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residential steam boiler relief valve question

ron
ron Member Posts: 339
edited March 16 in THE MAIN WALL
watching "Near-Boiler Piping in Steam Heating Systems" on youtube. Around 12 min mark it was mentioned

the 15 psi steam relief valve is a evil jack in the box and dumps entire boiler steam load at once and will put 250°F steam into the boiler room instantaneously, will displace oxygen and kill you, which is why you always leave the boiler room door open when in there if you are also in there...

For a single family home (not an apartment building) that has a steam boiler... I think I remember seeing one at a friend's house years ago but that was before my caring anything to know about steam or hydronic heat, his steam boiler was in a small utility room in the center of the finished basement that had couch and tv and where we had watched superbowl... oops the "big game"...

but after listening to the youtube vid and the potential dangers of steam and about leaving the boiler room door open if you're working on the boiler, but what's the deal with residential installation... where you're not working on the boiler but watching tv and spending time in a closed area where the same danger is still present should the steam boiler get problematic and pop the 15 psi boiler relief valve into that closed area where you are sitting on the couch? do they run a pipe from the relief valve to pipe the steam to outside the house?
Mad Dog_2

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 20,812
    One reason I select the YouTube videos I choose to watch very very carefully... unless I am looking for laughs.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    GGrossMad Dog_2
  • ron
    ron Member Posts: 339
    ^^^ not sure what you mean?

    if my question didn't come across, steam boilers can vent boiler steam into a small area and be deadly. I thought I recognized a residential steam boiler in a house in a finished basement - how is that risk dealt with or is it just ignored because it doesn't happen frequently? I do remember asking the guy when I heard the steam boiler kick on, it was noisy, what do you have and he said steam heat or steam boiler that's normal and he said he knew nothing about it. Looking back, having been educated by a heating help youtube vid (which I consider credible) is the homeowner and family's life in danger by having a steam boiler in a finished basement? If it should ever dump steam, or am I not aware of some boiler relief piping?
    Mad Dog_2
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,236
    A lot has to go wrong for that pop-safety steam relief valve to open. My point in the video is that a steam relief valve doesn't open just a bit, as a hot-water relief valve will often do. It opens fully and instantly and my advice in the video is to leave the boiler room door open when working on the boiler so you don't find yourself in a closed box with the steam suddenly exploding out of that valve. It's a be-prepared thing and I had big boilers in mind when I said what I said. I wouldn't be concerned about a well-maintained, residential steam boiler in a finished basement. Thanks for asking.
    Retired and loving it.
    ethicalpaulErin Holohan Haskellmattmia2Mad Dog_2
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,236
    Retired and loving it.
    Mad Dog_2
  • ethicalpaul
    ethicalpaul Member Posts: 4,445
    edited March 16
    Tell him the noise isn't normal. He can check the water level before each football game and he'll be fine.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • ron
    ron Member Posts: 339

    It's a be-prepared thing and I had big boilers in mind...

    so now i'm curious what a regular sized residential boiler relief valve popping off would be like.


    the trash to power plant about 1000 yds or less from where I work, has often let off steam for whatever reason, and more than a few times it is deafening outside for 1/2 an hour.
  • ethicalpaul
    ethicalpaul Member Posts: 4,445
    I'll have to make a video now
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • retiredguy
    retiredguy Member Posts: 719
    edited March 16
    A residential steam boiler has to have a fairly massive control failure for the steam safety valve to pop open and dump steam into the space it occupies. If the boiler occupies a corner of a normal sized basement, the amount of released steam would not be dangerous to your life unless the pressure in the boiler became extreme, or as we call it, a run away which rarely happens to a yearly serviced boiler, serviced a competent boiler tech. The reason to leave the basement door open when you are in that space is for when there is a catastrophe or when the basement is very small. If there was enough steam to completely fill the boiler room, there would be no oxygen to breathe and you would suffocate. To be safe in that case you need to stay below the steam cloud if possible and get out of the basement as fast as you can. Leaving the basement door open gives you a visible access to exit the space.

    On a very large high pressure steam boiler, with steam pressures in excess of 100 PSIG, when those safety valves open cover your ears. It will sound like a shot gun firing near your head.

    Here is something to remember; 1 cu ft of water at 212F boiling point will expand and instantly occupy 1700 cu ft of open space. So, make sure that you have your steam and hot water boiler serviced yearly by a competent boiler tech.
    my 2 cents

    Mad Dog_2
  • Jamie Hall
    Jamie Hall Member Posts: 20,812
    It's not at all uncommon for the pop safeties on power boilers to release -- in fact, the system is designed to do so, in case of a sudden reduction in load. However, unless I am sadly mistaken, it is rather uncommon for them to discharge into a confined space. Further, again unless I am mistaken, they are designed with the power capacity of the boiler very much in mind and a controlled, if high, release rate related to that, which limits the potential pressure rise, but is not so fast as to allow a precipitous fall in pressure (an example of a situation where bigger is very much NOT better!).

    Contrasted with an uncontrolled high pressure steam release, such as from a failed pipe or part of the boiler. In those instances the pressure drops fast enough to flash all or a good part of the water in the boiler all at once -- and the results can be a bit hard on anyone nearby.

    Parenthetically, this is the same kind of phenomenon -- with the added hazard of combustion -- involved in explosions of tanks containing a flammable but high vapour pressure liquid (as it might be LP gas -- or vinyl chloride) -- and is why a controlled release, say by punching a hole in the side of such a tank which is overheating and flaring the escaping gas is preferable to sitting back and waiting for it to fail abruptly.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,236
    Jamie, I had in mind the many NYC boiler rooms in very old buildings where the boiler takes up nearly the entire room. The General Society has two brick-set boilers from 1890 that are out of service. Each is 20 feet long and 10 feet square. You have to step outside the room to change your mind. It’s that tight. I agree with you on more-modern systems. 
    Retired and loving it.
    Mad Dog_2
  • Jamie Hall
    Jamie Hall Member Posts: 20,812
    They certainly did do things differently in 1890! They were still blowing up steamboats and railroad engines, too. Much more fun!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Mad Dog_2
    Mad Dog_2 Member Posts: 4,407
    edited March 17
    I've seen a few runaway boilers in my day. Two stand out. First one, was a residential Burnham Gas Steamer installed 10 years prior. The HO said the installer told him "..you don't gotta do nuthin' ta diss...maine'nt free!" I got the call through Heating Help. The man was hearing alot of sloshing and banging and he wanted it checked out....The boiler was running when I got there and pressure was up around 30 P.S.I. !!!!!!!!!!!! MAXED OUT, and there was no visible water line. LWCO Light was on.... REACHED FOR THE SWITCH and told him to GET OUT NOW!! He ran out of the room, but his ghoulish curiosity soon brought him back to see why I was still in boiler room. I'm the type that goes down with the ship...ha ha.... After about 20 minutes, the water level came back and I heard a huge waterfall inside the boiler and piping. The pressure had only dropped about 2 PSI. Boiler fired again. Interesting....I killed switch again and carefully hooked up a hose to the lowest boiler drain and thankfully, he had a sewer house trap 5 feet away, so I popped the fit-all plug and put hose deep, 15 feet, in to Street side of trap. I opened very slowly and cracked the valve...and knew I was dealing with some dangerous steam pressure. It was releasing the HP Steam and condensate and gradually the PSI
    dropped. When I knew the boiler was empty & there was no Pressure, I lifted the arm on the 15 PSI Relief valve and didn't even get any steam vapor...hmmm??? I took off the Relief piping and screwed off the valve...TOTALLY 100% blocked....nipple in to boiler...100% blocked. (I have the pics will post someday) Now, I take off the Pressuretrol & pigtail and nipple in to boiler. 100% blocked!!!! The ONLY thing that prevented this BOMB...from blowing the house off its footings and killing everyone, like the old days, was the Probe LWCO that was - THANK GOD!!!!!! - still working after ten years of no maintenance. The boiler would run, run, run until all the water backed out of the boiler and the LWCO would kill power. If this LWCO had failed to work (in a few more years...who knows) it would've made the front page of Long Island Newsday. I felt very proud and important that day. I DEFUSED a bomb!
    Second, was The Little Portion Franciscan Monk Friary in Mount Sinai Long Island, a Beautiful mountaintop 70 acre retreat house and bakery. I got this through Heating Help also, but was also referred at the same time by my Great Latin Professor, "Granddad" and mentor, A.W. Godfrey - Legendary Stony Brook Latin Professor (RIP Magister!!!!). So, I had the "street cred" established going in..that's Golden. First thing the Brown-Robed Head Monk Brother Clark did was hug me and thank me for coming! I said let's go see the boiler room. He lead me through the great-smelling bakery where they would start at 3am twice a week and make the best bread you ever had - 4 types. proceeds went to the local poor. Locals came from miles around and in 3 hours hundreds of loaves were gone...all on your honor..make your own change...money in the jar. Next to the oven was a trap door leading to a dark room..there was a rickety 125 yr old wooden ladder, that I had to shinny down ten feet. The pit was about 10' x 15 feet. Boiler was running...oil steam HB Smith??? I put my mag lite on the pressure gauge and it was roaring away at 25 PSI and climbing fast. I looked for the Boiler switch but was nowhere to be found... Brother Clark had no clue where it was. He was brand new here and fresh in from The Franciscan Order in California. I tried to rip the wires off the oil burner TT terminals, and did, but the mad puppy kept roaring away (dead short?) like a freight train. No time to run up the VERY-PRE-OSHA-Ladder. With two hands, I grabbed the BX to the burner and yanked as hard as I could in the very poorly lit pit. Some sparks flew, Brother Clarke jumped back, but I stopped the Titanic! Whew. I suggested we take a blow outside and let her cool down. Came back an hour later, and did the same thing as the other boiler.

    No Probe LWCO to save the day here, The #67 LWCO was totally clogged and NOT working , Both pigtails, including manual reset, were 100% clogged and so was the 1.5 Million BTU 1 1/2" Relief valve and nipple in to boiler. Another Bomb DEFUSED. I condemned this old, leaking monster loaded with asbestos too! Luckily, it was the end of the heating season. As we sat down in the communal Kitchen with Brother Clark and a Facilities guy from Stony Brook who was trying to guide him, they had had several boiler replacement quotes on the table. Since, I had come HIGHLY recommended from two very serious sources, AND saved the Friary and all its inhabitants from blasting off in to the Nearby (100 yards) Long Island Sound, they Trusted me: "Matt...can you do this job for $90,000 ????" I almost fell off my chair. I calculated quickly what the boiler would cost and labor in about 3 seconds, and said: " 90 THOUSAND????? is that what the others are quoting you???" Yes, that the lowest one!" "I WILL DO IT FOR 50 THOUSAND!!!!" They jumped up and starting going crazy and were SUPER relieved. They thought the Friary was DONE FOR..with this 90 THOUSAND dollar job. They had been sweating it out for weeks trying to raise the funds. They wrote me the 50% Deposit check right there. It was a very difficult but great job and we got very close with Brother Clark, Brother Leo, Brother Funston (My End of the day, Corona with Lime 89 yr old buddy!) and Brother Tom, a recent, former - pretty famous - soap opera star that you would recognize immediately. It was around the time Mom was dying with Cancer and everyone here at The Wall were following her progress and this neat job. Mom would take a ride with the Triple Crown boys and spend the day with the Brothers praying in The Sanctuary, having Coffee and life discussions, and walking the grounds with Matt Jr 6 years old. They were Episcopal Franciscan Friars (monks in Brown robes) and Mom, Colleen a DEVOUT!! Roman Catholic but it was all good, They loved us, we loved them. So, in conclusion, Steam relief valves blowing off are a sign of a problem and can be very dangerous, but when a Boiler and system are TOTALLY neglected, you might as well just have a PLUG in place of the Relief valve. Take everything apart once a year and this will NEVER happen to you. Mad Dog
    CLambmattmia2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 4,407
    The Plumber (and Boiler man) Truly DO protect The Heath of The Nation! Be VERY proud of what we do everyday. Mad Dog
  • mattmia2
    mattmia2 Member Posts: 7,342
    I'm curious about how that boiler got out of the pit and the new one got in there.
  • Mad Dog_2
    Mad Dog_2 Member Posts: 4,407
    edited March 19
    Ha ha..I was hoping you asked.  It wasn't our first rodeo with huge boilers in a deep pit.  I often marvel when moving huge boiler sections up & down , how the methods have not really changed in 150 yrs...We split up the sections, had long, heavy planks leaned up on a slant against the wall pit.  Tied heavy rope, to them and Tied it off to the hitch on the boiler removal crew's huge truck.  We had to snake rope through a few doorways, past the ovens, through the window to the truck.. there were like 10 huge sections. The truck didn't have much of a runway till you'd hit the woods, but we got em up.  Went down the same way.  Flawless..no damage to Terracotta tile kitchen floor.  We did another doozy..that no one was up in Sea Cliff (Picture Great Gatsby Victorians) No one would touch.  The owner said the last guy opened the skinny door in the home's hallway, looked down 10 feet to the boiler and said; "No! No! No!...I heard about this boiler.".and he backed out quickly. Even the guys at the local supply house knew about it  ."Be careful buddy...that boiler in the pit is cursed and no one in their right mind is taking it on!"  Right up my alley.  I had to double my normal price because it was in a tight pit in the middle of a historic home.  It was an old officer's quarters from Long Island's 🏝 Camp Upton from WW I where Black Jack Pershing's American Expeditionary Force trained before hitting The Continent to take on Hindenberg and Ludendorf.  It later became Brookhaven National Labs where Dan and I sat at An Energy Efficiency Roundtable with Director Tom Bucher, Robert O' brien, and Kevin Beckett, and another field guy who was blowing my mind with boiler knowledge  ..what was his name Dan? That was..2004? 
    Any-who, this house was lifted off its foundation, pulled by U.S. Army Mules and loaded on to a barge, sailed West on the beautiful Long Island 🏝 Sound and they did the reverse in Historic Seacliff, placing it on a scenic overlook.  The owner Mark was a really cool wealthy man who appreciated what was at stake.  Basically, he told me no one will touch this not even the local 150 yr old plumbing company.... my family needs heat..The Job is yours.   Charge me whatever you need to.  This was RARE.  We really enjoyed doing the job.  It was two pipe Vapor and the water line was very close to the first floor radiator supplies.  Piping and low pressure would be Uber Critical.  I'll post pictures again soon...I went Very high w Double Drop header, used a Mercury (boy I miss them) 16 oz vaporization.   I would up running the system at about 10 ounces.  I cleaned the system for days...I had two rads that would not heat...Scratching my head I piped in a viewing port to  see how dry the steam was.
    I even called my Buddy, The Great Steamhead for advice...."Mad.Daaawg.(in his Southern Maryland drawl) I think you're almost there...keep cleaning her..."  6 hrs later the whole house 🏠 heated.  Voila! 
    Learned alot on that one..  tuition!  But I was being paid handsomely for my dogged determination and rep thru HH and Dan. I would do a boiler like that everyday for the rest of my life, hard, challenging and fun. I repiped the whole boiler room for easy maintenance.. the one good point was the water heater was down the hall in a closet.  We actually built a large drywell in the pit so you didn't need the bucket brigade no mo' and no greasy black hoses dragging down their hallway. Mark wrote me a glowing testimonial you can see on my ad here. I didn't hear a thing about this boiler for 15 years...all good..New owner tracked me down...needed a little cleaning.  Spent 3 hours flushing, great conversation 👌 haven't heard from Mr Bobley in about 5 yrs.  His brother made a great Documentary on the Catskills and how they viewed "Flatlanders"  strangers from downstate.   Very cool  Roger Bobley...look it up on Youtube...If you've spent anytime in the Country especially The Catskills, you'll LOVE 💘 love this...Andes, Margaretville, Fleishmans..I actually recognized the people from town.  Another boiler in a Pit..Queens NYC..These houses were built like 1950.  The boilers were in a trap door in the middle of the Kitchen. The guy was National Guard whom I met in summer training at Camp Smith (Near Peekskill diagonal across The Mighty Hudson from The West Point. He bought a Skant Fin Steamer.  It was only about 125 K in so it wasn't too bad.  We lowered on rope.  Rigging is everything with large boilers. Gotta know your knots (No Gordian Knots!).
    I would be hard pressed to find the crew I had to take on and fix these wild jobs.  My Father in Law Don (US Navy Vietnam Era) late 1960s.  He was super smart w a Chemistry Degree from Stony Brook and ran the Nassau County Dept of Health Water Bureau for many years - top dog.  He always worked a second job 7 days and nights a week.  Bowhunting Season was HIS time.  He " retired" at 55 with a great pension and I put him to work for another 20 on my House renovation and Triple Crown 👑. 
    Never a plumber but he did everything Competently and Carpentry, Masonry, Electrical and auto repair exceptionally.  Between, him and Long Island Heating Legend, Jimmy The Gent Burke, we took on all comers...we always won in the end...and so did the customers! It was a Glorious War!   Don's 78 and still humping up trees w the bow  Jimmy is 66 and Semi-retired in Florida.  Me, I'm going full speed..damn the torpedoes!  Mad Dog