Lamons CMG-EX gasket is a premium variation of Lamons original CMG gasket design. The CMG-EX was designed specifically for heat exchanger applications and offers the following benefits:
  • Highest level of sealability
  • Excellent flexibility in radial shearing forces, often found in heat exchangers
  • Maintains a seal upon retightening in heat exchanger applications
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Excellent Performance Results

Heat exchanger flanges faces heat and expand at different rates, causing radial shearing of the gasket. The CMG-EX has a higher resistance to radial sheer due to the combination of corrugation in the metallic core plus the thickness and density of the flexible graphite facing.*  Radial Shear Tightness Tests (RA.S.T.) were conducted at TTRL in Montreal, Canada and the CMG-EX gasket, shown below as CG5, exhibited LOW RELAXATION and ZERO LEAKAGE MEASURED! Refer to graphs below for actual test results.

LOW RELAXATION!**
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ZERO LEAKAGE MEASURED!**
Gaskets tested included:
 (DJ) Double Jacketed
(SW) Spiral Wound
(PG) Profiled gasket
(CG) Corrugated/flexible graphite faced designs
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Notes:

*Work Cited: “Failure of Heat Exchanger Gasket Due to Differential Radial Expansion of the Mating Flanges” by Dr. Warren Brown and David W. Reeves.

**Information taken from “Thermal Analysis of Bolted Joints” by Dr. Warren Brown, PVRC Bolted Joint Workshop Florida, February 2002.

Heat Exchanger Leaking?

Critical service heat exchanger leaks as well as nuisance leaks cost millions of dollars and maintenance time for typical refineries. Lamons has the answer. The CMG-EX gasket was tested in a major industry heat exchanger test (RA.S.T.) and performed best overall with low relaxation and ZERO leakage measured. This variation of our proven corrugated metal, flexible graphite faced product is now commercially available for use in heat exchangers. Our Application Engineers would be happy to assist you with technical information, or specific application assistance. Below are some technical guidelines for success with this product:

Guidelines for Lamons CMG-EX in Heat Exchangers
  1. Assure flange faces are not warped. Correct as needed.
  2. Do NOT use the CMG-EX with nubbin on flange face.
  3. Assure there is not a built in means of limiting gasket compression.
  4. Minimum gasket radial flange width of 1/2 inch. (Pass ribs may be more narrow)
  5. Insert alloy to be specified by user. Typically 304 or 316 stainless steel, “L” grade suggested.
  6. Verify the compatibility of the metal and flexible graphite with the process conditions. Above 850ºF? Contact Lamons Engineering Department.
  7. Use only NEW high strength bolts. B7 and B16 are most common.
  8. Use new hardened washers under new nuts.
  9. Lubricate nut facings and bolt threads.
  10. Engineering: Calculate loads to produce full area GASKET stress of 13,000 psi to 30,000 psi.
  11. Hold gasket in place with light dusting of compatible spray adhesive.
  12. Use torque wrench and high bolt loads.
  13. Success has been reported when the bolting has been retightened during initial heat-up to compensate for relaxation. Bolt retightening was performed at 300ºF in the RA.S.T. test, and was part of the successful results.