GASKETS
Engineering Data/FAQs
"M" and "Y" Data
"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)/A1 P
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 Assembly Stress Recommendations
The minimum recommended assembly stress for Garlock compressed sheet, GYLON® and GRAPH-LOCK® products differ from "M" and "Y" values. "M" and "Y" do not take factors such as flange condition and blowout resistance into account. Garlock offers the following minimum assembly stresses as rules of thumb to use to calculate installation bolt torques:
| Operating Pressure psig (bar) |
Minimum Recommended Assembly Stress psi (N/mm2) |
||
| 1/32" (0.8mm) Thick |
1/16" (1.6mm) Thick |
1/8" (3.2mm) Thick |
|
| Up to 300 (21) | 2500 (17) | 3600 (25) | 4800 (33) |
| Up to 800 (55) | 4800 (33) | 5400 (37) | 6400 (44) |
| Up to 2000 (140) | 7400 (51) | 8400 (58) | 9400 (65) |
Maximum recommended compressive stress for all GRAPH-LOCK®, compressed fiber and GYLON® gaskets = 15,000 psi.
| Style | Thickness | “M” | “Y” |
| BLUE-GARD® 3000 | 1/16" | 4.2 | 3050 psi |
| 1/8" | 5.2 | 4400 psi | |
| BLUE-GARD® 3200/3400 | 1/16" | 3.5 | 2100 psi |
| 1/8" | 6.6 | 3000 psi | |
| BLUE-GARD® 3300 | 1/16" | 2.1 | 3050 psi |
| 1/8" | 4.0 | 3500 psi | |
| BLUE-GARD® 3700 | 1/16" | 3.5 | 2800 psi |
| 1/8" | 6.7 | 4200 psi | |
| CP-3900 | 1/16" | 1.5 | 1800 psi |
| 1/8" | 1.5 | 3600 psi | |
| IFG® 5500 | 1/16" | 6.6 | 2600 psi |
| 1/8" | 6.6 | 3300 psi | |
| IFG® 5507 | 1/16" | 3.5 | 2400 psi |
| 1/8" | 5.5 | 3900 psi | |
| ST-706 | 1/16" | 11.4 | 4800 psi |
| 1/8" | 22 | 6500 psi | |
| HTC-9800 | 1/16" | 3.5 | 2350 psi |
| 1/8" | 8.0 | 3200 psi | |
| HTC-9850 | 1/16" | 6.5 | 2550 psi |
| 1/8" | 8.0 | 2800 psi | |
| G-9900 | 1/16" | 4.5 | 4100 psi |
| 1/8" | 6.0 | 4100 psi | |
| GYLON® 3500 Fawn | 1/16" (1.6mm) | 5.0 | 2750 psi |
| 1/8" (3.2mm) | 5.0 | 3500 psi | |
| GYLON® 3504 Blue | 1/16" | 3.0 | 1650 psi |
| 1/8" | 2.5 | 3000 psi | |
| 3/16" | 2.5 | 3000 psi | |
| 1/4" | 2.5 | 3000 psi | |
| GYLON® 3510 Off-white | 1/16" | 2.0 | 2350 psi |
| 1/8" | 2.0 | 2500 psi | |
| GYLON® 3530 Black | 1/16" | 2.8 | 1650 psi |
| GYLON® 3540 Microcellular | 1/16" | 3.0 | 1700 psi |
| 1/8" | 3.0 | 2200 psi | |
| 3/16" | 2.0 | 2200 psi | |
| 1/4" | 2.0 | 2500 psi | |
| GYLON® 3545 Microcellular | 1/16" | 2.6 | 1500 psi |
| 1/8" | 2.0 | 2200 psi | |
| 3/16" | 2.0 | 2200 psi | |
| 1/4" | 7.0 | 3700 psi | |
| GYLON® 3565 ENVELON® | 1/16" | 2.8 | 1400 psi |
| 1/8" | 3.7 | 2300 psi | |
| 3/16" | 5.5 | 2800 psi | |
| 1/4" | 6.0 | 2800 psi | |
| GYLON® HP 3560 | 1/16" | 5.0 | 3500 psi |
| 1/8" | 5.0 | 4000 psi | |
| GYLON® HP 3561 | 1/16" | 5.0 | 3500 psi |
| 1/8" | 5.0 | 4000 psi | |
| GRAPH-LOCK® 3123 (homogeneous) |
1/16" | 2.0 | 2500 psi |
| 1/8" | 2.0 | 2500 psi | |
| GRAPH-LOCK® 3124 (wire inserted) |
1/16" | 2.0 | 2500 psi |
| 1/8" | 2.0 | 2500 psi | |
| GRAPH-LOCK® 3125-SS (stainless foil inserted) |
1/16" | 6.5 | 3300 psi |
| 1/8" | 11.8 | 5900 psi | |
| GRAPH-LOCK® 3125-TC (tang core) |
1/16" | 2.6 | 2500 psi |
| 1/8" | 6.0 | 3000 psi |
The above factors were developed with procedures from ASTM F-586 at
leak rates of less than 1 cc/min. with nitrogen gas as the test medium. They do
not reflect the compressive stress required to survive pressure spike (blowout)
conditions. See "Gasket Assembly Stress Recommendations."
Warning:
Properties applications 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.
This performance data 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.