What is tube to tubesheet welding?

Expansion of the tube into the tube hole grooves via hydraulic, explosive, or mechanical methods adds another step to the manufacturing process. Once the tube has been expanded, it is then welded around the outer diameter of the tube at the tubesheet.

How are tubes sealed into the tubesheet?

The tube-tubesheet joint is a true metal to metal seal obtained by expanding the tubes into the tubesheet. When the mechanical forces are removed, the tubes are subject to residual compressive stress and tubesheet has residual tensile stress, with the wall reduction being the amount of plastic strain in the tubes.

What is mock up test for tube to tubesheet joint?

Tube pullout testing is generally done by rolling a number of tubes at varying torque levels into a mockup of the actual tubesheet, and then pushing them out of the tubesheet while measuring the force required to remove the tubes.

What is tube expansion in heat exchanger?

Tube Expanding is the process of reducing a tube wall by compressing the outer diameter (OD) of the tube against a fixed container, such as rolling into tube sheets, drums, ferrules, or flanges. To assure a proper tube joint, the tube wall must be reduced by a predetermined percentage.

What is axial tube strength?

It simply specifies that the total axial load on the joint must be limited by the tube yield strength multiplied by the tube metal area reduced by a series of factors.

How do you calculate tube expansion percentage?

By subtracting “E” from the rolled diameter you determine the actual amount of expansion (tube wall reduction) on the inside diameter of your tube. This can be converted to a % of wall reduction by dividing the actual wall thickness (“B minus D”) . 130” into the amount of roll .

What is the difference between seal weld and strength Weld?

Strength Weld These welds are essentially the same as seal welds, except the tube hole in the tube sheet is grooved. This allows filler metal to be deposited and provide joint strength. If a tube is strength welded, mechanical expansion is not technically required, since the weld acts as the mechanical joint.

What is floating head in heat exchanger?

Floating head heat exchanger is one of the most used heat exchanger. As shown in the name of it, in this design, one end of the tubesheet is fixed to the shell, while the other one can “float” freely inside the shell.

What is a strength weld?

Strength Weld Strength welds are designed to carry longitudinal tube loads and provide leak tightness. These welds are essentially the same as seal welds, except the tube hole in the tube sheet is grooved. This allows filler metal to be deposited and provide joint strength.

What is mock-up test welding?

Mock-Up Testing ; For onstream welding, while there is fluid flowing inside the pipe or equipment The most important is the safety that is not going to burn through the weld and weld it must not happen Hydrogen cracking (HIC) according to the method used to prove that the simulated welding or the Mock-up test.