Modification to flange face 1

[posture]

Hi

I have a question whether it is permissible to modify an RTJ flange so that it becomes a RF flange.

Our project engineer has a problem where a supplier has sent in 1 1/2" 316 stainless steel adapter RTJ flanges when the valves they are being put on are RF. It is a class 150 system but the flanges and valves in question are class 300.

Replacement adapter flanges are on 10 week leadtime so they do not want to send them back.

They have suggested that we fill approx. 2mm of the RTJ groove with weld, then machine the flange face back to the correct raised face depth for a 300 lb RF flange and machine on the required spiral finish. See attached. All minimum dimensions will be met as per ASME B16.5

Is this permissible under 31.3 or other codes? Has anyone on here done this or similar in the past? Any additional precautions that we should take?

Regards

Posture

 

[LittleInch]

Whose problem is this - yours or the supplier / vendor.

If you can't get 1 1/2" #300 RF flanges in less than 10 weeks you're not using the internet to its best ability. I would like to bet I could get them tomorrow and on a plane on Monday, but it would cost you 5 times as much as waiting 10 weeks, but still a fraction of the cost of the whole job. Up to you - only you know how much 10 weeks delay will impact on things.

I've never heard of anyone doing what you're suggesting, even in deepest darkest soviet times when they welded pipe into flanged valves....

Your attachment doesn't load - try it again, looks like youve attached tyour file reference and not the file itself.

I would tell your supplier he had better supply the right flanges by the end of the week or you're going to and back charge him for the priveledge and stop making up ways for you to end up taking responsibility for HIS problem...

Just my opinion.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[posture]

Hi

Regarding the root cause of the problem... I am unsure. The Project engineer just brought the problem to my desk for a solution. I'm sure the project guys have investigated other options and are experienced in managing vendors.

They aren't just standard 1 1/2" flanges. They are adapter flanges with a special connection on the back for instrument tubing I believe, hence the long lead time. If they were standard flanges I wouldn't have wasted my time posting here.

Sketch now attached. what is proposed is physically possible but whether it is sensible or permissible is an other question.

Posture

 

[donf]

Take a look at this link (page 30):

http://flexitallic.com/uploads/files/broSpiralWound.pdf

The picture shows two RTJ flanges, but the concept applies to one RTJ and one RF flange.

I've sucessfully used them for a similar reason.

You should contact a reputable gasket supplier or manufacturer to confirm this will work for your application.

donf

 

[racookpe1978]

Tomorrow will be Tuesday morning. The parts should arrive before noon, since you ordered them this morning, right?