What is the tightening sequence and torque?
Bolt tightening sequence or torque sequence is defined in the torque tightening procedure. Flange joints are torque tight with the help of a torque wrench (Manual or hydronic wrench). The clamp load produced during tightening is higher than 75% of the fastener’s proof load.
When torquing a flange Why is it important to use a proper tightening sequence?
Bolt / Stud Tightening Pattern One of the most difficult jobs is to produce the correct assembly pressure on the gasket, low enough to avoid damaging the gasket, but high enough to prevent a leak in the seal. It is vitally important to control accurately the amount of force applied to any particular flange arrangement.
What is the purpose of torque sequence?
With such a sequence, each bolt is tightened more than once so as to reduce the preload reduction caused by the tightening of the other bolts in the joint.
Why do you need a torque sequence for a flange?
Flange joints require proper tightening to avoid the leak of the fluid from the joint. Bolt tightening sequence or torque sequence is defined in the torque tightening procedure. Most company has their Flange bolt torque tightening procedure that used during construction and operation of the plant.
How to tighten cylinder head nuts for full torque?
One-third of full torque. RECOMMENDED SEQUENCE TIGHTENING CYLINDER HEAD NUTS ON THE MODEL A FORD O FRONT Beginning at cylinder head bolt #1 and moving in numerical sequence to bolt #2, then #3, etc., tighten nuts to final full torque of 50 foot-pounds by following the five steps listed below. a Step 2. Two-thirds of full torque. D Step 3.
Is there a way to measure the tightening torque?
The problem is that there is no practical way to measure the clamping force in normal production situations. Consequently the value of the clamping force is usually referred to as the tightening torque.
When to re-torque an API flange bolt?
Fourth time apply approximately 75% of recommended torque. Fifth time around, apply 100% of recommended torque. Continue tightening nuts all around until nuts do not move under 100% recommended torque. If possible, re-torque after 24 hours. M ost of any bolt preload loss occurs within 24.