Abstract： ASME B16.20:2017 pdf download.Metallic Gasketsfor Pipe Flanges. SW-2.6 Performance Testing For all corresponding sizes and pressure classes, finished gaskets (including windings as well as inner and outer rings) shall be capable of meeting...

ASME B16.20:2017 pdf download.Metallic Gasketsfor Pipe Flanges.

SW-2.6 Performance Testing

For all corresponding sizes and pressure classes, finished gaskets (including windings as well as inner and outer rings) shall be

capable of meeting a maximum permissible leakage rate of 0.0 137 mg/s.m (7.67E—10 lb/sec.in.). The circumferential length (meter (inch)I shall be calculated using the gasket outside diameter as shown in Tables SW-2.1-1 through SW-21-3. Testing shall be

conducted at ambient temperature using an external calibration gas with a known methane concentration and a test gas flow rate oil L/min.

(a) The test fixture shall have a surface lIrnsh per ASME B 16.5, be capable of shielding the gasket so as to direct any leakage to the monitoring probe, and be capable of applying a uniform load on the test gasket sealing element while internally pressurizing

the gasket with methane (minimum 97% purIty).

(b) Gasket stress due to the uniformly applied load shall be 35 MPa (5,000 psI) for Class 150,56 M Pa (8,000 psI) for Class 300 and Class 400. and 70 MPa (10,000 psI) for Class 600 and above.

(c) Test pressure shall be 20 bar (290 psi) for Cbss 150 and 40 bar (580 psI) for Class 300 and above.

(d) Test pressure shall be maintained bra minimum of 4 h, after which time three readings shall be taken at approximately 5-mm

intervals; the average of these three readings shall be compared to the maximum permissible leakage rate.

SW-3 MATERIALS

Metal wmndings and filler materials shall be in accordance with Table SW-3-1. The inner-ring material should match the winding

material unless the purchaser specifies otherwise. The centering ring may be carbon steel that is painted, metal plated, or

otherwise coated to inhibit atmospheric corrosion.

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