Steam traps

nick31

I had a few questions about steam traps. 

What’s the best way to test to see if a trap is bad is there a certain tool to buy to make your life easier. In watching some of the heating help videos I’ve learned if a radiator isn’t working it’s most likely a radiator before it that has a bad trap not the one that has no heat. But if the basement is finished and the piping isn’t accessible I was wondering if there was a tool to help test steam traps to quickly diagnose a bad trap. 

I was also wondering if there was a chart or a table that told you what steam trap rebuild can go into what steam trap. For instance if there was an old Trane steam trap I needed to rebuild what Barnes and jones rebuild will work inside of it. 

KarlW

As a homeowner, who just went through this with a mostly finished basement myself, I ended up just replacing them all. I’m interested in the answer myself.

Needless to say, it was not as cost-effective as other solutions.

I had an old steam trap that isn’t made anymore from Illinois engineering company that doesn’t fit well with new valves (I need a short extension of the pipe to fit in a new steam trap). So I bought a bunch of new capsules and covers from Tunstall.

Jamie Hall

It's called the yeouch test. Get the radiator so it is hot all the way across. Really going. Then... the outlet from the radiator to the trap should be steam hot. You can't hold your hand on it. The outlet from the trap, however, should be noticeably cooler. You still can't hold your hand on it for any length of time...

Or you can use an IR thermometer on it. Inlet to trap should be at least 4 degrees hotter than the outlet, and more is better assuming the radiator heats...

nick31

I appreciate it. Lol while the first one is tempting I think I’ll invest in a thermal camera. 

Do you know of any sort of cross reference sheet or table that tells you what rebuilds work in different traps? 

EBEBRATT-Ed

When you have traps the best, simplest thing is to just buy new guts and rebuild them all at the same time and start fresh. Then save the old traps.

Or take and unused tapping off your boiler or steam main and install a trap station to hoo up a trap for testing.

But if you don't have that many traps that isn't usually worth doing. On commercial jobs with a lot of traps some companies just replace the traps every 5 years or so. It's cheaper than the time wasted fiddling around and troubleshooting.

@KarlW

If you have a bad trap that is blowing steam it can pressurize the return lines and cause back pressure on the rads with good traps causing them to not work well.

KarlW

@EBEBRATT-Ed That was my problem, and as I couldn’t find the source, I systemically replaced traps and/or guts on all my traps and it solved the first water hammer problem I had.

A co-worker of mine did steam trap work at Kodak during its heyday as a young apprentice pipe fitter. He was telling me about the test setups they’d use.

CLamb

KarlW said:

A co-worker of mine did steam trap work at Kodak during its heyday as a young apprentice pipe fitter. He was telling me about the test setups they’d use.

Please post descriptions of those test setups on the wall. Perhaps under a new post.

RayWohlfarth

Testing steam traps is not an exact science. I remember they used to have crayons which would melt at a certain temperature. If the crayon melted, the steam trap was leaking through. Next we used infrared cameras like they used to test you temperature in buildings during covid. If you saw high temperature at the outlet, that meant the steam trap was defective. Next I used my Flir camera and diagnosed them that way. The only issue is the steam trap could be leaking in the the next room and look like the trap is leaking through. The most reliable solution is using an ultrasonic leak detector and you could hear the trap actually operating. What I used for years was a simple stethoscope to listen to the trap after I tested the outlet temp. Hope this helps

STONECREEKSERVICES

Steam traps. Worked in power plants and downtown steam heat systems for years. Temperature differentials across inlet and outlet of traps good test of leaking traps and a mechanics stethoscope critical as can hear internal workings. Todays digital temp tools see minor differentials Even minor leaking in float or thermodynamic traps can be diagnosed.  Check working traps and get use to sounds, knowing what is good helps when find one bad. 

Scott.Malo

Hi Folks! Scott here from Tunstall Corporation. All good questions and comments! Much like what has been said, Ultrasonic listening devices can reveal the condition of a trap by listening to the opening and closing of the bellows. However, in boiler rooms or other area where it is loud with other equipment making all kinds of noise, we will use an infrared camera gun to show us condensate temps prior to the trap opening and discharging into the return piping. These temperatures can tell us a lot about the condition of the bellows. Again, like it was mentioned above, unless you have see-through pipes, the only concrete way to test a bellows for functionality is to use a steam station. During the off-season, one could remove suspect bellows and test it while discharging to atmosphere. You could then see if the bellows was partially failed (leaking steam) or blowing wide open (completely failed in the open position which 99% of time is the case) and repair accordingly.

EBEBRATT-Ed

We found the ultrasonic was the best. But if your fooling with radiator traps you better off just rebuilding the traps. We used to do large university campuses and they would just rebuild the traps every few years. It was cheaper than going around testing them & then going back and rebuilding them. When you set up right with the right tools you can change them pretty quickly especially if they are all the same.

Residential is a little different the traps don't see the same abuse but no one working on his own house is going to fork over big money for trap testing equipment.

Steamfighter49

From an old fart. We used surface temp thermometers to check the upstream vs downstream ( a little space away from traps) temps . Should be noticeable difference  +/- 10 degrees. This will find traps blowing thru. 

 Then as per Dan, all traps must be changed at same time as any bad traps will destroy new cage units. 

 Barnes & Jones had catalog to match the right cage unit / repair kit to all existing ones. Hope it available somewhere. 
 That’s it. 

CarlM

there are relatively inexpensive thermal cameras available, I use it to diagnose all kind of thermal issues, Very sensitive to minor heat differences that you find on a working trap. I found my steam riser in my wall. This hooks up to my iPhone's lightning connector. Run a couple of hundred dollars but it is a valuable tool. Also sell models for Android and USB-C
https://www.amazon.com/Seek-Thermal-Compact-All-Purpose-Imaging/dp/B00NYWABAA/ref=sr_1_3_pp?crid=TT2XO251UKCR&dib=eyJ2IjoiMSJ9.8w2G5iJxefhJSpmCRWxoQruE5iUUNgw_GmT2qGO1YH18OxclNld6A6SNHxnsCbFj-U4lpvEWRErIUvl8P3H2j2YXCZAcDXUHgmNUBhKE971PPi4E-WtmSATS0PMa_NgItqSt9jpRjs5ZVoRMwtyKllkD2YggybwwVPQCYrkYh3PrfbMR6Y73a_8CliICE2Jvsh3nBvOPHhucIaKOKcYmjGMM7lUyg8hdDzej2-aPhbQ.7Z-O0gNJI5rHcFoGex4BprSwJ4cpa4I1X6dSnaB1PnE&dib_tag=se&keywords=seek+thermal&qid=1705633565&sprefix=Seek+,aps,142&sr=8-3&th=1

109A_5

Hello @nick31,

There is a whole list for replacement B&J Cage Units for Trane steam traps. Other resources there too.
https://barnesandjones.com/
https://barnesandjones.com/products/repair-guide/thermostatic-t/

jc2lite1

@Steamfighter49 On a 2 pipe system, is it necessary to replace all the cage traps at the same time? I have 9 rads., all different sizes. I have replaced a few of the traps on the rads. that weren't working well, but not all. Also what about the on/off valves? All but 2 have the old lever action style. The 2 I replaced is because 1 was leaking and the other never had 1. Any feedback is appreciated.

Jamie Hall

On the traps. Yes and no. There is something to be said for just replacing them all, particularly on larger systems -- get what you need and set up a campaign and just go around and do it. On smaller systems, I'd be very inclined to say not -- assuming you can verify that this trap or that one is bad. On the other hand, if the system has been abused -- particularly if it has been run at too high a pressure for any length of time, probably just as well to mutter dire threats and imprecations and just replace them all.

On the valves -- if they aren't leaking (or, if they are, they aren't repairable) you can replace them, but keep in mind that you may need to replace the radiator spud at the same time, and they may not be quite the same dimensions overall, so it can turn into quite a chore. Otherwise, leave them be.

jumper

How about record keeping for each location? If you don't know when you did what where then you're always starting from scratch.