Technical Briefs

Assuring Tube-to-Tubesheet Joint Tightness and Strength

[+] Author and Article Information
Stanley Yokell

MGT Inc.
F201 The Academy,
970 Aurora Avenue,
Boulder, CO 80302-7299
e-mail: syokell@mgt-inc.com

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received June 27, 2011; final manuscript received October 25, 2011; published online October 18, 2012. Assoc. Editor: William J. Koves.

J. Pressure Vessel Technol 134(6), 064502 (Oct 18, 2012) (7 pages) doi:10.1115/1.4006123 History: Received June 27, 2011; Revised October 25, 2011

This paper describes preparing mockup tubesheet specimens for visual examination using a digital microscope to determine that tube-to-tubesheet joint welds are of the specified size and that expanded joints are satisfactory for the intended purpose. It discusses nondestructive examinations (NDE) of the tubesheets and tube joints intended to assure achieving sufficient tightness and strength to satisfy the uses to which the exchangers will be put. This paper refers to the ASME Boiler and Pressure Vessel Code (Code) paragraphs that apply to tube joint welds and expanded joints including shear load testing when the Code requires it [1]. The discussion also addresses the need for manufacturers to have qualified tube joining procedures and personnel qualified to use the qualified procedures. The work concludes with a summary of ways to assure tube joint tightness and strength.

Copyright © 2012 by ASME
Your Session has timed out. Please sign back in to continue.


The ASME Boiler and Pressure Vessel Code, The American Society of Mechanical Engineers, New York. The current edition of the Code is the 2011 edition. The Code is published at two-year intervals.
Standard for Power Plant Heat Exchangers, 4th ed., 2004, The Heat Exchange Institute, Cleveland, OH.
Standards of the Tubular Exchanger Manufacturers Association, 9th ed., 2007, The Tubular Exchanger Manufacturers Association, Tarrytown, NY.
Standards for Closed Feedwater Heaters, 8th ed., 2008, The Heat Exchange Institute, Cleveland, OH.
Directive 97/23/EC of the European Parliament.
Yokell, S., 2007, “Hybrid Expansion Revisited,” ASME J. Pressure Vessel Technol., 129, pp.482–487. [CrossRef]
Yokell, S., 2011, “Pressure Testing Feedwater Heaters and Power Plant Auxiliary Heat Exchangers,” ASME J. Pressure Vessel Technol., 133, 054502. [CrossRef]


Grahic Jump Location
Fig. 9

VHX digital microscope used to examine the specimens shown in Figs. 10–16

Grahic Jump Location
Fig. 13

6R and 7L Groove 2. Insignificant discontinuities. Grooves are trapezoidal.

Grahic Jump Location
Fig. 14

Tube 6L and 7R at 2 in. No discontinuities.

Grahic Jump Location
Fig. 15

Tube 6L and 7R at 5 in. No discontinuities over the expanded length.

Grahic Jump Location
Fig. 16

Tube 7R and 8L at 2 in. Tube 8L is not in intimate contact with the tubesheet and the expansion is unacceptable.

Grahic Jump Location
Fig. 1

Ultrasonic testing feedwater heater tubesheet after weldwire cladding and machining

Grahic Jump Location
Fig. 2

Liquid penetrant examining a feedwater heater tubesheet cladding after machining

Grahic Jump Location
Fig. 3

Gas leak bubble testing feedwater heater tube-to-tubesheet joints

Grahic Jump Location
Fig. 4

Typical layout of mockup tubesheet specimen for feedwater heater with two tube thicknesses

Grahic Jump Location
Fig. 5

Photograph of specimen A 0.035 wall tubes

Grahic Jump Location
Fig. 6

Photograph of specimen B 0.035 wall tubes

Grahic Jump Location
Fig. 7

Photograph of specimen A 0.049 wall tubes

Grahic Jump Location
Fig. 8

Photograph of specimen B 0.049 wall tubes

Grahic Jump Location
Fig. 10

Tube-to-tubesheet welds at 6L and 7R Leak paths 0.0364 in. and 0.0364 in. Unexpanded gaps behind weld roots 0.387 in. and 0.375 in.

Grahic Jump Location
Fig. 11

7R and 6l Groove 1. Discontinuities are insignificant. Grooves are trapezoidal.

Grahic Jump Location
Fig. 12

7R and 6L Land between grooves. No discontinuities.




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In