Best insulation for steam pipes

Voyager

philsego said:

Fiberglass is carcinogenic - read this. Unfortunately, most heating professionals seem to be unaware of this.

There are some brands of high temperature pipe insulation that don't use fiberglass. I like K-Flex Titan. It's easy to work with, reasonably priced, and won't kill you.

Dihydrogen oxide can kill you also. Almost anything, improperly used, can injure or kill you. Fiberglass is quite safe used properly and will withstand very high temps and last virtually forever. Foam works well for a while, but degrades over time. It is easier to install without causing harm (less need for PPE), but in a fire it can be very hazardous to the occupants of the home or the firefighters putting off toxic gases and huge amounts of black smoke.

Everything has its hazards. The key is to understand them and take appropriate precautions.

mikespipe

I like 1 inch thick fiberglass. It lets you cut out a bit  and go over the fittings. It is much more effective than 1/2 inch. Touch 1/2 inch and it's warm to the touch. Use it on exposed pipes where some could get burned. . Ie. bathrooms with a pipe for heat cover the first 6 feet with 1/2 inch and leave the rest exposed. You will get a bit less heat but it is. Safer.

Thicker would be even better but 1 inch is easier to get, and costs less. And for residential low pressure steam is plenty good enough.  Wear a mask and gloves when cutting fiberglass.

Lance

I disagree with fiberglass causing cancer. See: https://www.safetymanualosha.com/is-fiberglass-a-health-hazard/ . Steam system balance is simple. All things being proper in the steam system, the smallest vent openings should be nearest the boiler, and largest the furthest away. Mains should be balanced for simultaneous filling to the end of mains. After that, it is an air vent balance task for simultaneous feed to each radiator, then if heating is still unequal look at the radiator size, that best matches the rooms btu loss. And on top of it all, wherever the thermostat sits, it should never be heated quicker than the average space. And it should be kept from being preheated by the heat anticipator, a lamp, or stove, or fireplace in use. In some cases, the balance problem is simply the thermostat is in the wrong place, or the system design is wrong initially or over time by building modifications. But if that is all correct and the problem still exists than suspect a malfunction control or an overlooked design or maintenance flaw. These things require maintenance and or repairs.
Hint: If you find a sagged or trapped pipe and cannot change it, install a manual drain or trap at the low point and handle it manually when it floods. Sometimes even a partially full main pipe can re-vaporize the liquid and keep the steam flowing. An old manual feed boiler in an old home that got overfilled accidentally was resolved with a 1/8" loose key vent this way without regrading all the pipe. Remember each type of steam design requires different knowledge and solutions, and wrong modifications make it complicated.

ccstelmo

Nesw guy here, although it sounds to me that you've really done your homework and thought this through I've been on a learning curve too.
How about the valve? Do they have valves? Or more to the point, does the problem radiator have a valve? When I recently acquired my one-pipe-steam-heated 80-year-old home, first I went after the air vents with vinegar as you did with the same success. Then I went after the valves.
What I found was that in three cases (nine radiators total in the home) the valve washer had detached from the valve body (or had disintegrated) and was lying on the seat. At the time I did not reflect on all the negative consequences implied by that condition but after reading about your travails I'm thinking that sludge could accumulate on a washer in that condition and that steam might intermittently overcome the weight of the steam plus sludge resulting in the symptoms you describe.
I spent a career in the pipe trades and still have all those tools to get stuff like that apart so it can be examined. You may not be able to do that. But it is simple:

Let the boiler fire down until there is no steam pressure. Shut off the electricity to it.
Take a giant wrench and uncouple the radiator from the valve by loosening that great big nut (counter-clockwise) Chances are you'll be generating a little water (maybe a lot of water) at this point so have a rag, a shallow pan, and a larger bucket handy to deal with the water.)
Move the radiator ever so slightly away from the valve (1/2" will do) (hope you're tough) then use the same wrench to turn the valve counter-clockwise enough so you can see in the throat of the valve. You'll be loosening the valve from the riser it is screwed onto.
BTW: These nuts have been on there for umpteen years, so you may need a cheater on the end of that wrench.
Whadayasee?
If the seat needs replacing you're now officially over your head, so get in touch with a pro.
In order to fire up the system again so you have heat in the home you'll have to put all this stuff back together. However, if the washer in the valve is in good condition you can just close the valve at this point.
BTW Two: Be careful of those threads! Don't cross-thread anything. line things up and start that big nut by hand before you put a wrench on it.
Good Luck from a sympathetic novice.

nicholas bonham-carter

You can also check the valve washer, by unscrewing the valve bonnet, without the trouble of moving such a heavy weight as the radiator.—NBC

wam525

Coming at this a bit late, but it seems there just isn't enough steam flow thru the bedroom radiator. Is the valve wide open? if not open it all the way, and take out the vent. If you get a lot of steam out the vent hole, then it's just a question of finding out where the resistance is slowing the steam. it's either the vent or the valve, and both are easily replaced.

Jackmartin

I am going to take a slightly different approach. First what are your pressuretrol settings,they should be
2 psig off .5 psig on. Steam systems especially single pipe, have got to breath in and out they are like a living creature. The most common problem I see and I really wish I was kidding,some brain dead idiots put the pressuretrol to 2 psig the cut in and cutout are together and think the system will heat better because ,duh, it's running all the time. I give you credit for your insulation but we have to go back in time, the dead men had to bring the temperature of your house to120 degrees f. This was the accepted rule at that time. They never insulated the pipes because they knew they didn't have to, the steam would heat any area it went through and if the system is operating correctly the call for heat on a regular basis would keep everything warm. I say this with all due respect to everyone ,but venting is not your problem, you stated you removed your air vent in your bedroom the rad blew air started to heat and quit. The supply to your room over so many years has sagged and it fills with water the steam cannot force itself against water it is a gas and water is exponentially heaver. Think, your house is very old, do you really think all the previous owners would put up with no heat, I can assure you customers don't put up with that situation without screaming the phone down. Please get a proffesional ,have him or her look at your system, they will trace out your piping and locate the point the pipe dropped. The fact you have a main going up with a tee on the bottom guarantees this is not a new problem. I have seen this done when someone thinks the pipe is too small for steam and condensate ,the dead men did not install the smaller pipe they knew what they were doing. The pipes have not been insulated for a hundred years, it is not a problem of heat being robbed by its environment. The fact you had no sight glass is very common in old systems, when your heating was installed sight glasses were not used Try clocks were the accepted method to check water levels, low water cutoffs were not installed ethier because they weren't considered nessicary for a house, commercial systems had a form of low water cut off not used for residential. Now, given the age of your house was your boiler at one time coal?? The thing with a conversion from coal to gas it upsets the installers apple cart. Boilers fired on coal kept steaming as long as the coal lasted, so every pipe in the house was always warm, gas causes problems on old systems because it cycles on and off this contravenes the original design, that is the reason your pressuretrol has to be right on the money, I applaud your effort to get your vents working but in my experience they never work correctly because no matter how hard you try, some calcium is always left and over time plugs your vents again. When you have a pro look at your system I am pretty sure they will recommend Hoffman No 1 vents. I am called to consult on steam problems because I am freaking ancient. I have seen what people who don't understand steam do to a system. They " fix it" by changing it into something they think they understand, steam help is so easy to obtain now ,no one should make stupid mistakes. I would suggest you get The Lost Art of Steam Heating excellent book and download Getting the Best from Single Pipe Steam written by Gerrety for the New York housing department the man was brilliant, you can also download Jacob Myron's book on steam heat, excellent book, and you get it for the price of printer paper. All the best from frozen Canada I hope you find the solution soon, have a Merry Xmas and a Good New Year.
Cheers Jack
Dan said it best ,if you think steam is not a hands on heating system you should think again it requires constant attention. That is why hot water became popular it didn't heat your house better, it was not a hands on heating system. In the event your boiler was coal the home owner banked it every night and in the really cold weather was up at four in morning to do it again, that's what my old man used to carp about, so sad to bad, try being homeless in Wininpeg when it drops to forty bellow.

Mad Dog_2

As thick Fiberglass as u can fit. Owen's Corning brand is the highest quality.   
Never use rubber on steam it gets cooked and brittle. I learned the Hard way insulation is really just the icing on the 🎂 cake, but the "cake" must be properly "baked"  aka in good working order, i.e.,  insulation is not the solution to under sized piping, poor venting. Wet steam et cetera.  It should be added only after everything squared away. Mad Dog

ccstelmo

NBC's right. The bonnet can be removed and the stem and washer examined that way. But ... The bonnet nut on your old valves is most likely a square bonnet nut. It's been on there for umpteen years. It ain't comin' off of there without a fight and, most likely, without ruining the bonnet nut unless you happen to have a square socket or square wrench the precise size of the nut. The nut'll get wrecked! I did eventually get my square bonnet nuts to turn but with a wrench I had to fabricate and with a cheater 30" long. Just turning the valve body itself 180 degrees so you can see into it is the way to go.

jsware4

I had similar problem, 2 radiators not heating up. They were both at the end of long runs. I solved the problem by adding a 2d vent to each radiator. This is a 1 pipe steam system, with pretty clean piping, Cast Ray radiators, Vari-Valve vents.

marciacubed

Thank you all for the feedback and assistance, and I apologize for going silent for awhile. Long story short, I jacked my rad up as far as I could with a random board and an old rolling pin as a fulcrum, and that helped some, but still not perfect. We made it through the worst of the winter, but the old boiler is now "toast", presenting me with an enormous project of replacement, preceded by abatement of the old asbestos pipe insulation, and installation of a chimney liner. And I don't expect any of that to fix my original problem. Anyone know a good steam heat contractor for Connecticut's Northwest Corner?

dabrakeman

When you have a T- drip below the radiator like you have the supply pipe ( the runout from the main) should be pitched away from the boiler. I.e., with this drip leg arrangement your runouts should be parallel flow not counterflow. Thsi is different from most peoples systems but every single radiator in my home is piped in this manner. It is possible with raising the radiator that the runout now goes from parallel to counter creating a low spot and water collection somewhere within the runout. Obviously the drip needs to be pitched in the opposite direction allowing condensate flow back to the boiler.

Big Ed_4

That problem radiator needs to be vented as a main . Either install a King Vent on the supply . Or tap in a second vent and first try two Varivalves . There may be a tapping already up there for a main vent, maybe it was removed and plugged . The original installer seem to know what he was doing . Adding a drip line tells me he was running a main ...

Waher

Someone else on the forum had posted this before in a somewhat similar situation.