn how to use very quickly I think. You will notice that I put both of your first post in this message thread... in case there is some difference between the two...

I think you should take this job in parts. One piece of the project at a time. I will agree that the expansion tank is probably waterlogged, so you should take care of this part first, and then think about how to do other things that might be needed.

Yes, I distrust gauges. But there is no real good reason to install extra gauges. The gauge on your boiler may be fine.

Let us wait and see what pictures you can offer us. Try to get the lighting good, the pictures in focus, and large enough for old people to see! (not MikeSpeed, he's a young man! I think!)

You can set up a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pictures there. Then, come back here and post a link to your public photo album and we will take a look and make our recommendations.
 
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Old 04-22-10, 06:06 PM
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Originally Posted by NJ Trooper View Post
Try to get the lighting good, the pictures in focus, and large enough for old people to see! (not MikeSpeed, he's a young man! I think!)
No, darn it! "Mike Speed 30" = Navy signalman lingo for "my speed is 30 knots." For a time, I was a "snipe," a Navy boiler and steam turbine operator. Now that my name's meaning is exposed, I may have to change it
 
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Old 04-22-10, 07:51 PM
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Pat, sorry for the bit of 'off topic' banter... we'll get back to ya as soon as we see the pics, guaranteed!

Hmmm... Mike, you might even know about "Bens best bent wire" then?

Since we're confessing, I'm not a cop!
 
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Old 04-22-10, 08:06 PM
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Here is a link that may help.
Expansion Tank Information
 
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Old 04-23-10, 10:01 AM
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http://i760.photobucket.com/albums/x...ler-pix-10.jpg

Thank you all,
I think above is link to my pictures.
Again this is my very first time that I use the Photobucket and do not know if i did it right !!

Thanks again for your speedy responses.

Pat (learning guy)
 
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Old 04-23-10, 10:44 AM
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The link just shows one photo, of the expansion tank. It would be helpful to show a few wide-angle shots that show how the whole thing fits together and hooks into the boiler. Where is the circulating pump located?

But anyway, I think we know enough now to understand why the conventional expansion tank is losing it's air cushion over time.

Ideally, for best performance, the tank should be connected, via a B&G airtrol boiler fitting (or equal) at the top (supply) of the boiler, where the water is hotest and where the solubility of the air is lowest.

Alternatively, you could leave the tank connected to the system return, but install an in-line air separator in the return line to feed air into the tank, for example: Inline Air Separator - Bell & Gossett world leader in supplying the Heating/Ventilating/Air Conditioning (HVAC) industry.

Otherwise, you're likely to have to drain the tank once or twice a year to restore the air charge. With the additional valving you propose, that might not be too troublesome, but if you're going to rip into the system piping anyway, I would add the in-line air separator and pipe up to the expansion tank.

You don't want an air eliminator vented to atmosphere anywhere on your system (for example, Maid-O-Mist). They only go with a bladder-type tank.

Another approach is to replace the conventional tank with a bladder-type tank (and add an air vent device).
 

Last edited by Mike Speed 30; 04-23-10 at 11:48 AM.
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Old 04-23-10, 12:17 PM
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boiler-pix-expansion-tank pictures by pat19380 - Photobucket

Thanks for links for exp.tank info. and air separators.

I'm still struggling how to post all 15+ photos. As i was able to upload all photos and not sure how to link all photos in same album !

Hope this times got more pictures per above photo link.

Thank you guys,

PatBeer 4U2
 
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Old 04-23-10, 03:33 PM
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OK, that link shows all 15 photos. The circulating pump's suction is on the expansion tank side - which is OK.

If it were me, I would add the valves to facilitate draining and venting the expansion tank and add a B&G in-line air separator. Use ball valves, not gate valves.

The option of going to a bladder-type tank would be OK, too, but you'd still want to add the valving. But a conventional expansion tank, once it's installed properly, should last a lifetime without maintenance - while a bladder tank will lose some air over time, due to diffusion through the rubber bladder, and will probably eventually develop an actual air leak.

My hunch is that the conventional expansion tank was set up properly when it was installed with the original boiler. Then the boiler was replaced by somebody who wasn't all that experienced with conventional tanks.
 

Last edited by Mike Speed 30; 04-23-10 at 04:50 PM.
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Old 04-24-10, 10:30 AM
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Diaphragm (bladder type) expansion tanks were invented for a reason. As someone that has seen a lot of "conventional" expansion tanks fail, usually rust through at the waterline, I recommend using a diaphragm tank. I have never seen a "conventional" tank that didn't require periodic servicing. Of course my experience is with commercial and industrial systems and not residential.
 
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Old 04-24-10, 12:05 PM
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Originally Posted by furd View Post
I recommend using a diaphragm tank.
OK, but we are talking about a system which already has an existing conventional tank installed.

My residential conventional tank was installed in 1953 and is still working perfectly. No leaks - and no service has ever been required. It does not ever require periodic draining and venting to recharge the air cushion. But if I'm curious, I can verify the level of the air cushion (by using the B&G Airtrol tank fitting) without draining anything.

If for some reason I had to replace my expansion tank, I might very well install a bladder type. Easier to install (one-man job) and more readily available - and likely cheaper, too (Extrol 60 costs $106 with free shipping). But I would miss the reliability of a conventional tank.
 
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Old 04-24-10, 02:23 PM
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Mike, in my thirty-plus years in the field your experience is the only one I have ever heard of that had that kind of success with a non-diaphragm expansion tank. The diaphragm tank I used when installing the heating system in my parents house in 1973 was still going strong when I sold the house after my mother's death in 1998.

When I was working I would use dry nitrogen for a cushion above the water and I also used corrosion inhibiting and oxygen scavenging chemicals in the system water. I still saw non-bladder tanks fail and almost always they failed from rust through at the maintained water line.
 
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Old 04-24-10, 03:19 PM
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Originally Posted by furd View Post
Mike, in my thirty-plus years in the field your experience is the only one I have ever heard of that had that kind of success with a non-diaphragm expansion tank.
Studying the photos posted by Pat suggest to me that his parents' house is probably 1950s vintage, or perhaps even a bit earlier. (Of course, the boiler and some piping have been replaced.)

Clues: Basement floor and wall concrete details; appearance of the floor joists; electrical wiring appearance (some rather old Romex - 2 conductor w/o ground); cast iron sewer pipe, threaded plus bell & spigot, and its condition; black heating pipe (some seems rather generously sized); galvanized steel water pipe (painted over); gas meter in the basement (not outside), etc.

Maybe Pat can tell us for sure the age of the house. (The expansion tank certainly looks original to me.)
 

Last edited by Mike Speed 30; 04-24-10 at 03:52 PM.
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Old 04-26-10, 07:52 AM
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Per Mike-Speed-30 quotes:
"OK, that link shows all 15 photos. The circulating pump's suction is on the expansion tank side - which is OK."

- I just wondering since the steel expansion tank is on the return side from only one zone (front zone) then joint by Tee from other (back zone) then back into the boiler !! If this is OK ?

Per Mike-Speed-30 quotes:
"If it were me, I would add the valves to facilitate draining and venting the expansion tank and add a B&G in-line air separator. Use ball valves, not gate valves."

- Yes I'll do as your recommedation.
Do I need to add a pressure regulate valve ?
Why is ball valves but not gate valves (Just want to learn) ?


Mike-Speed-30 quotes:
"May be Pat can tell us for sure the age of the house".

- House was orig. built in 1927.

Thanks for all you guys inputs.
Funny that I've always been wondering that Mr. NJ-Trooper is a cop & how he gets involve in such as these heating technical business !! then in one post that he told some lady that he was running a clown school (wondering if Mr. Trooper is serious) !!

PAt (learning guy)
 
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Old 04-26-10, 09:29 AM
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Originally Posted by Pat19380 View Post
I just wondering since the steel expansion tank is on the return side from only one zone (front zone) then joint by Tee from other (back zone) then back into the boiler !! If this is OK ?

Do I need to add a pressure regulate valve ?
Why is ball valves but not gate valves (Just want to learn) ?
Are you intending to add an in-line air separator? Theoretically, it might be better to have it on a main run, but I think if it's just on one zone, that should be OK. The air separator has to be on a horizontal run, and the piping from the air separator to the bottom of the expansion tank has to slope contiuously upward from the separator to the tank - so air bubbles will rise up to the tank.

If you choose to use a diaphram-type tank, then physical arrangements are a bit more flexible.

There needs to be a pressure reducing valve (a.k.a. automatic fill valve) between the city water and the boiler. Are you sure you don't have one? B&G, Taco, and Watts make them. If you are going to add a PRV, might as well add a Watts No. 9 backflow preventer - required in some jurisdictions.

Gate valves that aren't operated regularly have a tendency to get stuck in position due to deposits or corrosion. Regular (full-throat) ball valves are now used for many applications formerly served by gate valves. Ball valves have teflon seals and shut off better than gate valves. Ball valves go from full open to full shut in a quarter turn - gate valves take multiple turns, and there is stem packing that can develop leaks or get bound up. Ball valves are available with theaded or sweat connections and are usually bronze.

If you have two zones, do you have separate thermostats and zone valves for each zone - or are both zones either on or off together? Just wondering.

Conceptually, this project is relatively straightforward - but it's going to be a bear if you are inexperienced with plumbing. First of all, you'll need two 24" pipe wrenches, plus an 18" and a 14" - and some major arm muscles. (Don't bother with cheapo, imported wrenches - get name brand, such as Ridgid.) You'll have to run back and forth to a good hardware store to pick up various nipples, fittings, etc.

When you put the piping back together, install unions here and there - so you don't have to tear everything apart if there is a leak at a joint that you didn't get tightened sufficiently.

Looking at your photos again, I suspect that originally the house may have been set up for steam heat, and later converted to hot water. That's neither here nor there, though.
 

Last edited by Mike Speed 30; 04-26-10 at 09:45 AM.
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Old 04-26-10, 11:49 AM
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The air separator has to be on a horizontal run, and the piping from the air separator to the bottom of the expansion tank has to slope contiuously upward from the separator to the tank - so air bubbles will rise up to the tank.
The most common horizontal air separator is made for diaphragm tanks and has a 1/4 inch tapping in the upper side for an air vent. It is this tapping that would be used for the pipe to the expansion tank and in my opinion 1/4 inch is just too small. Maybe it can be drilled and tapped for 3/8 inch pipe but even that is on the small side.

Gate valves...
I agree with everything Mike has written here. For most residential uses the gate valve has been superseded by the ball valve. I personally don't like soldered in valves, especially for DIY because it is easy to overheat the valve when soldering.

Looking at your photos again, I suspect that originally the house may have been set up for steam heat, and later converted to hot water. That's neither here nor there, though.
Maybe but I doubt it. Gravity hot water would be my guess.

Really, all this work of installing an air separator and making major piping changes along with having to buy (or rent) a significant number of tools is just one more reason why I recommend going to a diaphragm expansion tank. Use a hack saw (or Sawsall with a metal-cutting blade) to cut loose the pipe to the existing tank and then connect the diaphragm tank in its place. You don't need anything larger than 1/2 inch pipe (or copper tubing) and you are done. I'd add a valve between the expansion tank and system to allow for easy replacement of the diaphragm tank if it should ever become necessary.
 
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Old 04-26-10, 02:14 PM
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All of B&G's inline air separators (except the very smallest) are tapped on top for a 3/4" air line to the expansion tank: http://www.bellgossett.com/literature/files/9.pdf A 3/4" line has proved satisfactory.

I agree that installing a bladder-type tank would be easier. I was thinking that for Pat to accomplish what he wanted, much of the new valving/piping might be needed either way, but now I see that is not so. Breaking those large, threaded connections would be a chore.
 
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Old 04-26-10, 02:24 PM
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I have to side with Mike Speed here. I despise diaphram tanks. I like the old steel tanks. Zero maintenance. The downside of these tanks is improper installation. Properly installed they require no maintenance. I know of plenty of them that were never or hardly ever drained. I say hardly ever drain because when you drain the system down you need to make sure the tanks is empty before refilling the system.
The IAS that Mike Speed was referring to has a 3/4" hole in the top of the air separator for the tank connection.
If the tanks rust out that means there is too much fresh water being added to the system. Metal will not rust with the absence of oxygen. Water includes oxygen, minerals and chemicals all which are also bad for the system.
Nobody maintains the diaphram tanks as they should be either. Who carries nitrogen to recharge them? How often is the charge checked? Who many have been installed to make them easy to check the air charge since the water pressure has to be dropped to "0"?
I like maintenance free. I had changed may out to diaphram tanks and when I learned more about the steel tanks we left them in and properly piped them. We even changed some back to the old steel type tanks. The key is proper installation and no automatic air vents. I have talked to many people who have never had the tanks drained.
In one of my past homes I was draining it every year due to pressure problems. The problem was worsened when I did the old Enertrol system (OD reset), if you remember this control it is reminding us how long we have been in this industry. With the heating and cooling of the water I drained the tank some times twice a year. I talked to an old timer, which now I am the old timer, and he asked if I had auto-vents. Of course I did. He suggested removing them and drain the tank the last time. I did change the piping slightly to improve the operation as per this link. In the next 7 years I lived there I never drained that tank again.
 
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Old 04-26-10, 03:08 PM
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Back on the issue of gate valves vs. ball valves (sorry to beat a dead horse).

You can tell at a glance whether a ball valve is open or shut by the position of the handle. Not so with a gate valve. (A rather minor point, I would admit.)

Also, a gate valve has a packing and packing nut through which the stem has to be turned multiple rotations between full open and shut. Eventually, the stem packing may leak and you'll have to hope the backseat holds. A ball valve has a stuffing box for the stem, but the stem only travels one-quarter turn - and the inlet and outlet teflon seals on the valve body keep pressure off the stem. No backseat required.

I'm trying to think of an advantage a gate valve might have for relatively small lines, say 2.5" and smaller, and I honestly can't come up with one.

There must be some advantage, since gate valves are sold down to 1/4" (FIPS). I see that bronze gate valves are cheaper than full-port ball valves, so maybe that is the explanation.
 

Last edited by Mike Speed 30; 04-26-10 at 03:26 PM.
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Old 04-26-10, 04:29 PM
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Funny that I've always been wondering that Mr. NJ-Trooper is a cop & how he gets involve in such as these heating technical business !! then in one post that he told some lady that he was running a clown school (wondering if Mr. Trooper is serious) !!
There's more than one kind of Trooper! and this one here is a joker... love to have fun... but when it comes to heating systems, I'm pretty serious!

Over the years, with multiple boiler changes, and system changes, heating systems can become all tangled up. Sometimes it's best to just rip it all out and start over. (The Mike Holmes approach)... sometimes with proper planning, relatively minor changes can be made that will correct problems with a system. There needs to be a balance between these two schools of thought. Unless something is REALLY messed up, I would take the minimalist approach... because I'm lazy... the least work to fix something is where I would go. This is what you need to think about.

Sure, it would be nice to have a valve here to do this, a gauge here to do that, etc, etc, but the bottom line is that all you really have to do is find a way to drain your tank... why make a bunch of extra work for yourself?

As Mike said, twisting and un-twisting those big pipes is SERIOUS work... for a person with SERIOUS muscles... and the tools needed to do this work are NOT cheap!
 
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Old 04-26-10, 04:55 PM
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Originally Posted by rbeck View Post
I like the old steel tanks. Zero maintenance.
A conventional steel tank is half or more filled with an air cushion that is in direct contact with water. So, I used to assume the water (that flows in and out of the tank as the system temperature changes) was saturated in dissolved air. And I wondered about the possible corrosion due to the disolved oxygen in the tank water.

I think that in rather short order, the oxygen disappears, leaving only inert nitrogen (which comprises about 80% of air). What happens to the oxygen? It combines with ferous alloys, forming maybe some rust but mainly that complex oxide of iron that makes the circulating water black very quickly after refilling the system. This is all my theory, and I stand ready for pie throwing.

This might also explain furd's poor industrial experience with steel expansion tanks. Were they totally closed systems, with no make up whatsoever? If not, the tank internals may have been exposed to oxygen-saturated water continuously? But, whatever, I do think the experience with properly installed conventional tanks in residential, hot-water systems is an indefinite lifetime.

A conventional tank should never lose it's cushion. If there is any makeup water supplied by the pressure reducing valve, any air dissolved in the makeup will eventually wind up in the tank (assuming it's properly installed) and then wind up being 100% nitrogen.

Now, a bladder-type tank will lose its air cushion, over time, due to diffusion of air through the rubber membrane - just like your car or bicycle tires that lose pressure over time. Periodically, the tank's water side has to be depressurized and the air side pumped up with a bicycle pump. Few of those systems are sufficiently valved to do this without drainng the whole darn system - and adding a bunch of additional air to the circulating water when the system is refilled.

I am a big fan of John Siegenthaler and I shelled out $bucks for his book, Modern Hydronic Heating, 2nd ed. But his book is mixed up, in my opinion, on p. 460. He asserts that conventional steel tanks eventually lose their air cushion because the air dissoloved in the tank water will eventually surge out and be expelled by automatic air vents. Of course, properly installed systems with a conventional expansion tank do not, and must not, have air vents. Any dissolved air in the water that surges out of the tank will wind back up in the tank.
 
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Old 04-26-10, 05:01 PM
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Originally Posted by NJ Trooper View Post
There's more than one kind of Trooper!
We knew you weren't a cop - your working hours are way too regular! Home at the same time every day and always home on weekends and holidays.

I've got you pegged as a bank teller.
 

Last edited by Mike Speed 30; 04-26-10 at 05:42 PM.
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Old 04-26-10, 05:52 PM
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Originally Posted by NJ Trooper View Post
twisting and un-twisting those big pipes is SERIOUS work... for a person with SERIOUS muscles... and the tools needed to do this work are NOT cheap!
Go to the beach and hire some stud, for $25, who looks like Charles Atlas, wearing a tight-fit Speedo.

Seriously, the arm-muscle issue is real. I don't have them (never had). I do have a couple of pieces of 2" pipe that I can use as cheaters with my 24" pipe wrenches. The problem is, if anything slips, you're a basket case!
 
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Old 04-27-10, 09:26 AM
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Mike speed you are totally correct in your thoughts on steel compression tanks.
Also to add a fact about the bladder type tanks. The bladder is oxygen permeable so the oxygen ends up in the system. That is why many tank manufacturers have gone to charging with nitrogen, plus nitrogen is way more stable with temperature changes.
 
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Old 04-27-10, 02:48 PM
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Thanks for all your inputs.
I learn so much from your responses, and thanks for info about gate valve vs ball valve, and the early warning about big wrenches & muscles requirement to tackle these big pipes that I did not consider.

Per Mike Speed quotes:

"are you intending to add an IN-LINE-AIR-SEPERATOR ?"

- Yes, I think I needed one, otherwise air keeps circulate thru syst. and req'd to bleed. As I may consider DIAPHRAM-EXPANSION TANK as recommended by Mr. Furd.

"there needs to be a PRESSURE REDUCING VALVE between the city water and the boiler. Are you sure you don't have one ?

- I am sure current syst. do not have any valves at all, except one globe valve for manually inlet water for the syst. and one PRESSURE RELIEF VALVE came with the boiler.
Can I not intall the PRESS-REDUCER-VALVE and BACKFLOW
because syst. can be manually add water when needed ?


Thanks
PAT
 
  #29  
Old 04-27-10, 03:06 PM
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If you go with a bladder-type tank, you don't want the B&G in-line air separator that I mentioned. Here is basic info on bladder tanks: http://www.amtrol.com/pdf/MC2680EXTROLBrochurelow.pdf

I guess you can get by without a pressure reducing valve and just rely on your manual fill valve. It will make filling the system less automated. You will need to keep adding a little bit of water from time to time for several days while trapped air works its way out of the system. The manual fill valve needs to be 100% leak-tight, or the pressure in the system will slowly rise, lifting the relief valve. I would install a new valve, either ball or globe.

Some people, maybe not most, rely on the PRV valve to automatically add water if there is a leak while you are not at home. But, perhaps your boiler system has a low-water cutoff - which would eliminate that concern.
 
 

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