cmcbain
Nuclear
- Dec 8, 2009
- 51
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?
