FRENZELIT GASKET INSTALLATION PROCEDURE
For Style 7075 & 7085
| When the use of Compressed Asbestos was widespread and it was the "general service" sheet, everyone learned how to install it to achieve optimum performance. The foundation of most installation procedures for industrial standard flange gaskets was the B7 bolt. This bolt affords sufficient torque to put the necessary stress loads on the gaskets to achieve a leak free seal. Today, there are various gasket materials where there was one. Flexible Graphite, filled PTFE and the variety of Compressed Non-Asbestos materials cannot take this stress load without being damaged. In addition, each of these different materials require different stress loads to affect a seal. As a result, the proven installation practices that worked so well have been either altered or abandoned. Frenzelit's Compressed Graphite Gasket materials are engineered to seal at high stress loads. Our extensive successful field experience has proven that using B7 bolts and following this installation procedure provides long-life and leak free performance from Frenzelit's Compressed Graphite materials. You will get maximum performance from our gasket material when you use our Gasket Installation Procedure. |
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1. Clean and inspect the flanges. 2. Clean or replace your bolts with B7 bolts, nuts and washers. B7 bolts are highly recommended because they will pull straight or misaligned flanges tight enough together to properly compress the gaskets and effect a seal. Grade 2 bolts don't have the strength to withstand the torque required to achieve proper installation. A grade 2 head is bare and a B7 is black and has "B7" cast into its head. 3. Lubricate the B7 bolt's thread, nuts, washers and the underside of the head with a Graphite based compound. This type of lubricant offers the best torque co-efficient and gasket stress distribution. This is based on Ecole Polytechnique of Montreal's test results. Used gaskets coming out broken or in pieces indicates an insufficient stress load on the gasket. 4. Use flat washers. They are recommended to assure even distribution of the bolting force. 5. Use a torque wrench. The use of a torque wrench is highly recommended. This assures a longer life and leak free performance. Just as a good auto mechanic uses a torque wrench to install an automotive head gasket, a flange gasket should be torqued using our torque guide. |
6. The next step is to select the most desirable tool for the job. There are several types of torquing tools on the market. Power tools are time saving but should be used only on non-critical applications. Impact wrenches, even those with control devices, have too many variable dynamic forces to provide the proper bolt stress. With the B7 specification bolts, proper installation can be achieved with the use of click type torque wrench or direct dial reading torque wrench.
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| National Thread | Bolt Diameter in Inches | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 9/16 | 5/8 | 3/4 | 7/8 | 1 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | |
| Fine | 13 | 25 | 46 | 73 | 112 | 160 | 224 | 392 | 624 | 928 | 1348 | 1878 | 2531 | 3320 |
| Coarse | 11 | 23 | 42 | 65 | 99 | 143 | 198 | 351 | 566 | 848 | 1202 | 1696 | 2223 | 2951 |
Recommended torque is 80% of bolt's maximum yield shown in ft.-lbs.
OEM and MRO Non-Standard Gaskets
Please call our technicians with your non-standard gasket application data to ensure there is sufficient gasket stress to affect a seal. Torque formulas are available if you choose to do the necessary calculations yourself.
Why Use B7 Bolts?4" ring gasket for 150 lb. ANSI pipe flange with (8) 5/8" diameter bolts. Grade B7: National Coarse-Torque to 80% of yield=198 ft.-lb. Grade 2: National Coarse-Torque to 80% of Yield=98 ft.-lb. Resulting Gasket Stress: Using Grade B7 Bolts = 7170 Stress Using Grade 2 Bolts = 3550 Stress Results: 100% higher gasket stress using grade B7 bolts. |
Why Lubricate Bolts, Nuts and Washers?4" ring gasket for 150 lb. ANSI pipe flange with (8) 5/8" diameter Grade B7 bolts. Grade B7: National Coarse-Torque to 80% of Yield=198 ft.-lb. Existing bolts, unlubricated - Friction factor = 0.25 New bolts lubricated - Friction factor = .015 Resulting Gasket Stress @ 198 ft.-lb. Dry B7 Bolts = 5738 Stress Lubricated B7 Bolts = 9564 Stress Results: 67% higher gasket stress with lubricated bolts. |