Nozzle on blind weld detail
Nozzle on blind weld detail
(OP)
Dear all,
Thanks in advance for your kind reply,
Our client's specification states for welding joint full penetration shall be considered.
So, problem is:
A) Can we carry out SET-ON instead of SET-IN(see attachment) for welding nozzle on blind flange?
B) In cyclic loading set on weld detail (see attachment)is applicable or not?
Regards,
Mohsen Maleki
Thanks in advance for your kind reply,
Our client's specification states for welding joint full penetration shall be considered.
So, problem is:
A) Can we carry out SET-ON instead of SET-IN(see attachment) for welding nozzle on blind flange?
B) In cyclic loading set on weld detail (see attachment)is applicable or not?
Regards,
Mohsen Maleki





RE: Nozzle on blind weld detail
The answer would depend on the design parameters (like pressure and temperature)& service (like lethal or non-lethal).
RE: Nozzle on blind weld detail
For more information,
Pressure: 22 barg
Temperature: 315 C
There is also cyclic loading.
Service: Non-lethal
Regards,
Mohsen
RE: Nozzle on blind weld detail
RE: Nozzle on blind weld detail
Client specs can restrict the use of set-on details. I am not sure either detail has an advantage for cyclic service. By "cyclic loading" do you mean cyclic external loads? Or cyclic pressure/temperature loadings?
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Nozzle on blind weld detail
Reply A): yes
Reply B): is applicable
Nozzles can be of the set on type, but welding can be difficult or create problems such as lamellar tearing.
Design of the juncture of the two parts is a major consideration in reducing discontinuity stresses. Fillet weld shall be machined to suitable radius.
Although it is not possible to eliminate all stress risers and concentrations, some design details to be avoided are as
follows;
1. Use integral construction
2. Avoid fillet welds for attachments to pressure boundary
3. Avoid reinforcing pads
4. Avoid threaded connections
5. Avoid partial penetration welds
6. Avoid stud bolt connections
7. Avoid leg supports
Is a good engineering practice to use set-on nozzle and reduce the amount of welding material.
Regards
r6155
RE: Nozzle on blind weld detail
Cyclic loading is eventuated from cyclic pressure and temperature.
Regards,
Mohsen
RE: Nozzle on blind weld detail
What is your opinion for external attachment such as trunnion, insulation support, ladder and platform clips and etc.
All of them are attached by fillet weld.
Regards,
Mohsen
RE: Nozzle on blind weld detail
Please, see Pressure Vessel Design Manual 4th edit, by D. Moss.
Regards
r6155
RE: Nozzle on blind weld detail
RE: Nozzle on blind weld detail
My opinion: instead of fillet weld use full penetration weld + fillet weld and ground smooth or contoured.
Try to reduce the number of attachments (internal and external)
Regards
r6155
RE: Nozzle on blind weld detail
Dhurjati Sen
mk3223
SnTMan
TGS4
Kindly, I appreciate for your reply.
Regards,
M.Maleki
RE: Nozzle on blind weld detail
It would likely help with the fatigue design as well since it will have less sharp corners compared to your sketches.