Page 39 - Design Criteria.qxd

40 ® Welcome to the Next Generation of Sealing Technology
Minimum Seating Width
Gasket Design Sketches (See Table)
Gasket Material Factor Seating and
(m) Stress (Y) Notes Gasket Column
(psi) Group
Self-Energizing Types
O-rings, metallic, elastomer, and other gasket types 0 0
considered as self-sealing
Elastomers without fabric
Below 75A Shore Durometer 0.50 0
75A or higher Shore Durometer 1.00 200
(1a), (1b)
Elastomers with cotton fabric insertion 1.25 400 (1c), (1d),
(4), (5)
Vegetable fiber 1.75 1100
MRG 2.00 2,500
Flexpro 2.00 2,500
Flexicarb based products NR 2.00 2,500
SR 2.00 2,500
ST 2.00 2,500
Spiral wound metal, with filler 3.00 10,000 (1a), (1b)
Spiral wound Style LS, Flexicarb Filled/PTFE filledThermiculite filled 3.00 5,000
Corrugated metal Soft aluminum 2.50 2900
with filler Soft copper or brass 2.75 3700
or Iron or soft steel 3.00 4500 (1a), (1b)
Corrugated metal jacketed Monel or 4%-6% chrome 3.25 5500
with filler Stainless steels & Nickel based alloys 3.50 6500
Soft aluminum 2.75 3700 (1a), (1b),
Soft copper or brass 3.00 4500 (1c), (1d)
Corrugated metal Iron or soft steel 3.25 5500
Monel or 4%-6% chrome 3.50 6500
Stainless steels & Nickel based alloys 3.75 7600
Soft aluminum 3.25 5500 (1a)2, (1b)2,
Soft copper or brass 3.50 6500 (1c), (1d),
Flat metal jacketed, Iron or soft steel 3.75 7600 (2)
with filler Monel 3.50 8000
4%-6% chrome 3.75 9000
Stainless steels & Nickel based alloys 3.75 9000
Soft aluminum 3.25 5500 (1a), (1b),
Soft copper or brass 3.50 6500 (1c), (1d),
Grooved metal Iron or soft steel 3.75 7600 (2), (3)
Monel or 4%-6% chrome 3.75 9000
Stainless steels & Nickel based alloys 4.25 10100
Soft aluminum 4.00 8800 (1a), (1b),
Soft copper or brass 4.75 13000 (1c), (1d),
Solid flat metal Iron or soft steel 5.50 18000 (2), (3),
Monel or 4%-6% chrome 6.00 21800 (4), (5)
Stainless steels & Nickel based alloys 6.50 26000
Iron or soft steel 5.50 18000
Ring Joint Monel or 4%-6% chrome 6.00 21800 (6)
Stainless steels & Nickel based alloys 6.50 26000
ASME Boiler and Pressure Vessel Code Calculations
Gasket Materials and Contact Facings
Gasket factors (m) for Operating Conditions and Minimum Design Seating Stress (Y)
II
I
Notes:
This table gives a list of many commonly used gasket materials and contact facings with suggested design values of m and y that have generally proved satisfactory in actual service when using effective gasket seating width b given in
the table on the next page. The design values and other details given in this table are suggested only and are not mandatory.
The surface of a gasket having a lap should not be against the nubbin.