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VALVE STUCK OPEN POSITION

stopgogostopgogo Posts: 25Member
Velan valve 14" stuck in the open position on a main steam distribution system. It was exposed to a leak which in turn created humidity in a hot manhole enviroment and over time seized the operating valve in the open position.
We have attempted to muscle the valve with cheaters lube/grease and 10lb sledge hammers to try and unfreeze the valve but to no avail.
Today I attempted to undo the valve stem and use a torch rose bud to heat up the upper portion of the valve that drives the stem ... also, no avail.
I used a compression tank with pneumatic gun to vibrate the valve and introduce the oil and lube ... but still no matter how much muscle we attempt to force it with the darn thing wont move.

I am thinking of using a wall anchor and a come along next perhaps with a 3rd person using a sledge at the same time.....

As you can see this is been an ongoing problem for us.
The valve stem is stainless and the operating mechanics that drive it are forged steel i believe.
Corrosion resistance or electrolysis ?

Any help would be appreciated.

Comments

  • Jamie HallJamie Hall Posts: 10,469Member
    Almost certainly corrosion. On the Velans I find that operating nut is grey iron, and the stem stainless -- there isn't enough electrolytic difference there to create a problem. But it is quite possible that there has been enough corrosion damage on the nut that it is well and truly frozen to the stem.

    I don't really have any bright ideas. You can try heating the nut, but it sounds as though you've done that. Can you get any movement on the hand wheel at all? Either way? If so, rocking it back and forth -- even a few degrees -- may eventually get you some play.

    I'd be rather careful with both impact and excessive torque. It is possible to break those things...
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,802Member
    I would call Velan and see if they have any good ideas on how to approach it. What you have tried is probably what most of us would do.

    Is this valve on a live steam line or are you shut down?

    No fun pulling a 14" valve but is that a possibility to take it to a valve shop and get it repaired?
  • nicholas bonham-carternicholas bonham-carter Posts: 7,829Member
    Is this valve really needed?—NBC
  • Intplm.Intplm. Posts: 753Member
    Have you tried hitting the top of the stem?

    If you can remove the valve handle and put a pipe nipple over the stem leaving just enough room to put the handle back on. When you do that, then you can hit the top of the stem as hard as you dare. The nipple wedged between the handle and the valve body will help reinforce the valve stem limiting the chance that you will bend it.

    Hope you can shut the system off first.

    If all else fails, what's in the future is a new valve installation which I am sure you are trying to avoid.
    Exercising the valve in the future is a good idea. If you need to replace it, be sure to install a valve primer bypass.

    This is a tough one . Good luck.
  • stopgogostopgogo Posts: 25Member
    Thanks for all the bright answers. I will try the Nipple over the valve stem method as a last resort.
    I was thinking two come along's on opposite sides of valve and two anchors so that i can put a tremendous amount of pressure on that stem... just not sure if that is a safe attempt due to the valve being on a 125psi steam line....eeeek.

    Thanks again. Love this forum.
  • Leon82Leon82 Posts: 615Member
    The 2 come alongd sounds better that the one as you will get somewhat even pressure vs a risk of lots of pressure in one direction
  • FredFred Posts: 7,863Member
    It is craaaaazy to put an inordinate amount of pressure on any valve that has 125psi of steam behind it!
  • mikeg2015mikeg2015 Posts: 795Member
    One of those items that usually goes on to a
    A shutdown list.

    While you are fighting this,
    Resources could be better used on predictive and preventative maintenance to avoid those types of issues.
  • stopgogostopgogo Posts: 25Member
    here are the pictures of the valve stem drive which seems to have corosion set mixed with old lubricant that was present inside. i cut the mechanisam in half and had to beat it out with a sledge. it is solid sealed shut!!
    this is for education purposes so enjoy the findings. thanks gents
  • stopgogostopgogo Posts: 25Member
    this is a smaller valve 4" but the issue is the same and the enviroment similar to the 12". I wonder if I can use the compression lube fitting to pump in a water soluble lube like wd40 since the regular lube wont penetrate due to the thick viscosity. will inform in the next few weeks to come. i will science this
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