Spiral Wound Gasket Flanged Joint Tightness

I do not think that any standard permits filling of graphite grease on the spiral wound gaskets.

In your case at 80 bar pressure and probably low(ambient) temperature spiral wound gasket with outer ring will work good enough... i dont know if you have any leakage and you are talking about online boxup of the flanged joint

SB

what do you mean by in order to enhance its tightness?

Dear SB,

Thanks...but, is there a standard that restrict it?

Dear Mahesh,

During tightness test, done with Nitrojen at 88 bars sometimes we have to tighten the joints because of leaks. spiral wound gaskets "don't like" being re-tightened. So we use addition of graphite grease on the clean surfaces of the flanges. It helps, but, the customer's supervisor isd blaming us for wrong doing, so we are looking for a standard to help our position.

By the way, manufacturers of pressure regulators actually instruct to use grease at static joints for the enhancement of its tightness. I have not found any standard for pipeline joints that support or rejects that.

Thanks for your help,

Tarzan

dear tarzan

I have searched for standards but could not find any that talks of tightening procedure for the spiral wound gasket or anythings that permits use of graphite grease. sorry about that. Some one else may shed a light on this one.

Apart from this, at our natural gas line when we have any leakage and we intend to carry out an online box-up of the flange, we clamp the flanged joint after filling it with graphite. but again this is not in black and white and there is no standard to support it. By the way the pressure in our case is much less i.e 40 bar

SB

Tarzan,

I'm sorry for coming onto this post so late. Nevertheless, I hope that I can provide some food for thought:

With all due respect, if you have to resort to using graphite grease to seal your joints, you have other more serious underlying issues. Are you using a generic one-fits-all gasket spec? Or, are you truly analyzing each application and selecting the optimum gasket for that particular service? The purchasing and stores folks love standardization but this sometimes comes at the cost of joint integrity.

I would suggest that you review your plant's methods of flange analysis, your specs for flange preps, your bolting procedures and, very importantly, your Assembly QA requirements. Having all of the aforementioned properly in place and adhered to goes a long way in avoiding start-up leakage or in-production leakage. It can be a daunting and complex process to get everything established but, it's well worth it. Unless, of course, your leaks are merely nuisance leaks which have no serious impact to either production or safety. In the latter case, it's overkill.

Good luck out there.

Dear friends,

You were all of great help...

We have updated our jointing procedures and instructions for the site personnel.

We have also found a concession in ASME PCC 1 for using a grease filler but we don't do it anymore.

Thanks again,

Tarzan

Tarzan,

I'm happy to hear that you're moving ahead in the right direction. In this regard, your colleagues may find ASME PCC-1-2010 to be quite helpful as well. Here's a link to a recent article in Mechanical Engineering which pertains to this:

Solving the Puzzel of Bolted Joints - Mechanical Engineering, June 2011

As I had mentioned, it's an intensive and often daunting process to implement a new paradigm of joint integrity into an organization's SOPs particularly when dealing with a well-entrenched status quo (if it weren't, we wouldn't be needed) but, the end result is a safe, well-functioning operation - and happy, relieved neighbours on the other side of the fence ;-)

Good luck!

Thanks!!