Feature

Tubesheets, with the layout and the thickness together.

PlutoHX works out the tubesheet thickness and optimizes the tube layout, to ASME Part UHX and Division 2, Part 4.18.

The tubesheet layout of the reference exchanger: 554 tubes of 1 in outside diameter on a 1.25 in square pitch, in two passes of 277 tubes either side of the pass partition lane, with 8 tie rods, in a 40 in shell. — Open the drawing at full size

The rules

A tubesheet rule for each exchanger type.

UHX-12	Tubesheets of U-tube exchangers
UHX-13	Tubesheets of fixed tubesheet exchangers
UHX-14	Tubesheets of floating tubesheet exchangers, such as the reference AET
Division 2, Part 4.18	Tubesheets under the Division 2 rules, which Mandatory Appendix 46 opens to a Division 1 design

Optimization

Less material, with the strength kept.

PlutoHX optimizes the tubesheet thickness, the expansion joints, and the tubesheet-to-shell joints, so the design uses less material while it stays sound.

In Classic mode you set the mean metal temperatures, the pitch pattern and the Part UHX options, and any expansion joint, including bellows of the unreinforced, reinforced, or toroidal kind.

The reference bundle

The tubes of the reference exchanger.

The tube bundle of HX-123
Item	Value
Tubes	554
Tube outside diameter and wall	1 in, 0.134 in wall
Tube length	16 ft
Pitch and layout	1.25 in, 90 degree (square)
Tube passes	2, with 277 tubes a pass
Tie rods	8
Tube material	SA-179, seamless cold-drawn low-carbon steel

Tube-to-tubesheet joints

Expanded, seal welded, or strength welded.

A tube is held in the tubesheet in one of three ways: expanded into its hole; expanded and then seal welded; or strength welded. The joint follows ASME Part UHX and TEMA, the welds fall under UW-20 of Division 1, and ASME Section IX covers the welding procedures and the qualification of the welders.