METAL/SPIRAL WOUND GASKETS
Engineering Data/FAQs
Gasket Factors "M" and "Y"
"M" and "Y" data are to be used for flange designs only as specified 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 flange 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 Design | Gasket Material | Gasket Factor "M" | Min. Design Seating Stress "Y" (psi) | |
| Spiral wound metal, non-asbestos filled |  |
Stainless steel or MONEL® | 3.00 | 10,000 |
| Garlock CONTROLLED DENSITY™ flexible graphite-filled spiral wound | |
Stainless steel or MONEL® | 3.00 | 7,500 |
| Garlock EDGE® | |
Stainless steel or MONEL® | 2.00 | 5,000 |
| Corrugated metal, non-asbestos or Corrugated metal-jacketed, non-asbestos filled |
 |
Soft aluminum Soft copper or brass Iron or soft steel MONEL® or 4%-6% chrome Stainless Steel |
2.50 2.75 3.00 3.25 3.50 |
2,900 3,700 4,500 5,500 6,500 |
| Corrugated metal |  |
Soft aluminum Soft copper or brass Iron or soft steel MONEL® or 4%-6% chrome Stainless Steel |
2.75 3.00 3.25 3.50 3.75 |
3,700 4,500 5,500 6,500 7,600 |
| Flat metal-jacketed, non-asbestos filled |  |
Soft aluminum Soft copper or brass Iron or soft steel MONEL® 4%-6% chrome Stainless Steel |
3.25 3.50 3.75 3.50 3.75 3.75 |
5,500 6,500 7,600 8,000 9,000 9,000 |
| Grooved metal |  |
Soft aluminum Soft copper or brass Iron or soft steel MONEL® or 4%-6% chrome Stainless Steel |
3.25 3.50 3.75 3.75 4.25 |
5,500 6,500 7,600 9,000 10,100 |
| Solid flat metal |  |
Soft aluminum Soft copper or brass Iron or soft steel MONEL® or 4%-6% chrome Stainless Steel |
4.00 4.75 5.50 6.00 6.50 |
8,800 13,000 18,000 21,800 26,000 |
| Ring joint |  |
Iron or soft steel MONEL® or 4%-6% chrome Stainless Steel |
5.50 6.00 6.50 |
18,000 21,800 26,000 |
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 previous formula. The design values
and other details given in this table are suggested only and are not mandatory.
MONEL® is a registered trademark of International Nickel.
WARNING:
Properties/application shown here are typical. Your specific application
should not be undertaken without independent study and evaluation for
suitability. For specific application recommendations consult Garlock.
Failure to select the proper sealing products could result in property
damage and/or serious personal injury.
Performance data published here has been developed from field testing, customer field reports and/or in-house testing.
While the utmost care has been used in compiling this information, we assume no responsibility for errors. Specifications subject to change without notice. This edition cancels all previous issues. Subject to change without notice.