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# What is the correct order for tightening bolts on a flange?

## What is the correct order for tightening bolts on a flange?

Tightening sequence The first pass, lightly tighten the first bolt then move directly across or 180 degrees for the second bolt, then move1/4 turn around the circle or 90 degrees for the third bolt and directly across for the fourth. Continue this sequence until all bolts are tightened.

What is a bolt or nut tightening sequence?

Bolt tightening sequence, or torque sequence, is defined in the torque tightening procedure. Flange joints are torqued tight with the help of a torque wrench (manual or hydraulic). Torque bolts and nuts in a “CRISS-CROSS” sequence using a minimum of three torquing passes and the maximum bolt stress as defined.

How is flange bolt torque calculated?

Using a calibrated torque wrench (Manual or Hydraulic Torque Wrench), flange bolt torque can be measured during flange assembly….Applied Torque, T= (k∙f∙d)/12 in FPS Unit

1. T=Torque in ft-lb.
2. k=Dimensionless nut factor or tightening factor.
3. f=axial force in pounds.
4. d=Nominal bolt diameter in inches.

### How do you tighten a bolt?

Try to pick a wrench that is the closest size to the bolt and try different combinations of coins to get a snug fit. If the wrench is too small you can take a long nut and a bolt, screw the nut onto the bolt and tighten the bolt around the nut you want to tighten or loosen.

How do you know when torque is right?

Mark the tightened fastener and surrounding application. In the tightening direction, begin to slowly apply force to the tool until the first movement in the fastener is noted. The reading recorded is a good indication of the original torque applied to the joint. This is the best way to determine residual torque.

What is a bolt tightening sequence?

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. Flange joints are torque tight with the help of a torque wrench (Manual or hydronic wrench).

#### Why is the bolting sequence so important?

It is important to note that the bolting sequence is just one of the many important things to get right to ensure joint integrity. There are many other factors to consider such as gasket selection, bolt lubrication, bolt selection, and the condition of the flange sealing surface.

What is the correct bolt order for tightening the flange?

When tightening, always use the correct sequential bolt order for the flange. One final time – clockwise or counter clockwise sequentially around the flange. One final time – clockwise or counter clockwise sequentially around the flange.

What is torque sequence in torque tightening procedure?

Bolt tightening sequence or torque sequence is defined in torque tightening procedure. Most company has their Flange bolt torque tightening procedure that used during construction and operation of the plant.