How do you sequence torque flange bolts?

How do you sequence torque flange bolts?

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.

How do you torque a flange?

Ensuring proper flange alignment….First to half torque and second to final torque.

1. Put the socket on the head of the wrench.
2. Turn the nut by hand until it catches the screw threading.
3. Turn the handle clockwise to tighten the nut.
4. Stop turning the wrench when it stops clicking or moving.

What is a torquing 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). The clamp load produced during tightening is higher than 75% of the fastener’s proof load.

How do I determine bolt torque for flange connections?

Summary. The greater of the two values-Wm1 or Wm2-will dictate the minimum required design bolt load. The minimum required bolt load divided by the number of bolts in the flange will determine the minimum f, or force, needed to use the torque equation.

What general sequence should be used when tightening a series of bolts or nuts?

When there is a requirement of tightening of a number of bolts and nuts in a series, to make the part component get set down evenly and avoid distortions, the fasteners must be tightened in a crisscross fashion. This ensures the even distribution of clamping force.

How do you tighten a flange nut?

1. First time around just snug the nuts with a hand wrench.
2. Second time around tighten the nuts firmly with the same wrench.
3. Third time around apply approximately 25% recommended torque.
4. Fourth time apply approximately 75% of recommended torque.
5. Fifth time around, apply 100% of recommended torque.

How is torque pattern determined?

Begin with the formula T = K x U x D x P, where T is the torque, K is a standard representing 1.33, U is the coefficient of friction, D is the diameter of the fasteners, and P is the necessary preload.

How is bolt torque required?

DETERMINING TORQUE The general equation for bolt load based on applied torque is T = KFiDb where K = torque coefficient. K is a function of the coefficients of friction and collar friction in the joint, and these are based on variables such as surface finish, coatings, and so on.

What is the proper way to torque a bolt?

Place the socket and torque wrench on the fastener and tighten the bolt, holding the torque wrench by the handle at the end of the wrench. Rotate the torque wrench slowly and smoothly, continuing through the arc until the wrench clicks. The click indicates that you have reached the desired torque.

When to use Torquing on a flange bolt?

When the bolt loading requires a torque higher than 678 Nm (500 ft-lbs.) to be applied, hydraulic bolt torquing is recommended.

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.

What should be used to tighten flange bolts?

The bolts shall be tightened by torque control, using the Anti-seize lubricant shall be used such as Molykote or equivalent, before installation. The specified method of bolt tightening is equally applicable to coated, galvanized and ungalvanized bolts.

Which is the best bolting pattern for torquing a gasket?

While the Star Pattern is the most common, it is certainly not the only — or necessarily the best — bolting pattern to apply when torquing a bolted flange assembly. In fact, there is no “silver bullet” bolt tightening sequence ideal for torquing every type of flange or gasket.