This paper presents the results of an experimental investigation conducted to evaluate the effect of initial tube-tubesheet diametral clearance on the integrity of roller-expanded tube-to-tubesheet joints in overenlarged tubesheet holes. The criteria of evaluating joint integrity include the pullout force and hydraulic tightness of the joints in which tubes were expanded to 5% wall reduction after metal to metal contact of the tube with the tubesheet hole. The levels of clearance investigated were selected to cover a range that exceeded by ten times that prescribed by the Tubular Exchangers Manufacturers Association (TEMA) standards (Standards for the Tubular Exchanger Manufacturers Association, 1988, 7th ed., TEMA, Tarrytown, NY). The pullout test results showed that, within the investigated range of clearance, the joint strength has not declined below the strength of joints with clearance levels within the TEMA range. In fact, the pullout force exhibited a slight linear increasing trend with the increase in initial clearance, which is attributed to the effect of tube strain hardening. The hydrotest results indicated that all joints within the investigated clearance levels were hydraulically tight when they were tested at 1.5 times the design pressure of the heat exchanger for a duration of $30min$. A relationship between rolling specific energy and initial joint clearance has been developed.

1.
Thomas C. Wilson, Inc.
Operating Instructions and Service Manual for Right Angle Tube Roller Model 909-1700, 2006, “
Guidelines for Tube Expansion
,” SM-156A, www.tcwilson.com/pdfs/service_manuals/SM-156_909-1700.pdfwww.tcwilson.com/pdfs/service_manuals/SM-156_909-1700.pdf.
2.
Standards for the Tubular Exchanger Manufacturers Association
, 1988, 7th ed., TEMA, Tarrytown, NY.
3.
Yokell
,
S.
, 1992, “
Expanded and Welded-and-Expanded Tube-to-Tube Sheet Joints
,”
ASME J. Pressure Vessel Technol.
0094-9930,
114
, pp.
157
165
.
4.
Shuaib
,
A. N.
,
Merah
,
N.
,
Khraisheh
,
M. K.
,
Allam
,
I.
, and
Al-Anizi
,
S.
, 2001, “
Experimental Investigation of Heat Exchanger Sheet Hole Enlargement
,”
ASME PVP Conference Proceedings
, Vol.
426
, pp.
229
233
.
5.
Fisher
,
F. F.
, and
Brown
,
G. J.
, 1954, “
Tube Expanding and Related Subjects
,”
Trans. ASME
0097-6822,
76
, pp.
563
575
.
6.
Merah
,
N.
,
Al-Zayer
,
A.
,
Shuaib
,
A. N.
, and
Arif
,
A.
, 2003, “
Finite Element Evaluation of Clearance Effect on Tube-To-Tubesheet Joint Strength
,”
Int. J. Pressure Vessels Piping
0308-0161,
80
(
12
), pp.
879
885
.
7.
Kalpakjian
,
S.
, and
Schmid
,
S. R.
, 2006,
Manufacturing Engineering and Technology
, 5th ed.,
Prentice-Hall
,
Upper Saddle River, NJ
, p.
698
.
8.
Williams
,
D. K.
, 2003, “
Predictions of Residual Stresses in the Mechanical Roll of HX Tubes in TEMA Grooves
,”
Design and Analysis Methods and Fitness for Service Evaluation for Pressure Vessels and Components
, PVP-Vol. No.
459
,
ASME
.
9.
Tube Cleaners and Expanders Airetool® Manual by Cooper Power Tools, 2005, SP-1100EN0 405-10M, http://www.coopertools.com/catalog/pdffiles/SP-1100_en.pdfhttp://www.coopertools.com/catalog/pdffiles/SP-1100_en.pdf.
10.
Mitra
,
A.
, 1998,
Fundamentals of Quality Control and Improvement
, 2nd ed.,
Prentice-Hall
,
Upper Saddle River, NJ
, Chap. 3, pp.
173
193
.
You do not currently have access to this content.