omg now what am i going to do?

Re: omg now what am i going to do?

PostBy: CoalisCoolxWarm On: Fri Jan 31, 2014 3:27 pm

What kind of fittings are you using, and how much pipe do you have between the boiler and where the pex starts? I hope you didn't plumb pex directly to the boiler.

Bad luck for you, we're looking for answers for you, so please don't be offended about the number of Q's. It's always better to identify the problems if you want to avoid them again.
CoalisCoolxWarm
 
Stoker Coal Boiler: Keystoker KA6
Hand Fed Coal Furnace: old Sears rebuilt, bituminous
Coal Size/Type: Kittanning Seam, Stove size
Stove/Furnace Make: old handfired bituminous

Re: omg now what am i going to do?

PostBy: coaledsweat On: Fri Jan 31, 2014 4:41 pm

GaryFerg wrote:Today when I got home I walked into my shed to check my boiler to find a steam filled room.

Just so you know, it was water vapour, not steam. Steam is an invisible gas. If you see it, it has reverted to water vapour.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: omg now what am i going to do?

PostBy: Freddy On: Fri Jan 31, 2014 5:05 pm

kstills wrote:PEX softens at 264F, melts around 330f.


Kstills, the web link you posted doesn't seem to work.

Can you show where that info comes from? I've never heard of it rated that high. Maybe from a scientific standpoint in a petri dish, but we need to take into account that it is moving a liquid under pressure. On the manufacturer's website, GT Globe, they write that Pex is rated at 180 degrees F at 100 PSI. They go on to write that in heating systems it will tolerate 203 degrees ( heating would be 30 PSI or less?) and "surges" of 230 degrees. That is what I referred to when I was told a surge is rated in brief minutes, no longer.
Freddy
 
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined

Visit Lehigh Anthracite

Re: omg now what am i going to do?

PostBy: kstills On: Fri Jan 31, 2014 5:17 pm

Freddy wrote:
kstills wrote:PEX softens at 264F, melts around 330f.


Kstills, the web link you posted doesn't seem to work.

Can you show where that info comes from? I've never heard of it rated that high. Maybe from a scientific standpoint in a petri dish, but we need to take into account that it is moving a liquid under pressure. On the manufacturer's website, GT Globe, they write that Pex is rated at 180 degrees F at 100 PSI. They go on to write that in heating systems it will tolerate 203 degrees ( heating would be 30 PSI or less?) and "surges" of 230 degrees. That is what I referred to when I was told a surge is rated in brief minutes, no longer.


Crud, that was the downloaded information, I'll have to dig back to see if I can find it.
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: omg now what am i going to do?

PostBy: GaryFerg On: Fri Jan 31, 2014 5:27 pm

this is a hand feed boiler. there is a blower which has a cover over it limiting the amount of air flow that cover had loosened and opened. Other than that I don't know much. I don't believe the relief valve blew off. Maybe the circulator failed I will not know until I get it hooked back up. I used no o2 barrier pex so switching to iron might be a good idea I can eliminate the heat exchanger I have going. I dont see how it could have frozen it has been working it was working when I left the house and I was only gone for about 4 hours. What I want to know if i use black pipe how do I direct bury it? insulate it?Maybe I can pull out the pex and replace it with iron pipe.
GaryFerg
 
Hand Fed Coal Boiler: Energy King boiler
Hand Fed Coal Stove: Harmon TLC 2000
Coal Size/Type: Nut
Other Heating: oil

Re: omg now what am i going to do?

PostBy: kstills On: Fri Jan 31, 2014 5:28 pm

In the event of a water heating system malfunction, PEX piping is designed to accommodate
short-term conditions of 48 hours at 210ºF (99ºC) and 150 psi (1034 kPa) until repairs can
be made. The most commonly used safety relief valve (T&P) activates (opens) at either of
these temperature or pressure conditions. All PEX piping has been tested to withstand T&P
activation for 30 days to ensure that safety requirements are met. As such, PEX systems DO
NOT require the use of a special T&P valve.
ASTM F 876: Standard Specification for Cross-Linked Polyethylene (PEX) Tubing covers
PEX piping that is outside diameter controlled, and pressure rated for water at three
temperatures—160 psi @ 73.4ºF, 100 psi @ 180ºF, and 80 psi @ 200ºF. Included are
requirements and test methods for material, workmanship, dimensions, hydrostatic sustained
pressure strength,


http://passthrough.fw-notify.net/static ... nloader.js
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: omg now what am i going to do?

PostBy: GaryFerg On: Fri Jan 31, 2014 5:34 pm

McGiever wrote:Understand you wanting to get heating restored ASAP...but how did the system allow this extreme temp on pex to happen in the first place?
Sure adding black steel pipe allows one to ignore the root cause of the pex failure, but shouldn't the pex failure cause be understood?
For pex to rupture @ 12 psi there had to be some grossly high water temps. and that needs a remedy. And I doubt a thermostatic mixing valve can do it...mix valve needs to have cool enough water from return to dampen the supply. This water temp that ruptured the pex needed "Dumped" to a zone way before it got hot enough to rupture pex.

Did you have an ice in pipe blockage that might of caused this?
Blockage in pipe raises pressure up to match the pressure pop-off valve...30 psi.
We need to find out the cause...pex is a good product when properly installed.
Steel pipe doesn't like ice blockage either. ;)

I used to have a dump zone, my upstairs of the house that I didn't use nice cold water. But now I rent it out so guess I better figure something else out. Maybe I can find an old cast iron radiator that I can hook up as a dump zone.This used to happen all the time when I lost electric but now I put in a auto genset. I have heat just burning up the oil and now I am trying to keep the shed where the boiler is warm so the plants don't die not to mention nothing freezes.
GaryFerg
 
Hand Fed Coal Boiler: Energy King boiler
Hand Fed Coal Stove: Harmon TLC 2000
Coal Size/Type: Nut
Other Heating: oil

Re: omg now what am i going to do?

PostBy: GaryFerg On: Fri Jan 31, 2014 6:35 pm

Its about 30 feet from the shed to my basement. I have it hooked into a heat exchanger 80 plate I think. So I have heat via oil. That part was unaffected. I am sure that it just got too hot. I am hoping my circulator is still ok they are expensive. I am digging up the pex enough to grab a good end so I can tie it back in. I have the black sewer pipe exposed so I am going to try to pull it out to see the ends. tp bad I didn't put it all in a conduit.
GaryFerg
 
Hand Fed Coal Boiler: Energy King boiler
Hand Fed Coal Stove: Harmon TLC 2000
Coal Size/Type: Nut
Other Heating: oil

Re: omg now what am i going to do?

PostBy: GaryFerg On: Fri Jan 31, 2014 7:04 pm

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GaryFerg
 
Hand Fed Coal Boiler: Energy King boiler
Hand Fed Coal Stove: Harmon TLC 2000
Coal Size/Type: Nut
Other Heating: oil

Re: omg now what am i going to do?

PostBy: kstills On: Fri Jan 31, 2014 7:36 pm

Holy dog balls.

What pressure was your pump putting out?
kstills
 
Stoker Coal Boiler: WL 110
Stove/Furnace Make: Leisure Line

Re: omg now what am i going to do?

PostBy: CoalisCoolxWarm On: Fri Jan 31, 2014 9:24 pm

That doesn't look like oxygen barrier pex to me. The stuff I've seen and used always had a white coating inside.

Another thing, what diameter is the pex? If too small, you could have exceeded the btu carrying capacity of the pex.

Black iron or copper for the first few feet from the boiler reduced the hazard of having too much conductive heat from the boiler body (often cast iron ) from softening pex

Another thing you mention is not having the pex in an insulated conduit? Pex softens as it gets warm and is quite easily deformed or damaged when heated.

I have installed pex for gas boilers, but not sure about using on coal because of the same thing you had happen. After researching the drastic weakening above 195F, I am concerned enough to possibly use it for only difficult zones away from the boiler.

30ft underground run, right? You can use black iron, but you may want to use 1.25" diameter pipe, dig a ditch large enough to fill with insulating materials at least 6" around the pipes and water/debris resistant covering.

There are some here who have buried lines and can share their experiences.
CoalisCoolxWarm
 
Stoker Coal Boiler: Keystoker KA6
Hand Fed Coal Furnace: old Sears rebuilt, bituminous
Coal Size/Type: Kittanning Seam, Stove size
Stove/Furnace Make: old handfired bituminous

Re: omg now what am i going to do?

PostBy: waldo lemieux On: Fri Jan 31, 2014 9:46 pm

Are you sure the thing didnt freeze and then release hot water into the boiler area causing all the steam? That looks for all the world like a freeze break which would also eliminate the blow off question. It seems to me that if it had failed under high temp , it would have softened at the first fitting on the supply side.... :gee:
waldo lemieux
 
Stove/Furnace Make: efm
Stove/Furnace Model: s-20

Re: omg now what am i going to do?

PostBy: windyhill4.2 On: Fri Jan 31, 2014 9:51 pm

chinese pex ?? We have 1000' +/- of pex in use here,mostly under ground,none that color,we have had no problems in 7+ yrs.of use .Our OWB is not a "boiler", its an open system,is set up to shut off at 180*,but we have seen 200* a few times. CCW,did you not read the earlier post with pex info ?? DRASTIC weakening above 195* ?? where did you read that ?? 160psi@ 73.4*,100psi@ 180*,80psi@ 200*, boilers generally run 80# + ?????? I never heard so much negativity about pex as i do on this forum,& its biased & uninformed info about how poorly pex performs or holds up.Just read the posted report & become informed .No i'm not mad at you,just totally blown away with your post following the very informative pex info posted by kstills. :? Maybe i misread the info ?? waldo, sounds like you hit the nail on the head !!
windyhill4.2
 
Hand Fed Coal Stove: Crane 404 with variable blower
Other Heating: Oaktree OWB 600K

Re: omg now what am i going to do?

PostBy: CoalisCoolxWarm On: Fri Jan 31, 2014 11:10 pm

windyhill4.2 wrote:chinese pex ?? We have 1000' +/- of pex in use here,mostly under ground,none that color,we have had no problems in 7+ yrs.of use .Our OWB is not a "boiler", its an open system,is set up to shut off at 180*,but we have seen 200* a few times. CCW,did you not read the earlier post with pex info ?? DRASTIC weakening above 195* ?? where did you read that ?? 160psi@ 73.4*,100psi@ 180*,80psi@ 200*, boilers generally run 80# + ?????? I never heard so much negativity about pex as i do on this forum,& its biased & uninformed info about how poorly pex performs or holds up.Just read the posted report & become informed .No i'm not mad at you,just totally blown away with your post following the very informative pex info posted by kstills. :? Maybe i misread the info ?? waldo, sounds like you hit the nail on the head !!


Fair questions. I'll take you at your word that you are simply trying to understand the different information being posted and not take offense. None is intended in return, either.

I'll explain it like this.

Those who read about PEX get one impression about its capabilities. Those who use it understand the realities of PEX use are a bit more complicated than simply "This pressure at This temperature"

Have you ever seen a boiler plumbed with CPVC water pipe? Why not? It is actually rated HIGHER than PEX (100psi @ 180F)- according to the stamping. But anyone familiar with it knows how easy it is to bend and deform at those temps. (FYI, I am intentionally ignoring the 'glued fittings' discussion as it isn't pertinent to the temp/pressure comparison ;) )

Even PEX's stamped rating drops 20% (!) from 180F to 200F and that is the burst/failure rating.

Take a look at a PEX hydronic installation that has the supports too far apart on a horizontal run and you'll see sagging between just about every support. It was surely fine when installed and even once filled with water. Why then? Heat and softening.

Then you have the issues concerning the fittings. PEX softens easily on the ends. *Many* fittings depend upon a tight fit or even the elasticity of the PEX to maintain a connection (BTW, I do NOT trust the latter, I use copper crimp rings on water and prefer something like ProPex fitting for HVAC). As the pipe softens the connection can weaken and even fail. A brass fitting in contact with a major heat source (think boiler) can work like a heat gun or a soldering iron against the PEX tubing.

Standard, non-oxygen barrier tubing (think drinking water) PEX is often much thinner/weaker than PEX designed for hydronic heating.

Ever need to bend or straighten PEX? Heat it. When it cools, it keeps the shape. That's a good example of how the softening and deformation works.

Now don't get me wrong. I really like PEX and would prefer to use it any time it is appropriate. I like the way it cuts and installs. I do not like the way it deforms due to weight or heat, and I do not like how it tends to kink when cold. It is easily damaged from UV exposure, too. Most of these are easily overcome by following proper installation guidelines and selecting alternative materials in combination or when necessary as appropriate.

Back to the OP's situation....

While we are all still collecting info before making a rush diagnosis, I'll throw out my speculation from the pics and info so far.

I think that

1. Hydronic (O2 barrier) PEX tubing was not used, rather the tubing looks like standard water tubing and would weaken quite quickly.

2. Although no measurements are shown, the tubing looks like maybe 1/2"? Even at 3/4", it is very possible the system couldn't carry enough BTUs from the boiler into the building, resulting in an overheating boiler.

3. Why didn't the boiler overheat/overpressure halt the failure? As others mentioned, the lack of a heat dump- combined with the inability to carry away enough BTUs- and (speculation) the transition to PEX being too close to boiler (hot fittings) led to failure.

4. To speculate even more, it is possible the PEX wasn't properly supported and when it softened it deformed, possibly even kinked, leading to flow and pressure problems, making the situation even worse.

5. I am guessing the OP does not have an auto-fill valve attached to the boiler from the fresh water supply. If not, in addition to the inability to cool the boiler properly, the sudden outrush of water could lead to a sudden drop in system pressure, allowing the water to flash to steam (literally boiling within the system). Lots of bad things can happen in those situations, probably good the pipe actually failed, boilers are pretty tough.

Hope this answers some questions about PEX, my comments, and possibly even the OP's situation ;)
CoalisCoolxWarm
 
Stoker Coal Boiler: Keystoker KA6
Hand Fed Coal Furnace: old Sears rebuilt, bituminous
Coal Size/Type: Kittanning Seam, Stove size
Stove/Furnace Make: old handfired bituminous

Re: omg now what am i going to do?

PostBy: windyhill4.2 On: Fri Jan 31, 2014 11:40 pm

You see - I see +,you claim the rating drops,i see a rise in temp allowed when psi drops,a boiler is not going to have more than 30 psi ,the report i read had 268* @ 30psi,i have not advanced yet to posting links nor do i remember the link right now. Boilers don't generally go much over 200* & 30 psi ,do they ?? Have to plan our situation when we do switch to coal.
windyhill4.2
 
Hand Fed Coal Stove: Crane 404 with variable blower
Other Heating: Oaktree OWB 600K

Visit Lehigh Anthracite