PQR FOR TUBE-TUBESHEET JOINT

Question

PQR FOR TUBE-TUBESHEET JOINT

Eabrar (Mechanical)

(OP)

18 Aug 05 01:40

HI

Please clearly specify that ACCORDING TO asme ix, what are the essential requirements of a PQR to qualify the WPS of a tube-tubesheet joint?

I also need information regarding weld joint(thickness of tube and tubesheet) of test coupon to qualify WPS.

Awaiting your early reply.

Thanks

ijzer (Materials) · Answer 1 · 2005-08-18 02:20:30

ASME IX does not have a specific requirement for tube to tubesheet welding qualification.

weldtek (Materials) · Answer 2 · 2005-08-19 08:27:04

While Sec IX doesn't specifically address tube to tubesheet joints, there are rules to follow for qualifying weld procedures. These rules vary somewhat for different materials. What P# are you talking about and what are the thicknesses?

Eabrar (Mechanical) · Answer 3 · 2005-08-20 06:35:44

P.NO is 4. and tubesheet thickness is 180mm and tubes are of 2mm thickness...thanks

metengr (Materials) · Answer 4 · 2005-08-20 20:06:49

The reason that Section IX does not address tube to tubesheet welds specifically is because a tube to tubesheet weld falls under the category of either a fillet weld or groove weld (for partial penetration strength welds). If the tubesheet and tubes are designated as P-No4 material, a fillet/groove weld WPS for the P-No 4 tubesheet and tube thickness will work.

I would suggest that you have a small mock-up of several tube to tubesheet joints to assure proper weld technique in depositing the weld.

weldtek (Materials) · Answer 5 · 2005-08-22 09:16:05

Agree with Metengr. There are two ways to qualify a procedure to cover the extreme thickness differential you have. The first is to qualify a procedure using two material thicknesses, one representing the thicker material ( 1.5") and the second representing the thinner material ( .375") See QW 451. The second is to combime two PQR's. See QW 202.4. If you choose the second option, Metengr's suggestion is especially important.

ijzer (Materials) · Answer 6 · 2005-08-23 02:31:37

If you want a seperate qualification for Tube to Tubessheet welds , you could refere to ASME VIII div. 2 Article F-3

**guest0821** (visitor) · Answer 7 · 2005-09-20 22:04:22

It's correct that ASME VIII div. 2 Article F-3 lays out the guidelines of Tube# Tubesheet Qualification. However couple of important points are to be considered:
Tube Pitch(Square or Triangular) and ligament,Tube O.D and tube thickness.Smaller diameter tubes with lesser wall thickness requires more precise control of welding parameters.Also profile of the weld joint is important, e.g only fillet weld or groove & fillet weld , the tubes could be projected,flush or underflush etc. Some clients requires POR's on each/specific job requirements.Clients specifications are more specific for Tube to Tubesheet Qualifaction.

Hope it will help.

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PQR FOR TUBE-TUBESHEET JOINT