Nozzle Replacement

[mzwem]

Hi

A client wants to replace a 10" nozzle which is already in an insert plate with a new 10" Nozzle. According API 653 9.8, if you want to replace a nozzle you need to use an insert plate. The client doesn't want to remove the existing nozzle with the insert plate. Will it be allowed to remove only the nozzle and reinforcement plate to replace with a new nozzle and reinforcement plate? The material is group IV.

Thanks is advance

 

[IFRs]

Is the existing insert plate a thickened insert plate?
What is the shell thickness and grade?
What is the insert plate thickness and grade?
Was the original insert assembly PWHT?
Is the existing insert large enough to contain a repad and maintain weld spacing?

You may be able to just remove and replace the nozzle neck.
Then again, maybe not.

 

[mzwem]

I will get back to you once I have answers to all the questions.

So far I know this:

Is the existing insert plate a thickened insert plate? (Same thickness, from my understanding the insert was used because of a new bottom plate, i will confirm this)
What is the shell thickness and grade? 18 mm, S355
What is the insert plate thickness and grade? 18mm, S355
Was the original insert assembly PWHT? (I have queried this)
Is the existing insert large enough to contain a repad and maintain weld spacing? (Waiting for dimensions from the client)

 

[mzwem]

Ok, I got all the information from the client.

Is the existing insert plate a thickened insert plate? (Same thickness, 18 mm)
What is the shell thickness and grade? 18 mm, A36
What is the insert plate thickness and grade? 18mm, A36
Was the original insert assembly PWHT? (They don't have any records of this, tank was built in 1967)
Is the existing insert large enough to contain a repad and maintain weld spacing? (Yes)

My understanding is that because the A36 doesn't need heat treatment (Group 1) I can replace the Nozzle neck and reinforcement plate without removing insert plate. Am I right in saying that?

 

[IFRs]

I believe you are correct, you can pretty much do anything you want.
Not over 1" thick
Not 12" NPS or larger
Not over Group III
Not PWHT ( confirm - not a caustic or other product that would require stress relief )
Neck A106B seamless 1/2" thick ( Sch 80 / extra strong )
If you arc out the neck, be sure to cut the larger hole in the tank shell 11 1/4" Dia so you can get a full penetration weld there.
If you can't arc out the neck without making a hole in the repad larger than 10 7/8" diameter, plan on making the hole in the repad large enough to make a full-pen weld there also.

Hey - you heard it on the internet, make sure you can validate !!