Tube bending using tube bender


Why tube bending is needed?

Tube bending is especially when done with stainless steel tubing. Tube bending is to eliminate as many connections as possible. Connections invite leaks, and leaks are problematic. Long runs of instrument tubing made from standard 20-foot tube sections, however, require junctions be made somewhere, usually in the form of tube unions.

If an instrument tube must connect between a stationary object and a vibrating object, a straight
(square) run of the tube is actually not desirable, since it will not have much flexibility to absorb the
vibration. Instead, a vibration loop should be made in the tube, giving it the necessary elasticity to
tolerate the vibrational stresses.

Tube bender:

Tube Bender is a simple mechanical device used to bend a tube. The bending capacity of the bender is ranged according to the thickness of the tube to be bent. The tube to be bent is placed above the bender die and fixed to it using tube latch. The bender die is marked with angles that helps to decide how much a tube should be bend.

How to bend the tube using tube bender:

Before beginning the bending and cutting process, it is important that a complete design is identified that includes consideration, where appropriate, of the use of expansion loops, offsets, staggered joining and vertical gauging.

First, the tube is marked for bending. Minimum radius and minimum straight length extension should be calculated and marked in the tube.


R = Minimum Bend Radius

L = Minimum length of the straight tube required for the bottom of the tube in the accessory body. It is important not to bend too small a radius that will cause excessive ovality and may cause the pipe to weaken. The use of a suitable tube bender will avoid this problem.

  • Now mark the reference point, usually at the end of the tube. Then mark the bend mark from the reference mark where the tube should be bend.

  • After the marking is completed, fix the tube into the bender and lock the tube latch. Fix the tube straight and parallel to the handle.

  • Then align the zero on the roll support along the zero on the nameplate.

  • Adjust the bend mark in the tube with the L in the roll support.

  • Slowly push the short handle, bending the tube, until the 0-mark on the roll support meets the desired angle on the name plate.

  • There is a chance for the tube to spring back slightly. To avoid this release the handle bend once again.

Instrumentation tools used by technicians