×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Turnbuckle, but for compression (i.e. clevis-ended jack screw)

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?

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

Found these on McMaster. The description for the one with clevis ends specifically says can be used to push or pull loads: Mcmaster

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

Ratchet load binders are also called 'steamboat jacks'. That phrase may get more response from local suppliers.

Mike Halloran
Pembroke Pines, FL, USA

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

(OP)
Nice. Those aren't the size I need but maybe I'll be able to find additional sizes somewhere else.

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

You could try searching with the term "telepost" or "adjustable pipe stanchion"

STF

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

Acrow prop?

"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)

"Nice. Those aren't the size I need but maybe I'll be able to find additional sizes somewhere else."

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)

(OP)
The size I'm looking for would be around 30" long and have 3/4" dia pins in the end clevises. It would be rated for at least 1000 lbs of compression load.

RE: Turnbuckle, but for compression (i.e. clevis-ended jack screw)

(OP)
Tmoose: There are some other column buckling calculators around that will let you go to a smaller diameter, like this one:

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)

Looks like maybe you could just buy something from these guys.
http://www.pipingtech.com/products/ptpcat/support/...

==========

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...

=========

How important is the adjustability?

http://www.miroind.com/wp-content/uploads/2016/07/...

https://ae01.alicdn.com/kf/HTB1EIyRKXXXXXahXpXXq6x...

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources