Parker O-Seal Division (CSS
Division)
The Parker Gask-O-Seal enjoys a leading role as a world class sealing
concept. Profoundly simple, yet enviably reliable, this engineered seal starts
with a metal or plastic plate (called a "retainer"). Strategically
positioned grooves are provided on one or both sides of this retainer. Finally,
a uniquely designed elastomeric sealing element is molded directly into these
grooves to produce an integrated sealing solution for virtually endless array of
challenging static face type applications.
Under pressure of assembly, the seal crown is displaced a pre-determined
amount (squeeze), into precisely developed void areas. This
"volume-to-void" relationship is essential to effective, long term,
sealing. With the proper squeeze and volume-to-void ratio designed into the seal
style itself, it is then left to the retainer to ensure a solid joint. This
joint will transmit the bulk of the load required to fasten the assembly
(alternate load path), while allowing for effective sealing against the faying
surfaces via the inherent memory, or resiliency, of the elastomer itself. It is
these four principals, volume-to-void ratio, squeeze, resilience, and alternate
load path that guides the design of the Gask-O-Seal as well as the design of two
other O-Seal sealing products, the Integral Seal and Fastener Seal.
Resilient Metal Seals are high performance, precision seals designed to
handle extreme temperatures as well as highly corrosive environments.
Resilient Metal Seals are composed of a metal retainer machined or formed out
of a hard alloy (x750 nickel alloy, 718 nickel alloy, stainless steel, Hasteloy,
etc.) and a second, softer metal (gold, silver, soft nickel, etc.) subsequently
plated on the retainer. It is this plating that creates the actual seal by
flowing into and sealing all the irregularities in the mating flanges. The base
metal is formed into a shape that will allow it to use its mechanical properties
to provide the resilience required to "flow" the plating metal. Cross
sectional shapes such as an "O" seal, a "C" or a spring
energized "C" seal, an "E" seal, a "V" seal, an
Omega seal, and many other special designs are used in resilient metal seals.
Each one of the above configurations has its own advantages. For more details
and a recommendation to best suit your system, please contact the O-Seal
division product engineering department.
Metal Gaskets are also available. They are essentially crush type sealing
devices available in a variety of corrugated and jacketed designs for extreme
temperatures and corrosive environments.
One other way to handle extreme temperatures is with Grafoil Gask-O-Seals and
Integral seals. Special engineered Grafoil seals bridge the gap between metal
and elastomeric seals. For these types of seals, formed-to-shape Grafoil
replaces the elastomer portion in Gask-O-Seals and Integrals seals. The Grafoil
seal can be wrapped in metal to further enhance the performance of the seal.
The Integral Seal is so named because it effectively integrates a stamped
metal or molded plastic retainer with a molded-in-place rubber sealing element
to create an extremely versatile sealing device. Not surprisingly, it has
occasionally been referred to as a "second-generation" Gask-O-Seal.
By its very composition, the Integral Seal lends itself to mass production
techniques and resultant low-cost benefits. Hence, it is quite cost effective in
meeting the competitive demands of high-volume sealing applications.
During the molding-in-place process, the carefully designed seal element is
either bonded to or mechanically interlocked with the edge of the metal, or
plastic, retainer. The retainer thickness can be reduced as low as .012" to
facilitate retrofitting in previously grooved flanged surfaces. For ungrooved
flanges, a slightly thicker retainer (.040" to .050") can be provided.
All Integral Seal designs adhere to the same time-proven fundamentals as our
Gask-O-Seal; namely controlled Squeeze, controlled Resilience and a
pre-determined Alternate Load Path.
Fastener Seals feature a rubber sealing element that is molded to the inside
perimeter of a metal washer. The inside perimeter of the washer has a complex
matrix of holes that allows the rubber to physically lock itself to the washer.
These seals may feature two piece construction using an O-ring within a metal
washer.
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