Full Description

This bulletin describes the experimental results of spiral wound gaskets tested on a pressure vessel with a 16" class 300 RFWN flange. The tests involve 24 gaskets for inward buckling without leakage, an additional 19 gaskets for leakage, and 4 gaskets for both buckling and leakage. The buckling tests are done under various combinations of bolt-up, external bending moment and pressure. The leakage tests are conducted at different gasket stress levels with and without external bending moment.

Spiral Wound Gasket inward buckling test: inward buckling of the inner windings of flexible graphite spiral would gaskets has been reported for class 1500 NPS 8", 10" and 12" and class 2500 NPS 8" and 10" with inner ring. To investigate the cause of buckling, PVRC Bolted Flanged Connections (BFC) Committee has initiated several projects, i.e., 98-03, 97-12G and 99-BFC-2. This bulletin, which is based on project 98-03, is used to supplement the studies from other PVRC projects.

Gasket leakage test: Extensive gasket leak tests both at room and elevated temperatures have been conducted under the sponsorship of the PVRC BFC Committee. These results were reported in various PVRC WRC Bulletins, BFC committee reports and technical conferences. The results of the ROom Temperature Gasket Tightness Test (ROTT) have been used to develop the PVRC gasket constants, which are the key parameters for the new ASME design rules for bolted flanged joints. However, many of these laboratory tests were conducted using scaled models with rigid plattens and under simulated conditions. Consequently, the experiment and the test results reported in this bulletin compliments those data obtained from a laboratory and give valuable insight of the joint leakage behavior of the interaction between studs, gasket and flange on a full-scale flange.

Flange joint subject to external bending moment: An extensive experimental and analytical program is being conducted under the Subcommittee on Flange Parameters Studies of the PVRC BFC Committee to investigate the effect of the external bending moment on the integrity and leakage of a bolted joint. The first in a series of WRC Bulletins covering this program was published in WRC Bulletin 450. Bulletin 450 deals with bending moment testing on NPS 4 class 150 weld-neck and lap joint flanges. This bulletin, which deals with a full size 16" flange joint provides valuable data for the overall program for bolted joints subjected to external bending moment.

Product Details

Published: 2001 Number of Pages: 66 File Size: 1 file , 4.7 MB