illinois 6G F&T trap assessment

archibald tuttle

have two of these 3/4" illinois traps on twin 50' 2" feed mains vented into returns on a two pipe steam systems with an old snowman putting out about 225,000 btu with propane conversion burner.

i'm having slow heating of the radiators that take off immediately upstream of these traps and i'm guessing that the traps may not be closing although the distance back to the condensate tank appears to be enough for condensing any this is leaking through so i'm not seeing steam at the vent in the tank. eventually, long steaming, these rads do heat. i pulled the elements in the steam traps at the radiators and only saw mild change. the piping immediately downstream of the F&T traps is pretty close to identical temp. with the upstream side making me think i might be passing some steam albeit not enough to heat the return piping to steam temps even 10 feet away.

I haven't flirred this yet to see if i can really trace how close the temps are across the trap, those are finger estimates. and i'm going to bring a type K pipe clamp temp indicator home from the job (this is my place). Ironically if the thermostatic trap were stuck shut that would slow steam to those ends and then maybe the float is passing really hot condensate fooling me into thinking it is stuck open, so i could have a bad trap stuck in either mode. So I'm not giving complete diagnostics yet. But the traps haven't been serviced in decades and the full kits cost as much as a new trap can be got for (tunstall has thermostatic capsule and cover pretty reasonable assuming I could get the old cover and element off - did just fill my acetylene tank. i'm speculating if it might be physically easier to just prophylactically replace the traps. Again Tunstall fair on new although I never mind those dusty ebay units for major discount.

Since I'm not passing steam by the end of the return wouldn't be losing sleep over this at all except i'm trying to get those last two radiators to heat more quickly (Actually convectors, the folks who put this system in in the 50s were trying to be space age, didn't realize that cast iron probably would have been a better choice, but i digress). And I suppose i could try throttling valves on other radiators since i don't know of any adjustable replacement elements for the trap side of radiators (1/2" dunham 1Es).

One other possibilty that occurred to me since i'm considering replacing the traps anyway is to enlarge my search to include other manufactuers units that have similar capacity (About 100 MBH) and piping geometry (straight through with about a half inch drop although I could get a straight through pattern with no drop which i see on a lot of bucket traps to work):

https://media.statesupply.com/filemanager/1/5/15012015-illinois_ft-trap_specifications.pdf

If I increase the acceptable range of manufacturers products i could use, I've got a lot better chance of finding some decent dusty stock on ebay for christmas present price.

My problem is it is difficult to sort when searching to restrict to F&T traps. Most of what is coming up are bucket traps intended for high pressure steam. I'm not sure if I could use one of these to replace the "F" function and then tee up for a separate thermostatic trap above (have room and could pipe). But I'm wondering when I have such a small pressure differential whether these traps designed for 150 and 250 psi even have a rating of openings sufficeint for operating at a half pound. Or maybe there are some F&T options that are know the cognoscenti here and if I had manufacturer and model or series designation I could use for search restrictions.

Thanks to said cognoscenti for any thoughts,

Brian

Sailah

Brian,

Yes you can repair air vents in these but if the float seat is bad then you are stuck. I don't think repairs on these are economical.

Inverted bucket traps can be bought in 15PSI ratings but these are not good options for you since their venting capacity is extremely limited to the tiny hole on the bucket. IB traps are designed for, and work best, when operating continuously. For a heating application they are not a good option.

For an inline option to reduce repiping, you could opt for an inline Float and Thermostatic that uses a modern faceplate type repair. Example would be a Spirax Sarco FTI-15, Barnes & Jones FTI2015-3 (3/4"). These were designed to replace inverted buckets misapplied in heating applications because they vent much faster and that's what you want in a heating application.

https://www.ebay.com/itm/Barnes-Jones-FTI2015-3-F-T-Steam-Trap-15-PSI-Free-Ground-Shipping-USA/193060153682?hash=item2cf3482952:g:-WAAAOSwm5ZdXXV6

Do some searches for inline float and thermostatic using part numbers you find on State Supply if you want to look eBay etc.

You'll have to move the pipe 1/2" but this will ensure the F&T traps are new and working and future repairs will be available as all manufacturers have standardized on this "faceplate" type repair. In fact most of these faceplates are all interchangeable since they were copied from Spirax Sarco long ago.

archibald tuttle

@Sailah thanks for those model numbers for inline style. gotta see if armstrong has an equivalent just to broaden search for even more options but found a few including the one you linked which would get me into the modern era . . .

Sailah

Just an FYI, Armstrong will be significantly more expensive when it comes to actual traps and esp repair parts. And they can't use any of the secret interchange Sarco pattern either.

As far as I can recall, the following faceplates are essentially interchangeable from:

Watts FT15, Hoffman (FT015H not FT43), Barnes & Jones FT2015, Sarco FT15, Erwel, Tunstall

That said, the inline faceplates are NOT interchangeable with the regular 4 port "H" pattern.

archibald tuttle

@Sailah thanks again. so this hoffman FT015H has 4 tappings and doesn't look like an inline but maybe they actually have a layout that goes both ways rather than the two top tappings representing alternatives for entry?

https://www.ebay.com/itm/ITT-Hoffman-FT015H-3-F-T-Float-and-Thermostatic-Steam-Trap-3-4-Bear-Trap-New/293170264126?hash=item44424f383e:g:9zkAAOSwIVxdP3p6:sc:FedExHomeDelivery!02822!US!-1

Sailah

No all H type traps will have 2 ports at the top, these are the inlets. The 2 ports at the bottom are the outlets. You can use either inlet and either outlet but you cannot use in "inline" mode. You block off the unused ports with pipe plugs.

If your piping will permit that vertical offset, you will find a lot more options since that H pattern is more common than inline. But if it's going to require a lot of repiping or you can't tolerate the offset, you are better off buying an inline F&T.

archibald tuttle

@Sailah that's what I thought, so maybe they are designating that hoffman incorrertly that i linked? i find a fair number of those FTO15H which i thought was the number you said was good for a match but they are the H pattern. should it be FTI015H or . . . ? obviously only if it jumps to mind. i can go plumb their web site and try to see how to delineate. thanks, brian

Sailah

Sorry, FT015H dechiphered is Float and Thermostatic, 15 PSIG, H pattern. Thats not the inline. I think they call it FT015I for the inline but not 100% from memory.

That Hoffman is a regular F&T and you could use it if you repiped to deal with vertical difference. That specific trap is the generic model i was referring to that can accept faceplates from Barnes & Jones, Sarco, Watts etc.

The inlines look the same but they work differently so you need to buy an actual inline or inline repair kit even though the bolts line up.