RE: ASME RF Flange Joint using Spiral Wound Gasket

A Few Additional Comments:

The CAESAR module was originally intended to provide a "rough" go-by, to help the user decide whether or not a flange pair needed to be relocated in a spool or if moments at an equipment or vessel connection should be reduced. Several methods were provided so the user could see that predictions varied wildly, but in general were conservative.

The "y" value is intended for "seating" of the gasket in the bolt-up condition, so that when the proper bolt load exists in the operating condition, the gasket will seal.

Sour service often involves additional low stress and material considerations. Expertise addressing your specific situation should be sought, and project requirements studied carefully.

Regards,
Tony

From: <a href="/group/PipingDesign/post?postID=Vaqiw0oJtUODpQf7D3Wau3sLUr7D5oloDhgOVmOZKq4MbMhtAvSD9LlonSgNlBm2WtouTVU52jApYapiL-EyScmqAIp_">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=Vaqiw0oJtUODpQf7D3Wau3sLUr7D5oloDhgOVmOZKq4MbMhtAvSD9LlonSgNlBm2WtouTVU52jApYapiL-EyScmqAIp_">PipingDesign@yahoogroups.com</a>] On Behalf Of <a href="/group/PipingDesign/post?postID=dNe8tttuMk3JBkozmuZYKVf2n45fTjMgKpKOv2r0nY0OCtZYN4NKpR7hiEYDBQRvccYfJOtFKWe0">sviswan@technip.com</a> Sent: Tuesday, November 13, 2007 1:06 AM To: <a href="/group/PipingDesign/post?postID=Vaqiw0oJtUODpQf7D3Wau3sLUr7D5oloDhgOVmOZKq4MbMhtAvSD9LlonSgNlBm2WtouTVU52jApYapiL-EyScmqAIp_">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] ASME RF Flange Joint using Spiral Wound Gasket

I am trying to use a spiral wound gasket of SS316 windings and CNAF filler
with outer centering ring for a class 150 CS pipe class.

The joint under went a check for leak tightness using the CAESAR II module
for a joint of NPS 6 ASME B16.5 Class 150 RF Flange.

The bolt is ASTM A320 Gr B7M, the line is a SOUR service one. The flange material is A105N.

The ASME values of y and m of 10000 psi and 3 respectively results in the
bolt load not being adequate for the sealing.

Is the 10000 psi the minimum required for the sealing spiral wound gasket?

I have gone through the technical article titled designcriteria.pdf on the
flexitallic website.

Can any one please suggest a recourse to this. Is the use of spiral wound
gasket advisable on the class 150 flange joint.

Sajit Viswan
Piping materials engineer
Technip Abu Dhabi

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[Non-text portions of this message have been removed] Received on Tue Nov 13 11:08:00 2007