Best Of
Re: Now ya see why PVC on mod con flue is not a good idea
This was 3"pvc... .I agree with Bob Harper...we're all just taking a stab at why...only a lab analysis can possibly determine why it pulled apart. Let's just keep an open mind....could the manufacturers have very sound reasons for disallowing pvc in flue exhausts?
Could acidic flue gases cause this is as well? Mad Dog
Re: J.P. Ward
trade jobs and manufacturing have gotten such a bad rap the last 30 years or more, not because they were ever bad jobs but people with degrees had much better communication skills and wooed the kids away from the trades/manufacturing by telling them the degree was their golden ticket to the mountain top and of course we wanted all of our kids to do well, so many of us allowed them to pursue the degree.
Now we are upside down in degrees vs good hand skills. It will take some time but funding trade type schools and classes in regular schools as well as better advertising of the factory/trade work environment would help. The pay is good, the benefits are good, low/no debt upon graduation, typically a job lined up at graduation all good stuff.
Build the plant the hands will come.
Re: Single pipe steam system return pipe reroute
This is a cheap installation that can prevent problems though rare where some type of pressurization from the boiler may occur causing water from the boiler to back flow and cause a pressure lock at the trap causing a no flow condition.
This method typically is used where condensate goes below a beam, the jump over equalizes pressures that can occur down stream of the trap.
This is shown on page 50 of my book Steam the Perfect Fluid for Heating and Some of the Problems.
Jake
Re: Now ya see why PVC on mod con flue is not a good idea
high temperature systems with PP and long horizontal run can be a problem if not supported properly.
I have seen the piping sag and leak condensate at the joints.
HTTP failed , standard PVC and CPVC isn’t the best solution, some stainless suffered gaskets or silicone adhesive failures,
Hopefully PP holds up better. It is a harsh environment for the tube and seals
Dirty or plugged HXers can run the flue temperatures up pretty hot. Hot enough to trip temperature safeties.
Mod cons in DHW mode are generally exceeding the PVC, maybe even CPVC temperature limits
Not to mention the lack of listing for flue gas conveyance on typical PVC pipe
Yet manufactures are still sending equipment out with PVC or CPVC “starter pieces” PVC fittings and rubber sewer pipe connectors😲 Some brands sent ABS start pieces, which would often get connected to PVC. Crazy!
hot_rod
Re: Now ya see why PVC on mod con flue is not a good idea
You can armchair quarterback your opinions and guesses as to the failure but without lab analysis you are still just grasping at straws. Was it installed per the mfrs. listed instructions as well as those of the PVC pipe mfr, the primer and the solvent cement? Was the pipe used within the approved applications by the pipe mfr? Was the pipe properly supported? Was it leak tested prior to use? Was the appliance inspected and tested including gas pressures, orifices, firing rate, MUA, intake air obstructions/ sizing/ pressures? Flue gas outlet temperatures? Any signs of overfiring in the unit or historical evidence such as tripped safeties? Was the heat exchanger ever replaced? Lot's of questions in a forensic investigation.
I don't like PVC for a number of reasons: The pipes out there were never listed for this use but specifically forbidden per most pipe mfrs. While the pipe itself might withstand short term temps upwards 170F, the solvent cement routinely fails at 140F or lower. I've never seen an HVAC tech properly cut, chamfer, deburr or join PVC for venting. Never. I see pipe cut with a Sawzall held with one hand and the pipe with the other. The end of the pipe resembles a hole saw with all its jagged edges. The end is never chamfered nor deburred and there is no way to tell externally once the joint is made. Meanwhile, inside, the rough joint plows the cement pushing a dam of it ahead while scraping cement from the outer walls. The result is a very weak, often leaky joint.
The pipe mfrs. expressly FORBID pressure testing with gas, such as done with gas piping. You can do a low pressure water test but how are you going to test the seal on a flush wall termination like a Bayvent? You would have to test with the pipe extended, tested, cut to length and attach AFTER the test. You might be able to rig a test ball in some cases. Also, on long runs through crawlspaces, you may get a few drips that harbinger a future failure yet not manifest during the test duration. You have to rely on one end of the pipe or another just as with gas pipe testing. That brings in the gauge resolution, test duration and allowable leakage. It has to be reasonable yet reflective of the conditions.
The UL 1738 test seems fairly reasonable and reliable. It is also repeatable.
Everything made by man can and will eventually fail. It's just a matter of when and at what cost.
Re: Now ya see why PVC on mod con flue is not a good idea
I am a bit curious on how you came to that conclusion. How can you know if it bottomed out or not by looking at the two photos? You certainly cannot judge this by the length of the primer.
Re: Torque Wrench
We had a rash of electric unit heaters burn up the terminals on the disconnects and/or contactors. I ended up getting a torque screwdriver for the replacements, no issues since then.
I wouldn't say I'm a true believer just yet, but the evidence is mounting so I use it when I can.
Re: Need help choosing between Comforto (Granby) and ThermoPride oil furnace
I don't know about Conforto. Thermopride is generally considered to be the best and most expensive oil furnace.
Your old one lasted 36 years that is a good run for an oil furnace. General rule of thumb is 20 years. You generally want as much return air as you can get it should not be restricted.
Re: J.P. Ward
The numbers just don't work to build factories in the US. Currently the labor department estimates 400,000 unfilled factory jobs in the US. They are looking for the same people as all the trades. Looks like we may be going in the wrong direction with entry level job workers these days. Farm workers, factory workers, construction labor, hospitality and food processors are leaving by the bus loads. A shiney new factory with no workers doesn't help much.
Modern factories to be accurate, fast and competitive will be automated. 65% of those jobs will require a degree. These are not low pay entry level jobs and wages. As such the cost of the product needs to cover those wages.
With a new pickup built in Mexico costing upwards 100 grand what would a truck 100% sourced and built in America cost?
Factory jobs, just like trade jobs, and farm jobs have a stigma of low wages, long hours, dirty, possibly unsafe conditions, etc. A major PR issue like our trade. How many people do you know applying for a factory job? Money motivates American workers these days, for the most part.
Farm land and factories are still being gobbled up by foreign investor group.
Uncertainty around tariffs, their %.
Raw material, partial assemblies will still come from across the globe, as the average US built car is 45% imported components.
Not a lot of discussion on how to over-come these obstacles?
There will be a lot of lip service and promises by manufacturers to build US factories, once they run the numbers on the costs involved to build a widget, even if the tax payers cover the cost of the factory build, in the US, not enough consumers are buyers. The stall is on.
China with its 1.4 billion people, a huge, low cost labor pool, started planing in the 1970s to become the worlds tool box and manufacturing powerhouse. They started with massive infrastructure investments.
Around here we barely have enough power to keep residential AC running on a hot day. Interstate grid lock every day. What happened to the 2018 focus on infrastructure improvements?
It starts with a realistic vision, then a pathway to get there. Our leaders, whichever party, just pinball from one problem to the next on a daily basis. Flavor of the day, what makes the headlines.
It would be nice to think someone, enough of us, are working in the background to get er done??
hot_rod
Re: Oil to propane, Kingston NY area - EDITED.
But, how many people actually get proper maintenance done?
It's the same basic principle that makes me favor probe-type low-water cutoffs on steam boilers as opposed to float-type. Folks tend to forget to blow the float-type ones down. Yes, probe units do need to be checked annually, but annually is not weekly.
ISTR @Mark Eatherton once ran a mod-con without maintaining it, just to see what would happen. Its efficiency dropped noticeably. I've forgotten how much, it's been quite a while.

