Gasket type for epoxy lined vessel

[jtseng123]

Dear all,

For 150# flange rating CS vessel with internal epoxy lining for corrosion protection, per NACE SP0178-2007, Fig. A10 indicating lining is up to the bolt circle, meaning entire gasket seating surface shall be lined. Our supplier saying typical 304 SS spiral wound graphite filler gasket can damage the lining when opening the blind or mating flange. What will be the better gasket to use ?

 

[SnTMan]

I think I'd want flat face flanges with full face composition or perhaps rubber gaskets, assuming they are compatible with the process.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[r6155]

If lining is damaged it can be restored.

Regards
r6155

 

[jtseng123]

Unfortunately rubber gasket is not suitable due to content.

Our Korean vessel supplier saying that
"When blinds is assembled the nozzle with gasket, any damage of lining is not considered due to use the gasket.
However, The Damage of lining can occur when the gasket and blind is removed for maintenance.
We are concerned about the separation of the paint with gasket when gasket and blind is removed.
As you know, the gasket surface can not apply the blasting or power tool cleaning.
Therefore, it is difficult to repair the damage to the lining. even if it try to repair, It can cause problems in the sealing.".

The purpose of what they said is not to apply lining to face of flange. However, that does not meet the purpose of protection we need.

 

[r6155]

Try with stainless steel clad weld in contact surface.

Regards
r6155

 

[SnTMan]

jtseng123, the major gasket manufacturers have applications engineers on staff just for these kinds of questions. Give 'em a call...

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[JStephen]

If the owner has similar vessels in service, talking to their maintenance people might be informative, in regards to how damaged/undamaged, coated/uncoated those flange faces are, and whether it really matters.

 

[saplanti]

I think R6155 gave you a good advice with stainless steel cladding on the gasket contact surfaces of both side flanges. Then the epoxy lining is applied the non cladded surfaces. If this one is not viable for the job you may ask the manufacturer about their advice from the previous experience.

 

[jtseng123]

Only for small nozzle, such as 2", that can not be epoxy lined, we ask for WOL.

We have found sheet gasket, graphite bonded on 316 S.S. insert (Perforated Tang), may do the work.

Thanks for all the opinions.