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[MW:1578] Re: weld profile

Dear Mr Herman Pieper
thanks for your completely response.
can u guide me which T,K,Y joints in offshore jacket,must be grinded?
thanks adv


From: "pieper-qsi@kpnmail.nl" <pieper-qsi@kpnmail.nl>
To: Materials & Welding <materials-welding@googlegroups.com>
Sent: Friday, February 13, 2009 2:32:41 AM
Subject: [MW:1574] Re: weld profile


Dear Mr. Ali Asghari,



- Because of this toe grinding (if executed properly) you will get a
smoother transition from weld to base material and lower the stress
concentration at the weld transition area, This mostly is applied on
welds which will be dynamically loaded in practice.

- No such toe grinding is not detrimental for the welds properties,
the contrary is true: because of  this your welded structure will have
better fatigue resistance properties afterwards.

- Depth of such Burr toe grinding should be maximum 2 mm, the 0.05T
applies on materials with small wall thickness.

- The philosophy is to improve fatigue resistance, authorities like
Lloyd's Register or ABS calculate a 3 times longer fatigue life after
such burr grinding.

- the welds on which this procedure should be executed have to be
determined by your customer.

Because the conditions after Burr grinding depends on the
craftsmanship of the operator and this is sometimes a little bit
critical. These days you also may use technologies like Esonix® UIT
(Ultrasonic Impact Treatment) or PIT (Pneumatic Impact Treatment) as a
replacement of Burr Grinding in order to achieve the desired result.
During such treatment the transition area will be reshaped together
with introducing compressive stresses in the sub surface area.

These technologies are more independent from the operator and in
general easy to apply and to reproduce.


Best regards,


Herman Pieper

Job van der Havestraat 6
8384 DB, Wilhelminaoord
Tel: 0521-380083
Mobiel: 06-51691215




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