i'm looking for opinions on task-line gasket

[keller529]

a greybeard i work with is telling me to research the taskline gasket as he's never seen one fail by blowout. does anyone have any experience? we switched most of our plant over to cut eptfe sheet w/ fillers. this was before my time.

fyi taskline gasket is molded ptfe but has a perforated steel core embedded inside. individually hand-made as i understand, so i suppose they're rather expensive? what alternatives exist, just trying to glean on others' experience with it. thank you

 

[LittleInch]

Flange class?, contents, design pressure, temperature, flange material a have an impact on gasket choice, not to mention cost and whether the flange gets made and broken in a regular basis.

PTFE can creep a bit I think.

A link to the vendor would be good.

 

[keller529]

Flange class?, contents, design pressure, temperature, flange material a have an impact on gasket choice, not to mention cost and whether the flange gets made and broken in a regular basis.

PTFE can creep a bit I think.

A link to the vendor would be good.

150# stainless flanges at around 100 psi. used in pulp and paper processing

 

[A8yssUK]

I wish I read your thread here before replying to your other one and told you what you knew already... I regret nothing!

The metal core here really only aids blow out from over pressures and 100 psi is frankly nothing.. so a blow out is really only going to occur with loss of load so creep resistance is what you need more and your using ePTFEs's already so the metal core is basically doing very little. I've seen sheet PTFEs used without metal supports well past 100 bar in industry (but above 40 bar is generally recommended to use metal supports). Blow out testing (ASTM HoBT lab tests ) I have done myself on decent ePTFE and filled PTFE sheet gasket materials exceed 200 bar and the gasket stress loss needs to be over 90% before a major leak occurs.

If you are seeing blow outs then perhaps rather look into used bolt up procedures and see if you can increase the starting installation torques to utilize the gasket/flange/bolt materials better; generally a higher initial torque would then require the system to creep more to lose enough load to become an issue. Also a retorque after a heat up and cooldown procedure does wonders. [But don't hot torque!!]

Extra bonus points can come from disc spring washers / Bellevue washers which are awesome, but require some careful selection and utilisation.