Fitting for stovetop steam trap testing?

ariccio

I'm continuing in my saga trying to explain the basic fact that "thermostatic steam traps can actually fail open" to some of the relevant people in my building.

Yes, I'm probably going to have to put together a PowerPoint and use a whiteboard. But I'm sure that'll raise some disbelieving appeals to authority and credentials. So the final step I see is building one of Dan Holohan's stove top steam trap testers.

Really not too difficult of a proposal. It's a pot. The main risk is idiots turning the pot into a pressure vessel.

The question I have is the single fitting at the joint between the pot lid and the pipe fittings. What do you use for that?



I'm not a plumber. I see tank take-off fittings on McMaster-carr, but they mostly appear to be weld-in fittings, and I'm even more not a welder than I am not a plumber. 

Presumably there's a simple two sided threaded fitting out there that I can push through a hole in the lid?

I'm not too worried about how to get it perfectly leak tight. It's not gonna hold real pressure, and I figure I can use some high temperature epoxy to hold it for at least long enough to demonstrate.

If necessary, I guess I could use the high temp epoxy with a weld in fitting instead of welding and pray?


If I was flush with cash, I'd just buy one of these pressure cookers on Amazon that seem to have fittings already for the gauge:




That one is FOUR HUNDRED BUCKS though

KC_Jones

I'd be using a bulkhead fitting. For what you are doing it doesn't need to be fancy or "high end"

https://www.amazon.com/RAINPAL-SSBF020-Stainless-Bulkhead-Threaded/dp/B08QC4SLCS/ref=asc_df_B08QC4SLCS/?tag=hyprod-20&linkCode=df0&hvadid=508033712127&hvpos=&hvnetw=g&hvrand=5617146485884297711&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9008063&hvtargid=pla-1319298635034&mcid=141c4683dae13374960f363cec55f549&gclid=CjwKCAiAivGuBhBEEiwAWiFmYYp6YPIbVduQPyqt96yysR5-U4iZNNraFxVJb2dX3byW5vJUHCpgdhoCiHcQAvD_BwE&th=1

dko

I see plenty of pressure cookers with threaded pressure gauges under $100 on amazon

you can also consider those electric portable steamers like this one
$60 and make whatever you need after a barb adapter.
this way you also dont need a stove and flame. many different ones to choose from, some with more safeties.

Sylvain

One doesn't need something perfectly tight as long as one can show that steam passing on a functioning trap will cause it to shut. (and the contrary for a failed one).

Looking at the first picture, one will notice that the lid will slightly rise up if the pressure rises enough letting some steam to escape.
This will automatically limit the pressure ( wheight of [ lid + fitting + steam trap]/ lid area).
One can see on that picture steam escaping at the rim of the lid. No explosion risk.

Don't use a pressure cook pot.
Find a large cook pot (to have a large lid area ) in a second hand store and use something as proposed by KC-Jones.

Could you use the building boiler itself for a demo? It would show the real thing and it would not explode.
(a valve, some length of tube (with a wet cloth on it ?) to have condensation and the trap fitting at the end)

Sylvain

example of trap testing station in the last picture of this thread:
https://forum.heatinghelp.com/discussion/171067/a-false-water-line-is-a-true-solution-to-water-line-issues?utm_source=community-search&utm_medium=organic-search&utm_term=false+water+line

Of course the false water line is not needed for trap testing.

Gordo

@ariccio: You might try this over-built steam vent tester. You should be able to test traps with it.

https://youtu.be/53_wqEp9duU

ariccio

Heh, I already bought all the cheap parts for the stovetop tester, we'll see if it's any good when I find the time to drill the hole and connect it all up 🤞👍

ariccio

First test was successful!


https://youtu.be/i0ZI5b1DiLY

Looks like I'll need to change that rubber washer for something a bit better. Also disassemble and re-assemble with new thread tape. Now that I know it works, maybe I will indeed rig something up with a wye and a gauge. The gauge will at least make me a bit less terrified about working with a pressure vessel that can be anywhere from 0-15psi

EBEBRATT-Ed

A gauge would be nice. Is that not a safety valve on top?

ariccio

Yeah, it's a gravity kind of pressure regulator. When enough pressure builds, it floats a bit and lets out a puff. But there's no way to tell if I run it dry right now, and no way to know exactly what the pressure is.

109A_5

Hello @ariccio,

I probably would have just added a pipe and a valve or two to the actual building's boiler and make a test station (plenty of steam and built in safeties). However the stove top version may be useful for off season testing. Here is one example video, there are others from this YouTube channel.

https://youtu.be/_PMOxiseh0g

redxiii5665

Better to tap into a steam pressure gauge drip leg

ariccio

Update:
An accessible steam trap in my apartment finally failed open, and I was able to get the super to come upstairs. He removed it from the radiator, we attached it to the trap tester, and turned the stove on.

Sure enough, it started blowing live steam right through in a few minutes. It really blew his mind! He was very impressed, and I could tell some new gears were turning in his head with the new knowledge. Now he realizes and admits for the first time that there for sure are traps in the building that have failed open, and that might have a role in heat distribution problems in the building. Success.

109A_5

Sadly, if he realizes how many traps he now needs to repair, he may swing back to being the old Super.

Why not just replace the cage unit instead of the whole trap ?

mattmia2

you can get a wafco/all american pressure canner like that when it is not canning season this time of year for like $20. I would use a nipple, 2 electrical locknuts, and some o-rings or washers.

you can also just put the cage in hot water and see if it expands. I wouldn't leave it there more than briefly unrestrained in the housing, some bellows can be overextended and damaged without a housing to restrain them.