Friday, January 2, 2015

A Little Excitement to Kick off 2015

 Did you ever wonder what would happen when the propane company tops your tank off to nearly 100%?


 There's a darn good reason they are only supposed to fill it to 80%

Jeff and I were discussing something in the house when all of a sudden we both said, "I smell gas!". It was going to reach 55 degrees today in Seagrove, NC, so we let the wood stove burn down and turned on the Rinnai gas heater instead. We quickly went out to see if the vent was clogged. It wasn't, so we hurried out the back door to the kiln shed to find our 500 gal. tank, in the backyard, spewing propane from it's overflow valve. My first thought was call 911, because I was scare sh#$2tless that it would blow... Jeff (being more reasonable) called the propane company. We had propane delivered on the 31st and they thought it was over-filled. They said don't call 911 and they would send someone out to blow it off.


 It took about an hour for the service guys to arrive. The valve started to freeze from the gas releasing, which eventually slowed the spew. I liken this valve to the pressure release valve on my pressure cooker. I imagine it's basically the same thing... on a much bigger scale.



It took what seemed like forever to bring the level down to the normal fill of 80%. The gas smell was horrendous. They aren't sure exactly how many gallons they had to blow off, but they will credit our account for 50 gallons, which translates to about $79 at $1.59 gallon. The comical thing about this event (and you always have to find something funny in a scary situation) is that the service guy said, "Why don't you turn on the kiln and fire some pots with this fuel we have to get rid of?"

If he only knew.

16 comments:

  1. wow, that is really scary, why did the valve freeze when the weather wasn't that cold? I remember hearing of places in Tahoe blowing up when the gas line was tweaked by heavy snows and the gas would follow the gas liine into the homes, but your situation is just darn crazy.So glad you are ok.

    ReplyDelete
    Replies
    1. lp gas freezing has nothing to do with outside temps... when we fire our raku kiln our small tanks often start to freeze (even in warm weather). We douse them with water to keep the gas flowing and the temp climbing. It's a weird phenomenon that someone else can explain better than me. The overflow did it's job (thankfully!).

      Delete
    2. Once a propane appliance is actively in use, the liquid propane in a tank or cylinder begins to boil. The propane vapor, as boiled off the top of the liquid begins its journey downstream to the point at which it is used. Before making its way to the LP Gas system piping, it passes through the regulator where its pressure is reduced to a usable level. Keep in mind that the regulator will only deliver a constant pressure on the outlet side while inlet pressures can significantly vary. As the propane passes through the regulator, it expands (resulting in sub zero temperatures) and causes the regulator to gradually reach the extremely cold temperature of the propane vapor passing through it. Depending on the temperature and humidity of the surrounding air, the regulator will produce condensation, much like that of a frozen mug or glass taken out of a freezer.

      Delete
    3. found on internet, was wondering since we have a propane tank and I want to be safe

      Delete
    4. In all the years I have fired a kiln or heated a house with propane, this is the only time they have overfilled it. I am glad that it happened when we were home and not traveling!

      Delete
  2. Compression heats gasses, decompression cools them.That's why you refrigerator works.Glad it wasn't any more exciting than this.

    ReplyDelete
    Replies
    1. Thank you for the explanation. I will have to remember the fridge analogy.

      Delete
  3. I am sure releasing all this gas into the atmosphere wasn't great for the environment, let alone wasteful.

    ReplyDelete
  4. Last year I started a raku firing. Within the first few minutes the hose and valve began to freeze. I shut it down and let it defrost. I restarted the raku and again the valve and hose froze. I unhooked the hose and burner and took the tank to the propane company. They told me the same thing, that the tank had been over filled. They blew out the excess propane and told me that had I continued firing there was a possibility of the tank exploding. I had this tank filled at a gas station. Now I only fill at the propane company. Lesson learned.

    ReplyDelete
  5. Just glad that you guys are okay and were there to deal with it.
    I've been dealing with LP Gas most of my life; I've seen this happen in small tanks but never with big ones.
    What a way to start the year!

    ReplyDelete
  6. Oh dear...so glad your adventure (?) was all figured out and dealt with successfully.

    ReplyDelete
  7. What you described is a major violation of NFPA Standard No. 58, the LP-Gas Safety Code which is adopted as North Carolina state law.

    Your second photo clearly indicates the LP-Gas technician doesn't understand the fundamentals of a stationary LP-Gas container. He is using the liquid withdrawl connection to vent a full container. Under NFPA 58, the LP-Gas should be recoved using the hose on his bobtail truck so it's not discharged to the atmosphere. LP-Gas is heavier than air so if your kilns were operating he was creating a situation for a flash fire and everyone in the picture becoming thermal burn victims.

    In the future I would ask the LP-Gas supplier if their personnel have completed the Certified Employee Training Program, which is administered by the National Propane Gas Association. If the supplier says "huh" or "no" I wouldn't use them. Good luck and I am glad it worked out in this case.

    ReplyDelete
    Replies
    1. Our kiln was not firing when this occurred (thankfully!). I too was concerned about so much gas being released into the atmosphere. All of the lp gas suppliers in this area are owned by the same company, we might get different technicians but I am not sure they would be trained any differently.

      Delete

Don't be shy, talk to me... I won't know your out there if you don't!