3 way to Tension the Load

What is Tensioning?
Tensioning is the direct axial stretching of the bolt to attain preload. Inaccuracies created through friction square measure eliminated. Massive mechanical effort to form torque is replaced with straight forward hydraulic pressure. the same load can be applied by tensioning multiple studs at the same time.

Tensioning needs longer bolts, and a seats on the assembly around the nut. Tensioning will be done victimisation clastic Bolt Tensioners or Hydraulic buggy.

There are 3 way to Tension:-

1.Heat
2.Hydraulic Tensioners
3.Mechanical Tensioners

1. Tensioning with Heat:-

Gas Bolt Heater:-

Objective:-
Correctly setup a gas bolt heater
Properly adjust oxy-acetylene flame
Correctly adjust air flow
Safely operate a gas bolt heater


Design:-
Heating causes a bolt to grow in length
Relieves tension on bolt
Gas Bolt Heater is machined from solid Stainless Steel
A single bolt heater can be adapted to fit most bolt sizes by changing the heating tube diameter and length

Operation:-

Select a heating tube that is 1/8” smaller than the hole in the bolt and approximately 3” shorter than the depth of the hole

Install heating tube in bolt heater

Use stainless steel reducing bushing for smaller heating tubes

Use high temperature thread compound

Tighten hand tight

Connect air line to bolt heater

Air pressure should be between 50-100 PSI

Set oxygen pressure to 14 PSI

Set Acetylene pressure to 7 PSI

Use Victor #5-W gas welding tip

Always use check valves

Adjust flame to obtain a carburizing flame

Carburizing flame has an acetylene feather

Insert bolt heater into bolt

Purge bolt cavity with air

Turn air valve off

Insert welding tip into gas bolt heater

Gradually open air valve approximately 1/8 turn

Observe color of heating tube through vent holes in gas bolt heater

Maintain a cherry red color by adjusting air valve

More air is cooler

Less air is hotter

For proper operation a balance of pressure must be maintained between welding tip and heating chamber back pressure

Excess back pressure will result in welding tip back-fire 

If back-fire occurs, close acetylene valve, remove welding tip from bolt heater, purge bolt cavity with air, and restart heating process

PRO’S:

Minimum Muscle

CON’S:

Hot

Slow

Inaccurate

Hard on Studs

Must have hole

Rough on gaskets

2.  Hydraulic Tensioners 

Various type of Hydraulic Tensioners 

1.Top Connect

2.Side Connect

3.Hydraulic Nut

                     Top Connect                                  Side Connect                           Hydraulic Nut    

   

3.Mechanical Tensioner:-

-Multiple Work

-Takes Forever

-Tiny Load Points

-Cant check Results

SIONERS

HYDRAULIC

VARIOUS TYPE OF  HYDRAULIC TENSIONERS

Heater

Gas Bolt Heater