Are washers required on pipe flanges?

Are washers required on pipe flanges?

Mating with other joint components Water pipe flanges should normally only be coupled to identical flanges using studs or bolts with washers on both sides of the joint and nuts.

How do you torque a flange bolt?

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.

Why is torque sequencing used on flanges?

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 do you know if a bolt is torqued properly?

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 flange fasteners?

As its name suggests, a flange bolt is a fastener that features a skirt extending outwards from the head in a 360 degrees angle.

How do you measure a flange nut?

Place the end of a measuring tape on one of the flat sides of the nut’s outer perimeter. Stretch the tape measure across the nut’s diameter to the flat-side directly across from the one your pulling from. If the nut is metric, count the number of lines on the tape measure to find the measurement.

How tight should flange bolts be?

Exactly – the point of the bolts is to hold the toilet in place, NOT to create the seal. The seal is created by the wax ring. One quarter turn too far on that bolt and you’ve ruined a multi hundred dollar toilet. If it doesn’t move when you sit on it, it’s tight enough!

How tight should exhaust flange bolts be?

Tighten the bottom nut of the rear cylinder head exhaust flange to 9-18 in-lbs (1-2 Nm). Tighten the top nut to 100-120 in-lbs (11.3-13.6 Nm).

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 difference between bolt tensioning and torquing?

Bolt torque and bolt tensioning are both legitimate ways to seal a joint. Bolt torquing exerts a rotational force on the fastener, while bolt tensioning involves stretching a fastener with what looks like a hydraulic load cell.

How can you tell if a bolt is tight?

Make sure you’ve tightened the bolts to snug-tight condition using an impact machine before checking the bolts with torque. Snug-tight refers to the condition where tightness is achieved with an impact wrench or by hand with a worker using an ordinary wrench.

How to calculate the torque of a flange bolt?

Torque bolts and nuts in a “CRISS-CROSS” sequence using a minimum of three torquing passes and the maximum bolt stress as defined. PASS 1: Torque to a maximum of 30% of the final torque value in accordance with the torque sequence. Check that gasket is getting compressed uniformly.

When to use hydraulic Torquing on a flange bolt?

To achieve the benefits of the pre-loading, the clamping force in the screw must be higher than the joint separation load. When the bolt loading requires a torque higher than 678 Nm (500 ft-lbs.) to be applied, hydraulic bolt torquing is recommended.

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 correct sequence of torque passes for a flange?

Flange Bolt Torque Sequence. After the three basic torque passes are completed, repeat torquing the nuts at least once using the final torque in a “CRISS-CROSS” manner until no further rotation of the nut is observed. For easy handling, bolt numbering shall be done clockwise around the flange with the following sequence.