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Up Topic Welding Industry / Processes / Pretensioned bolt inspection (hex bolts)
- - By jwright650 (*****) Date 11-19-2015 13:19
I know that others here have run into this scenario before so I have to ask how did you handle it?

Called to a job to perform a structural inspection and discover several bolted shear frames that are called out to be pretensioned, but the hex bolts are already in and I wasn't there to watch the installation, there are no match marks on the bolts or steel, only tick marks beside each bolt indicating that someone has tightened each bolt.

How does a person satisfy everyone that these bolts were properly tensioned after the fact? Should I insist that these bolts come back out, and be re-installed?
Parent - - By jwright650 (*****) Date 11-19-2015 17:00
Update:
After speaking with the contractor today, he is having the bolting crew loosen those connections and pre-tension during my next site visit so we can make sure it was performed per RCSC 9.2.(provided the used hex bolts are visually OK)
Parent - - By In Tension (**) Date 11-19-2015 17:35
I know next to nothing about bolting but some Engineers have led me to believe that reusing pretensioned bolts is a no-no.  Is this not correct?  Are they reusable so long as they maintain form/fit/function?  I wish I knew more about the subject.  It's handy knowledge.  Almost signed up for the bolting endorsement if only to force myself to learn something new.  The endorsement itself would be pretty useless though (for me, anyway).
Parent - - By jwright650 (*****) Date 11-19-2015 17:51
RCSC 2.3.3 says A490 and Galvanized A325 bolts shall not be re-used, with EOR approval, black A325 bolts are permitted to be re-used.
Parent - By In Tension (**) Date 11-19-2015 18:48
Gotcha.  I knew that was the case with A490 but hadn't run across the situation with black A325.  Thanks for the info.
Parent - - By welderbrent (*****) Date 11-19-2015 22:42
John,

I have on a couple of occasions had the erector RFI the engineer and get them to change to a snug tight.  There is often no true need for the 'Turn of Nut' or any other tensioning method unless we are dealing with slip critical. 

Also, they should have performed testing with a skidmore or similar test equipment.  Was this done?  If not they have two strikes. 

My questions:

1) what was called out as the tightening method?
2) who witnessed bolt storage and condition prior to install?
3) who witnessed the testing to prove installer ability to get the correct tightness?
4) are they indeed A325 bolts? (you mention the code but not actually state their grade)
5) are the nuts correctly installed? (correct side exposed to verify nut grade)
6) are washers used where needed?  How do you know...you can't see the hole size?
7) were the bolts installed correctly?  No hammering, etc.
8) most of the time, throw them away and start over.  Too many variables after the first use and you do need engineer approval to reuse.

He Is In Control, Have a Great Day,  Brent
Parent - - By jwright650 (*****) Date 11-30-2015 12:03
EOR wants these bolts pre-tensioned, they are bolted moment frames. It was requested that I return tomorrow to witness and inspect the installation of these bolts.
Parent - - By 803056 (*****) Date 11-30-2015 14:02
Make sure the contractor doesn't try to relubricate the bolts and reinstall them.

Al
Parent - - By jwright650 (*****) Date 12-01-2015 11:49
They have been rained out for today....and probably the rest of the week.
Parent - - By 803056 (*****) Date 12-01-2015 14:11
Isn't that the way it usually happens?

Best regards - Al
Parent - By jwright650 (*****) Date 12-01-2015 17:45
:wink:
- By 46.00 (****) Date 02-14-2016 22:48
From my last contract,I learnt a lot about boulting. It was indeed an education and something I knew little about beforehand!
Up Topic Welding Industry / Processes / Pretensioned bolt inspection (hex bolts)

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