Turnbuckle, but for compression (i.e. clevis-ended jack screw)
Turnbuckle, but for compression (i.e. clevis-ended jack screw)
(OP)
I'm working on replacing a 4" ball valve in a run of horizontal pipe. All structure that could be used to attach supports for the weight of the valve is below the valve. The engineer who originally designed support for the valve used 2 generic McMaster-Carr turnbuckles from the to support the valve... from underneath.
To me, that seems like a bad design. Admittedly, the turnbuckles are rated for 6000 lbf each and the valve only weighs 500. However, everything I know about turnbuckles tells me that rating is for when the turnbuckle is in TENSION, not compression. There's just not enough material in the body of the turnbuckle to keep it from buckling.
So, has anybody ever seen something like a turnbuckle that is designed for compression? My first shot was a jack screw, but I'm not finding any that have clevis ends. The supports are perfectly vertical and there's plenty of lateral support for the piping so a pin-pin column support is adequate and convenient.
Another option might be to throw away the existing turnbuckles bodies and replace them with something like an internally threaded tube. But, why design why you can buy?
To me, that seems like a bad design. Admittedly, the turnbuckles are rated for 6000 lbf each and the valve only weighs 500. However, everything I know about turnbuckles tells me that rating is for when the turnbuckle is in TENSION, not compression. There's just not enough material in the body of the turnbuckle to keep it from buckling.
So, has anybody ever seen something like a turnbuckle that is designed for compression? My first shot was a jack screw, but I'm not finding any that have clevis ends. The supports are perfectly vertical and there's plenty of lateral support for the piping so a pin-pin column support is adequate and convenient.
Another option might be to throw away the existing turnbuckles bodies and replace them with something like an internally threaded tube. But, why design why you can buy?





RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
Mike Halloran
Pembroke Pines, FL, USA
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
STF
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
"I love deadlines. I love the whooshing noise they make as they go past." Douglas Adams
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
I had something in mind (we use them in construction all the time), but I guess the size wouldn't be right.
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
the smallest pipe it would let me enter was 2", but that was good for 20,000 lbs
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
Link
I am pretty certain that a 3/4" dia, 30" long pinned end column won't buckle under a 1000 lb load (I did use the calculator to double check). I am more concerned with the threaded portions of a standard turnbuckle body. The way that's designed, with a short solid portion and two thin sections extending out from it, says tension only to me. I spose I could throw the McMaster CAD file in the ol' FEA solver and see what happens.
RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)
http://www.pipingtech.com/products/ptpcat/support/...
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Could maybe do something like this using steel from out in the yard, and even re-use the turnbuckles in tension?
http://www.eberliron.com/public/images/product/rts...
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How important is the adjustability?
http://www.miroind.com/wp-content/uploads/2016/07/...
https://ae01.alicdn.com/kf/HTB1EIyRKXXXXXahXpXXq6x...