Page 151 - GarlockFluidSealing2010

Gasket Factors "M" and "Y"
"M" and "Y" data are to be used for fange designs
only as specifed in the ASME Boiler and Pressure Vessel
Code Division 1, Section VIII, Appendix 2. They are not
meant to be used as gasket seating stress values in actual
service. Our bolt torque tables give that information and
should be used as such.
"M" - Maintenance Factor
A factor that provides the additional preload needed in
the fange fasteners to maintain the compressive load on a
gasket after internal pressure is applied to a joint.
M = (W - A2P) / A1P
Where: W = Total Fastener force (Ib. or N)
A2 = Inside area of gasket (in.2 or mm2)
P = Test pressure (psig or N/mm2 )
A1 = Gasket area (in.2 or mm2 )
"Y" - Minimum Design Seating Stress
The minimum compressive stress in pounds per
square inch (or bar) on the contact area of the gasket that
is required to provide a seal at an internal pressure of 2
psig (0.14 bar).
Y = W / A1
Gasket Min. Design
Gasket Design Gasket Material Factor Seating Stress
"M" "Y" (psi)
Spiral wound metal,
non-asbestos flled Stainless steel or MONEL® 3.00 10,000
Garlock CONTROLLED
DENSITY® fexible graphite- Stainless steel or MONEL® 3.00 7,500
flled spiral wound
Garlock EDGE ® Stainless steel or MONEL® 2.00 5,000
Stainless steel and 2.00 (1/16") 2,000 (1/16")
Garlock GRAPHONIC® fexible graphite 9.00 (1/8") 3,000 (1/8")
Liquid service: 2.00 900
Corrugated metal, Soft aluminum 2.50 2,900
non-asbestos Soft copper or brass 2.75 3,700
or Iron or soft steel 3.00 4,500
Corrugated metal-jacketed, MONEL® or 4%-6% chrome 3.25 5,500
non-asbestos flled Stainless steel 3.50 6,500
Soft aluminum 2.75 3,700
Soft copper or brass 3.00 4,500
Corrugated metal Iron or soft steel 3.25 5,500
MONEL® or 4%-6% chrome 3.50 6,500
Stainless steel 3.75 7,600
Soft aluminum 3.25 5,500
Soft copper or brass 3.50 6,500
Flat metal-jacketed, Iron or soft steel 3.75 7,600
non-asbestos flled MONEL® 3.50 8,000
4%-6% chrome 3.75 9,000
Stainless steel 3.75 9,000
Soft aluminum 3.25 5,500
Soft copper or brass 3.50 6,500
Grooved metal Iron or soft steel 3.75 7,600
MONEL® or 4%-6% chrome 3.75 9,000
Stainless steel 4.25 10,100
Soft aluminum 4.00 8,800
Soft copper or brass 4.75 13,000
Solid fat metal Iron or soft steel 5.50 18,000
MONEL® or 4%-6% chrome 6.00 21,800
Stainless steel 6.50 26,000
Iron or soft steel 5.50 18,000
Ring joint MONEL® or 4%-6% chrome 6.00 21,800
Stainless steel 6.50 26,000
MONEL® is a registered
trademark of International
Nickel.
This table lists many commonly used gasket materials and contact facings with suggested design values of "M" and "Y"
that generally have proven satisfactory in actual service when using effective gasket seating width B1 described in the
formula on page D-32. The design values and other details given in this table are suggested only and are not mandatory.
D-33