Bolting sequence
Bolting sequence
(OP)
Does anyone have a copy of the bolting sequence for a 280 bolt fllange?
it's tiresome to manually work out this sequence.
it's tiresome to manually work out this sequence.
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RE: Bolting sequence
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RE: Bolting sequence
RE: Bolting sequence
What is tedious from the specification standpoint? The foreman of the millwright/mechanical crew tightening the bolts might get tired writing every bolt on the checkoff drawing, and each intermittent torque value - remember, as shown above in the procedure you must NOT fully tighten any bolt by itself. Each bolt must be partially torqued in alternating sequence around the bolt circle:
12 Bolt Flanges and More
* First round – 20% of final torque (flange sequential order)
* Second round- 40% of final torque (flange sequential order)
* Third round – 80% of final torque (flange sequential order)
* Fourth round – 100% of final torque (sequential order)
* One final time - clockwise or counter clockwise sequentially around the flange.
So, you have 280 bolts times five rounds of torquing in sequence. Tell the crew to get busy. Give the foreman a calibrated torque wrench and the chart of all 280 bolts with the proper sequence of each bolt drawn on it and five blanks by each bolts.
Tell the foreman to come back when the chart is filled in. By the way, check him and the crew two or three times as he completes the chart.
Make sure he
RE: Bolting sequence
Regards,
Mike
RE: Bolting sequence
RE: Bolting sequence
does it matter if the flanges have stiffening webs (extending across the tighening flange) ? i'd've thought it did.
RE: Bolting sequence
-tg
RE: Bolting sequence
RE: Bolting sequence
RE: Bolting sequence
I would imagine that this would be no different than a 4, 8 or 24 bolt sequence. Number the bolts consecutively (clockwise) 1 through 280 starting with any bolt. Then tighten in this order: 1, (1+n/2), (1+n/4), (1+3n/4) where n is the number of bolt holes.
Start at bolt number one, locate the bolt 180° from bolt #1. (In your case it will be bolt number 141). Now go to bolt 71 and rotate to 211. Now to bolt 2, 142, 72, 212. 3, 143, 73, 213. etc.
RE: Bolting sequence
Regards,
Eric
RE: Bolting sequence
RE: Bolting sequence
Take the number of bolts and divide by 4.
Consider this your 'max' number.
Start at the 12 o'clock position and number this bolt '1'.
Going clockwise, mark each bolt as the prior bolt's #, plus 4.
If the number you're about to write is greater than your max number, mark it '3', and continue the pattern by adding 4 to get the next bolt number.
The next time you reach your max number, mark that bolt '2', continue again, and then when you max out again, that bolt is '4'.
Then you just tighten in sequence, in as many passes as called for. It's basically the same idea as above, but you're numbering the bolts via tightening sequence rather than position, and it's simple enough you can remember how to do it in the field.
Continue marking bolts until you reach #1.
RE: Bolting sequence
My apologies for not thinking of something useful for you in my earlier post:)
Regards,
Mike