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# Why do you need a torque sequence for a flange?

## 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 determine the torque of a bolt?

The wrong way, asserts Archer, is to pick a number off a standard engineering table or to rely solely on the classic equation, T = KDP, in which T is the target tightening torque; K is the coefficient of friction, or nut factor; D is the nominal diameter of the bolt; and P is the desired tensile load on the bolt.

What’s the torque sequence for a Ford engine?

The torque sequence for all three Ford engines can be seen in the photo above. Again, the 289 and 302 are two-stepped (I do three steps) to between 65 and 72 lb-ft. The 351 develops more compression and horsepower, so it needs more torque on the head bolts.

What are the torque specs for SBC engines?

Intake manifold bolts and head studs/bolts have to be torqued in a certain pattern and to a certain torque spec in order for your engine to work properly. Intake manifold bolts on SBC engines should be torqued to 30 lb-ft in a two-step sequence.

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.

The wrong way, asserts Archer, is to pick a number off a standard engineering table or to rely solely on the classic equation, T = KDP, in which T is the target tightening torque; K is the coefficient of friction, or nut factor; D is the nominal diameter of the bolt; and P is the desired tensile load on the bolt.

The torque sequence for all three Ford engines can be seen in the photo above. Again, the 289 and 302 are two-stepped (I do three steps) to between 65 and 72 lb-ft. The 351 develops more compression and horsepower, so it needs more torque on the head bolts.

## Where can I find the latest torque specs?

Find the most up-to-date torque spec listings in electronic format. FelPro-Only.com is your convenient source for advanced sealing information. It’s the place to learn and share “tricks of the trade,” find proper diagnosis and installation instructions, and enjoy easy access to parts reference.

### Why is the bolt tightening sequence so important?

There are many different things that determine whether a new flange connection will be secure and leak-free. One of the most important is the bolt tightening sequence. To a new bolting apprentice, this may seem straightforward enough. But simply applying full torque to your first bolt and then moving onto the adjacent one is the wrong approach!

How is the tightening torque related to the clamping force?

Consequently the value of the clamping force is usually referred to as the tightening torque. As the clamping force is a linear function of both the turning angle of the screw and the pitch of the thread, there is a direct relation between the clamping force and the tightening torque within the elastic range of the screw elongation.

How many torquing passes in a criss-cross torque sequence?

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 Sequence: Torque to a maximum of 30% of the final torque value in accordance with the torque sequence.

## What kind of torque does an expedition have?

Control Arm-Upper To Axle Assembly 110 1320 149.14 Gen I – REAR Upper Suspension Arm to Axle Bolt Type: Bolt 100 1200 135.58 Gen I – FRONT Pivot Nuts/Bolts Type: Bolt 110 1320 149.14 Gen I – REAR Upper Suspension Arm to Frame Bolt Type: Bolt 24 288 32.54 Gen I – FRONT Differential Cover Bolts Type: Bolt 33 396 44.74

### Which is the correct sequence for tightening bolts?

Pass 1B – Tighten the next four bolts, placing each to the right of the already tightened bolts, to between 50% and 70% of the target ft-lbs. Pass 1C – Tighten the rest of the bolts in the pattern to 100% of your final torque.

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 Sequence: Torque to a maximum of 30% of the final torque value in accordance with the torque sequence.

How are LS head bolts stretched after torquing?

Read on for details to make sure you do it right. LS head bolts are torque-to-yield (TTY), meaning they cannot be reused a second time. A TTY bolt is stretched when fastened, typically with a specified degree of turn after torquing. This means the bolt will not go back to its original shape after being installed.

When to use hydraulic Torquing on a flange bolt?

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

The clamp load produced during tightening is higher than 75% of the fastener’s proof load. 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. Check conditions of flange faces for scratches, dirt and scale.

Ruth Doyle