welding tube to tubesheet

[skrie85]

I want to welding tube to tubesheet. I have qualified GTAW before by using plate (not mock-up test). Can I welding tube to tubesheet by using qualification of GTAW?

[Karthik]

Hi, You follow as below. QW-202.6 Tube-to-Tubesheet Qualification. When the applicable Code Section requires the use of QW-193 for tube-to-tubesheet demonstration mockup qualification tests, QW-193.1 shall apply. If specific qualification test requirements are not specified by the applicable Code Section, tube-to-tubesheet welds shall be qualified with one of the following methods: (a) groove welds per the requirements of QW-202.2 and QW-202.4 (b) a demonstration mockup per the requirements of QW-193.1 (c) fillet welds per the requirements of QW-202.2(c) (for nonpressure retaining tube-to-tubesheet welds only) andas per ASME Sec.VIII,Div.1   UW-20 TUBE-TO-TUBESHEET WELDS UW-20.1 Scope. These rules provide a basis for establishing weld sizes and allowable joint loads for full strength and partial strength tube-to-tubesheet welds. UW-20.2 Definitions UW-20.2(a) Full Strength Weld. A full strength tubeto- tubesheet weld is one in which the design strength is equal to or greater than the axial tube strength, Ft. When the weld in a tube-to-tubesheet joint meets the requirements of UW-20.4, it is a full strength weld and the joint does not require qualification by shear load testing. Such a weld also provides tube joint leak tightness. UW-20.2(b) Partial Strength Weld. A partial strength weld is one in which the design strength is based on the mechanical and thermal axial tube loads (in either direction) that are determined from the actual design conditions. The maximum allowable axial load of this weld may be determined in accordance with UW-20.5, Appendix A, or UW-18(d). When the weld in a tube-to-tubesheet joint meets the requirements of UW-20.5 or UW-18(d), it is a partial strength weld and the joint does not require qualification by shear load testing. Such a weld also provides tube joint leak tightness. UW-20.2(c) Seal Weld. A tube-to-tubesheet seal weld is one used to supplement an expanded tube joint to ensure 131 leak tightness. Its size has not been determined based on axial tube loading. UW-20.3 Nomenclature. The symbols UHX-15 TUBE-TO-TUBESHEET WELDS Tube-to-tubesheet welds shall be in accordance with UW-20, as applicable. Tube-to-tubesheet welds not covered by UW-20 shall be in accordance with U-2(g). .Conclusion.   If your tube to tubesheet joint fall in UW20.4 and 20.5 you no need to qualify with shear load test and existing qualification shall be used.If it is of Fillet weld type,then you have to follow Appemdix-A,and need to qualify with shear load test.   Thanks & Regards,   (karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282 --- On Fri, 9/17/10, skrie85 <skr...@yahoo.com> wrote:

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[John Henning]

Assuming you are using ASME B&PV Code, then in general you may use a plate qualification as the tube-to-tubesheet weld is a partial penetration weld.  However if your customer or the design/fabrication Code requires qualification by mock-up testing then Section IX QW-193, QW-288, and QW-303.5 apply. 

 

Section VIII Division I and Section I do not require the use of mock-ups.

 

Note that some older customer specifications will require mock up testing or tube-to-tubesheet qualification in accordance with Section VIII, Division 2, Article F-3.  This portion of Sc VIII has been deleted and replaced by the Sc IX paragraphs cited above.

 

“QW-193 Tube-to-Tubesheet Tests

When the applicable Code Section requires the use of this paragraph for tube-to-tubesheet demonstration mockup qualification, QW-193.1 through QW-193.1.3 shall apply.”

 

John

 

From: material...@googlegroups.com [mailto:material...@googlegroups.com] On Behalf Of skrie85
Sent: Thursday, September 16, 2010 10:46 PM
To: material...@googlegroups.com
Subject: [MW:7052] welding tube to tubesheet

 

I want to welding tube to tubesheet. I have qualified GTAW before by using plate (not mock-up test). Can I welding tube to tubesheet by using qualification of GTAW?

 

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