3/4" steam valves; some frozen some open/close partially

HowieRavi

Newbie here, but with a brain(on a good day) and some experience.

I have a steam system in my new house (built in 1928.)

Some radiators work just fine, valves open and close all the way.

Others don't open at all. Some open and close partially.

The location of the valves prohibits replacement.

The box was made by McQuay. Can I conclude that  the valves are likely McQuay? Can I replace the guts or the packing on the valves? how can I get it apart without killing the brass?

I'll take some more photos and add them. 

nicholas bonham-carter

frozen valves

not sure about your system, but some valves were immobilized by setscrews after initial adjustment to let only a certain volume of steam into the rad, so have a look and see if this is the case.

this system may need very low pressure to function properly [see vacuum/vapor], so do a search here for the maker's name and see if anything comes up.--nbc

Steamhead

McQuay

probably just made those convectors, with the rest of the system's hardware coming from another source. Take some pics of the boiler and any strange-looking devices in the piping around it, and see if there are any names on them. 

HowieRavi

photos

Hi Folks, some photos. It seems like others in need post photos of their boilers as well, so here goes! We started to insulate the pipes but have not yet finished.



If I could screw out the valves that are not functioning properly I would. There just isn't enough room to do that. I suppose if repair is not an option I would have to remove the case? and open the walls and create more space and the replace the valves and do a whole lot of wall repair etc...

nicholas bonham-carter

frozen valves

the packing nut on those valves could be loosened, and then the stem may move once again. if not, then the bonnet may be removed with the stem, for rebuilding, or removal. often, the packing nut gets limed up and sticks to the stem.

i would use a good set of deep sockets to get a grip on these parts, and they will be less marked up than removal by wrench.--nbc

HowieRavi

bonnet and stem removal

any tricks in loosening them? and how / what would be rebuilt? 

nicholas bonham-carter

bonnet removal

get some deep 1/2 in. drive sockets with an extension, so you are clear of the recess the valve is in.

first loosen the packing nut, using steady force. it will help to balance the force you apply to the handle with an equivalent opposite push on the turning point. this will reduce the resultant force on the valve body, and pipe.

once the packing nut is very loose, i would think that the stem will move as it should, and you're done except to tighten the packing nut again.

if the stem is still frozen, then off with the bonnet [there may be a slim washer], and soak it in some penetrating oil for a while, and work it until it is free. wash the oil off before re-installation

if they are gate valves, then the gates may have dropped off the stem, and maybe could be repinned, or removed entirely [just the gates].

if that is not successful, then you can either put up with a non-functional valve, or find a new valve whose length exactly matches the old one. without the bonnet, it should be able to be spun off even in a tight space. i think i would put up with the non-functional valve, if it was open.--nbc

HowieRavi

more photos

Valve:

Got the first one off. Cleaned everything up. Just not sure whats going on...

The stem is a red rubber like material. As the stem turns, the end meets up with the valve opening and closes the opening. right? The distance the stem travels seems to be too little to create much of an opening. When the bonnet (hope I am using the correct terms) is not installed it turns free and clear all the way in and all the way out. When installed it turns about 1/4 of a full rotation.

Trap:

The trap cap has a copper accordian-like bellows. Its got virtually no movement in it.  I have no idea what to do with this...

THANKS SO MUCH FOR YOUR HELP!

crash2009

I don't know how to say this nicely

NBC gave you instructions on how to take apart the shutoff valve, You have now dis-assembled a steam trap. 



I sure hope the boiler is shut off.

nicholas bonham-carter

trap removal

maybe you can test those bellows, in a pot of boiling water. the bellows should expand when boiling water is poured over them. if there is no reaction, then it's new trap time, and replacement inserts are available, but i can't remember the source, as i have 1-pipe steam. most likely, you will need to replace all those which are on cold radiators, and better yet, all at the same time. if the bellows do expand, then is there any thing which could jam the bellows operation? the traps are pressure-sensitive, and therefore it would be best to monitor your pressure with a low-pressure gauge [0-3 psi-gaugestore.com].

the valve disk looks good, and if the stem will rotate properly, then it seems capable of doing its job. what happens if you reinstall the bonnet in the open position? to avoid cross-threading, turn the bonnet counterclockwise, until you feel the threads "mate", and then tighten. i don't see any calcium in the valve chamber which would bind the disk

since this is obviously a vapor system, there may be some other device in the basement on the returns which lets the air out as steam rises, and if that isn't working, then the steam will not enter the radiator. maybe the non-functioning radiators are on the same return, now air-bound. dan's books, from the shop here, give a good explanation as to how these various devices work. --nbc

HowieRavi

thanks

Boiler was off, Weather was warm, no threat of the boiler running. The valve and trapwere reassembled after the pictures were taken. Everything went back together easy and tight. Not sure what concern you are trying to point out..

HowieRavi

Thank you NBC

I will definitely test the bellows of the trap in a pot of boiling water.

Rod

Radiator Traps

Hi- Fixing intake valves is one thing and fixing traps is another. I would fix the intake valves first as this will then allow you to determine if it was a bad intake valve or a bad trap that made the radiator non operational. It will also allow you to shut off the radiators where the traps are bad and isolate a bad trap from the system.

 I would be inclined to leave the traps alone at this point as cold weather is nearly upon us. The traps need to be fixed  all at the same time which  usually makes this task is a warm weather one which you do in the spring. If not fixed at the same time, the non operational traps, by letting steam into the returns, can destroy the new/good traps.

 

Parts are available for traps, even the very old ones. Here are some sources for trap parts.

Source for complete traps & parts:

State Supply

http://www.statesupply.com/steamTraps.jsp



Rebuild parts for Steam Traps (Thermostatic,  F&T)

Barnes & Jones

http://www.barnesandjones.com/



Tunstall

http://www.tunstall-inc.com/tunstallsteam.html



The best way I‘ve found to test traps is with an IR Thermometer.  I use a Ryobi  Tek4 Infrared Thermometer Model RP4030 which are available from Home Depot. With the system operating, you measure the temperature on radiator side of the trap and then temperature on the  return side of the trap and then compare the two measurements. If the temperature is close  to the same, you have a bad trap. If they are 10 to 15 degrees apart, your trap is good. You have to practice a bit to get good readings. Use the red lazer dot and take the measurements up close to the trap as taking the measurement farther away scans a wider area and therefore may be more inaccurate.



I’ve also attached a couple of drawings that may be of help to you.

- Rod

nicholas bonham-carter

trap testing

rod is right, but since you have let the trap out of its cage, it wouldn't do any harm to see if the bellows respond to boiling water.--nbc