The Lamons CMG family of products are considered the standard in respect to corrugated metal gasket technology; an excellent choice for 150 and 300 class ASME flanges where available bolt loading is minimal. The substrate geometry promotes recovery and resilience through thermal cycles and extended service life. CMGs can be direct replacements for spiral wound gaskets and can eliminate inward buckling issues while creating a seal at moderate flange stresses. Available in a wide range of substrate alloys and covering layer options, CMG style flange gaskets can be utilized to solve many common flange problems. CMG substrate geometries are engineered to achieve maximum recovery characteristics. A specific pitch, core thickness and wall angle is engineered to maximize the seal’s ability to overcome relaxation through joint relaxation, pressure and thermal cycles.
CMG – Lamons Corrugated Metal Graphite (CMG)
A high performance gasket for standard flange or heat exchanger applications. The CMG molds in place by filling in irregularities of the spaces creating a superior seal. It maintains the seal even in harsh environments including hydrocarbons and steam applications. The gasket is ideal where low bolt load are present or where high gasket stresses are available. The thin profile is beneficial in areas where flange separation is limited. The heavy 22 gauge core and 1/8” pitch frequency results in superior recovery and crush resistance in the most demanding applications.
CMG-EX - Lamons CMG-EX
A premium variation of Lamons original CMG gasket design. The CMG-EX was designed specifically for heat exchanger applications and provides premium performance in cyclic applications and where a high level of radial shear is present. The differential movement between flanges on a cyclical application will cause tremendous relaxation on traditional heat exchanger jacketed gaskets. This problem is addressed by the design of the CMG-EX gasket as it maintains a superior seal through operation and upon retightening.
CMGT – The Lamons CMGT
Maintains the same distinctive performance of other corrugated metal designs but provides an additional level of chemical resistance by utilizing a PTFE inner ring. Premium flexible graphite covering layers are used over a corrugated substrate with a PTFE facing covering the inner perimeter of the gasket. This configuration allows the user to maintain a “fire safe” design and have the benefits of additional chemical resistance or graphite contamination in their process.
CMG-PTFE – The Lamons CMG-PTFE
Based upon the same design as the CMG but provides the use of expanded PTFE covering layers. This design is commonly used in FRP or plastic piping where low available load are critical. Premium chemical resistance is realized by the pure PTFE facings and a variety of metallurgical substrates than can be used to match the piping system. The same proprietary substrate geometry is utilized to optimize recovery and resilience.
Offers rebound and a recovery characteristic where movement between the flanges is a concern, and oxidation of the graphite facing is a potential at elevated temperatures. Lamons HTG (high temperature gasket) is configured such that the sealing benefit of graphite is included, and is protected with oxidation-resistant barriers of mica material.
Metallic gaskets can come in different styles like; double jacket, single jacket, or solid metal. Soft compressible filler material can be flexible graphite, PTFE, or non-asbestos compressed sheet type. The design of a metal jacketed gasket also may require different shapes and the styles mentioned above can be made to a variety. Lamons jacketed gaskets are normally manufactured with a high temperature filler. The standard filler is normally sufficient for applications up to 900º F. Other soft fillers are available for higher temperatures or special applications. The choice of the metal used for the jacketed part of the gasket would depend upon the corrosive conditions being encountered.
Style 300 Double Jacketed Gasket
Double-jacketed gaskets are probably the most commonly used style of gaskets in heat exchanger applications. They are available in virtually any material that is commercially available in 26-gauge sheet. They are also extensively used in standard flanges where the service is not critical. Since most double-jacketed gaskets are custom made, there is virtually no limit to size, shape or configuration in which these gaskets can be made. In some cases, nubbins are provided on heat exchanger designs to provide an intermediate seal. This nubbin is normally 1/64" high by 1/8" wide. Experience has indicated, however, that there is little advantage to this particular design. The primary seal is still dependent on the inner lap of the gasket doing the brute work and the secondary seal, when applicable, would be provided by the outer lap.
Style 333 Double Jacketed Corrugated Gasket
The double-jacketed corrugated gasket is an improvement on a plain jacketed gasket in that the corrugations on the gasket will provide an additional labyrinth seal. It also provides the advantage of reducing the contact area of the gasket, enhancing its compressive characteristics. A double-jacketed corrugated gasket still relies on the primary seal on the inner lap.
Style 310 Plain Flat Metal Gasket
Flat metal gaskets are best suited for applications such as valve bonnets, ammonia fittings, heat exchangers, hydraulic presses and tongue-and-groove joints. They can be used when compressibility is not required to compensate for flange surface finish, warpage or misalignment and where sufficient clamping force is available to seat the particular metal selected. They must be sealed by the flow of the gasket metal into the imperfections on the gasket seating surfaces of the flange. This requires heavy compressive forces. The hardness of gasket metal must be less than the hardness of the flanges to prevent damage to the gasket seating surface of the flange.
Style 340 Double Jacketed Corrugated Gasket With A Corrugated Metal Filler
At temperatures in excess of the range of 900° F to 1000° F where the standard soft filler is normally not recommended, a double-jacketed corrugated metal gasket with a corrugated metal filler can be beneficial. This construction has the advantages of the double-jacketed corrugated metal gasket and, in addition, since the filler is normally the same material as the gasket itself, the upper temperature limit would be determined by the metal being used. This type of gasket, depending upon metal selected, is designed to be a heat exchanger gasket for high pressure, high temperature applications.
Style 341 Double Jacketed Corrugated Gasket With A Corrugated Metal Filler
Style 341 is the same general configuration as the Style 340, specifically using a 1/32” thick corrugated metal filler. In addition, 0.015” thick flexible graphite will be applied to both top/bottom.
French Type Gasket
French type gaskets are available in a one-piece jacketed construction for narrow radial widths not exceeding 1/4" and in two- and three-piece constructions for wider applications. This type of gasket can also be used with the jacket on the external edge of the gasket when the application requires the outer edge of the gasket to be exposed to fluid pressure. The most widely used French type gaskets are fabricated using copper sheath. The double-jacketed construction is preferred over the French or single-jacketed construction, where practical, since it provides a totally sheathed gasket without exposed soft filler.
Style 350 Single Jacketed Gasket
The majority of applications for single-jacketed gaskets are normally 1/4" or less in radial width. This type of gasket is widely used in air tool applications and engine applications where space is limited, gasket seating surfaces are narrow and relatively low compressive forces are available for seating the gasket.
Style 382 Single-Jacketed Overlap
In the single-jacketed overlap construction the maximum flange width is approximately 1/4". this type of gasket is used when total enclosure of the soft filler material is required and when the flange width makes it impractical to use a double-jacketed gasket.
Style 375 Double-Jacketed Double-Shell Gasket
The double-jacketed, double-shelled gasket is similar to the double-jacketed gasket except that instead of using a shell and a washer, two shells are used in the fabrication of the gasket. It has the advantage of a double lap at both the I.D. and the O.D. of the gasket, adding greater stability to the gasket. The construction will withstand higher compressive loads. Double-shell gaskets are normally restricted to use in high pressure applications.
Style 395 Modified French Type
This particular type of gasket is normally used with very light flanges on duct work handling hot gases. Its construction consists of two French type shields welded together with a Cerafelt filler material on either side of the metal. Metal thickness is normally 26 gauge, rolled on the I.D. to act as a shield.
Style 320 Round Cross Section, Solid Metal Gasket
Round cross section solid metal gaskets are used on specifically designed flanges grooved or otherwise faced to accurately locate the gasket during assembly. These gaskets seal by a line contact which provides an initial high seating stress at low bolt loads. They are fabricated from wire formed to size and welded. The weld is then polished to the exact wire diameter.
Style 370 Corrugated Gasket Enhanced With A Strip Facing
The Style 370 includes cementing non-asbestos material strips or fiberglass cord to the corrugated faces – typically in the “valleys” or the use of a gasket compound.
Style 344 Profiled Gasket
Profiled type gaskets offer the desirable qualities of plain washer types and the added advantage of a reduced contact area provided by the V-shaped surface. It is used when a solid metal gasket is required because of pressure or temperature or because of the highly corrosive effect of the fluid to be contained and also when bolting is not sufficient to seat a flat washer.
Style 345 / 346 Profiled Gasket With A Metal Jacket
If flange conditions require a profile type gasket, but flange protection is required as well, the profile gasket may be supplied with either a single-jacketed or a double-jacketed shield. This will provide protection for the flanges and will minimize damage to the flange faces due to the profile surface.
Lamons high temperature gaskets represent the ultimate solution for industrial bolted joints that are exposed to extreme temperature. The HTG design combines the superior sealing performance of a premium oxidation inhibited grade flexible graphite with an exceptional oxidation barrier in mica/phyllosilicate. The combination of these two sealing materials allows the user to eliminate the effects of oxidation at extreme temperatures. Lamons HTG family of products are the most stable and impermeable gasket materials available for extreme temperatures. The overall effective rating of the HTG configuration can go to a MAX of 1500°F.
The labyrinth design of the spiral wound provides for enhanced oxidation protection. While Inconel X-750 is commonly selected as the winding metal, any alloy can be selected.
The Kammpro-HTG is recognized as a problem solver for heat exchangers, large vessels and equipment that experience high operating temperature. Kammpro-HTG represents the best technology available in regards to torque retention, load bearing characteristics and seal ability at elevated temperatures.
DEFENDER™ RG Sealing Gasket
All piping gaskets are designed to operate at their optimum on flange faces that are clean, free from scratches and indentations, flat, not distorted and have a gramophone surface finish between 125µ.ins to 250µ.ins. (3.2µ.M to 6.3µ.M).
Flange faces which have been subjected to crevice type corrosion attack at, or around, the inner portion of the flange sealing faces can occur over a period of time. In many field applications, the flange surface condition cannot be assessed until the bolted connection has been decommissioned and an inspection has determined the suitability of the flanges to accept the same type of gasket that was initially installed.
Depending on the extent of the flange face damage, the corroded surface may have extended onto the surface where gasket sealing element is seated and simply installing another gasket offers no guarantee the connection will remain tight and leak-free once the flange is commissioned back into service.
An assessment as to the suitability of the flange surfaces has to be made in real-time with several options available:
The Defender™ RG Sealing Gasket has been designed to offer a tight and high integrity sealing solution for use on flange faces that have been subjected to erosion, corrosion, chemical attack and abrasion without having to modify or re-work the flange faces.