Resilient Metallic Seals
`
`• Many Cross-Sectional Variations
`• Weld Integrity
`• High Quality
`
`Page 1 of 60
`
`

`

`Eaton’s Aerospace Group
`offers an extensive variety
`of standard catalogs featuring
`metal seals with numerous
`cross-sections, sizes and
`shapes adapted for various
`customer applications. We
`are able to offer short lead
`times on a number of prod-
`ucts, all made to order. Our
`sales, applications and design
`engineers are all available to
`work with you to solve your
`particular leakage problems
`in a timely, cost-effective
`manner, often using exist-
`ing designs adapted to your
`needs.
`
`As a preferred supplier,
`partnering supplier or long-
`term agreement holder with
`leading original equipment
`manufacturers worldwide,
`Eaton meets or exceeds
`today’s strict requirements
`for the supplier approval
`process, and commits to
`long-term, value-added rela-
`tionships with our custom-
`ers. Our talented employees
`are committed to supporting
`your needs in application
`assistance, design and value
`engineering, manufacturing,
`testing, quality assurance
`and delivery.
`
`do not print this page
`
`ii
`
`EATON Aerospace Group TF100-35D October 2013
`
`Page 2 of 60
`
`

`

`Table of Contents
`
`Introduction
`Introduction to Seals and Seal Types ..................................................2
`Typical Cavities ...................................................................................3
`Principles of Metallic Sealing ..............................................................3
`Selecting the Correct Seal for Your Application ...................................7
`
`C-Seals™
`C-Seal Sketch and Description ............................................................8
`Standard Part Number Selection ......................................................10
`Face Type, Internal Pressure C-Seal Tables .......................................12
`Radial C-Seals ...................................................................................15
`Face Type, External Pressure C-Seal Tables ......................................16
`Boss C-Seals .....................................................................................19
`
`E-Seals™
`E-Seal Sketch and Description ..........................................................20
`Standard Part Number Selection ......................................................22
`Standard Internal Pressure E-Seal Tables ..........................................24
`Standard External Pressure E-Seal Tables .........................................26
`High Flex Internal Pressure E-Seal Tables .........................................28
`High Flex External Pressure E-Seal Tables ........................................30
`Special 8 E-Seals ..............................................................................32
`
`U-Plex™ Seals
`U-Plex Seal Description ....................................................................42
`High-Flex U-Plex Seal Cross Section ................................................43
`Standard U-Plex Seal Cross Section Table ........................................44
`
`Microplex Seals
`Static Applications ............................................................................45
`
`More Seals
`Radial Type Seals ..............................................................................46
`More Seal Characteristics, Shapes, and Installation Options ...........47
`
`Appendix
`SI Conversion Factors, Glossary of Terms and Abbreviations ...........48
`Instructions for Filling in Drawing Forms ..........................................49
`
`EATON Aerospace Group TF100-35D October 2013
`
`1
`
`Page 3 of 60
`
`

`

`Introduction
`
`Truly static seals aim to provide
`a complete barrier to a potential
`leakage path; they are zero-
`leakage seals (down to 10-11 scc/
`sec.Helium).
`To achieve this, the seal must
`be resilient enough to conform
`to cavity irregularities and imper-
`fections, while remaining rigid
`enough to provide the required
`contact force needed to ensure
`a tight seal. This contact force is
`a function of the seal cross-sec-
`tion, as well as the compression
`of the seal between the mating
`cavity faces.
`Static seals, typically rigid, can
`be plated or coated with soft
`plating which, when the seal is
`installed, will plastically deform
`into and fill the surface imperfec-
`tions or asperities (Figure 1-1).
`Semi-static seals, on the other
`hand, are not designed or intend-
`ed to be zero-leakage seals. Their
`contact or compression force is
`typically an order of magnitude
`lower than the static seals. Table
`1-1 gives a typical comparison of
`load and leakage values for static
`and semi-static seals.
`The actual compression load is a
`function of the seal cross-section
`type (C-, E-, U- etc.), material
`type, heat treatment, material
`thickness, and the amount of
`compression or squeeze. These
`factors affect each type of cross-
`section differently; some factors
`have more effect on one section
`than another.
`
`Introduction to Seals
`and Seal Types
`A seal is a device that prevents
`the passage, flow or leakage
`of a gas or fluid. Seals can be
`divided into two major cate-
`gories:
`1. Static Seals. Sealing takes
`place between surfaces that
`have little or no movement
`relative to one another.
`2. Dynamic Seals. Sealing
`takes place between surfaces
`that have relative movement,
`i.e. the movement of a shaft
`relative to a housing.
`There are also seals that fall
`between these two categories
`and do not exactly fit into these
`basic definitions of static or
`dynamic seals. Some static
`seals are designed to accom-
`modate the limited movement
`of the surfaces being sealed, i.e.
`due to pressure and/or thermal
`cycling. These type of seals
`are sometimes referred to as
`resilient, quasi- or semi-static
`seals.
`
`Performance of Mechanical
`Seals
`There are many factors that
`interact and contribute to seal
`performance. Seal performance
`factors include seal geometry,
`contact force, cavity surface
`finish, sealing medium, pres-
`sure differentials and operating
`temperatures.
`
`
`FIGURE 1-1
`Purpose of Plating
`
`See Detail A
`
`Seal
`
`Plating Fills
`Surface Asperities
`
`Plating
`
`Cavity
`
`Seal
`
`Detail A
`
`2
`
`EATON Aerospace Group TF100-35D October 2013
`
`Static Seals
`As previously mentioned, static
`seals are used between surfaces
`which have little or no relative
`cycling (either radially or in the
`direction, or axis, of compres-
`sion) once assembled. These
`seals undergo a high degree of
`plastic deformation during instal-
`lation. Once used, static seals
`should be replaced because of
`the high plastic or permanent
`set (i.e. low elastic springback).
`Exceptions to this may occur
`when all of the following condi-
`tions are met:
`1. The measured seal axial
`height (free height) after op-
`eration still exceeds the cavity
`axial height by a minimum
`amount (please contact Eaton
`for guidelines regarding seal
`reusability).
`2. The same seal is to be re-
`placed into its original cavity.
`3. Upon reinstallation, the cavity
`axial height is less than or
`equal to its original height.
`By Eaton’s definitions, the C-Seal
`is the only static seal covered in
`this catalog.
`
`Semi-Static Seals
`All of the remaining seals in this
`catalog are semi-static (those
`seals designed to accommo-
`date cavity fluctuations due to
`thermal, mechanical, dynamic,
`i.e. vibrations, and/or pressure
`cycling).
`Semi-static seals, as opposed to
`static seals, are almost always
`reusable. Designed to operate
`primarily in the material’s elastic
`range, semi-static seals often
`exhibit full springback. A few ex-
`ceptions to this are listed below:
`1. Excessive compression.
`2. Inadequate or insufficient
`room for optimum seal cross-
`section or type, resulting in
`a stiff section (not flexible
`enough).
`3. Operating temperature
`extremes resulting in stress
`relaxation.
`Semi-static seals, in particular
`the E-Seal, U-Plex, and Micro-
`plex seals, exhibit compressive
`loads which are typically an order
`of magnitude less than those of
`a static seal. Therefore, platings
`are not used as a sealing aid
`since there is insufficient contact
`loading to plastically deform the
`platings typically used.
`
`TABLE 1-1
`Load and Leakage Values
`
`
`
`
`
`
`Cross-section
`
`
`
`
`Typical
`
`
`Load-to-compress
`
`Typical leakage rate
`
`(room temp, 100 psi ∆P)
`
`
`Static
`
`C-Seal
`
`
`
`250-350
`lbs./in.Circ.
`.005 SCFM/in.Ø
`to 10-11 scc/secHe††
`
`Semi-Static
`E-Seal, U-Plex,
`Wave-SealTM†, Twist-Flex®†
`25-150
`lbs./in.Circ.
`.01 SCFM/in.Ø
`
`† Load and leakage values may be higher or lower, respectively, for these sections, since they
`are radial-type seals.
`†† Range shown corresponds to unplated and plated seals, respectively; values dependent on
`surface finish and cross-section selected.
`
`Page 4 of 60
`
`

`

`Introduction
`
`FIGURE 1-2
`Standard Closed
`
`
`
`
`
`
`
`
`
`
`FIGURE 1-3
`Standard Open
`
`
`
`
`
`
`
`
`
`
`FIGURE 1-4
`Corner Cavity
`
`
`
`
`
`
`
`
`
`
`FIGURE 1-5
`Segmented Cavity
`
`FIGURE 1-6
`Cavity Dimensions
`
`Typical Cavities
`
`Cavity Type
`There are several cavity types
`that are considered standard.
`The cavity is a primary design
`constraint since it determines
`the physical envelope for the
`seal’s dimensions. The typical
`standard cavity types are briefly
`described below and depicted
`in Figures 1-2 through 1-5.
`1. Standard Closed Cavity.
`This type of cavity is charac-
`terized by a fully enclosed seal
`area. This type is sometimes
`referred to as a “U” type
`cavity. (Figure 1-2)
`2. Standard Open Cavity. This
`type of cavity is characterized
`by an open radial dimension.
`This type is referred to as an
`“L” type cavity. (Figure 1-3)
`3. Corner Cavity. This type of
`cavity is often seen in gas
`turbine engines. (Figure 1-4)
`4. Segmented. This type of
`cavity is often seen in gas
`turbine engines at the turbine
`vane, or nozzle sealing loca-
`tions. (Figure 1-5)
`
`Cavity Dimensions
`The following are important
`cavity design dimensions:
`• Minimum Outside Diameter
`(MIN.O.D.)
`• Maximum Inside Diameter
`(MAX. I.D.)
`• Corner Radii (R. MAX. TYP.)
`
`• Corner Edgebreak (CHAMF.)
`• Cavity Height (F)
`Figure 1-6 shows these dimen-
`sions on various cavities.
`
`Principles of Metallic Sealing
`
`I. Eaton’s Resilient Metallic
`Seals—When and Why Used?
`Eaton’s Metallic Seals are your
`optimum choice when sealing
`under any or all of the following
`conditions:
`A. High Temperatures to Cryo-
`genics—Material Selection
`B. High Pressure
`C. Long Life
`D. Cavity Fluctuations Due to
`Thermal and/or Pressure
`Cycling
`E. Need for Extended Shelf Life
`F. Sealing of Corrosive or Hard-
`to-Handle Gases or Liquids
`G. Need for Cleanliness; Zero
`Seal Outgassing
`
`A. High Temperatures
`to Cryogenics—Material
`Selection
`Metallic seals can be used to
`seal at temperatures outside the
`recommended operating range
`of elastomeric seals. Eaton can
`make a seal from almost any
`alloy that can be formed. In high-
`volume applications and when
`using newly developed alloys,
`the cost of the alloy is a factor to
`consider. Overwhelmingly, how-
`
`ever, strength (spring) properties
`are the primary technical consid-
`eration. The more severe the ap-
`plication, the more important it is
`to use strong, resilient materials.
`Iconel 718 is Eaton’s first choice
`of material when strength and
`resiliency are concerns. Inconel
`718 offers the best engineering
`properties for sealing within its
`operating temperature range.
`As for temperature limita-
`tions, seal materials offered in
`this catalog can be used from
`cryogenics to the elevated tem-
`peratures listed in Table 2, before
`the significant effects of stress
`relaxation and/or oxidation are
`encountered.
`These temperature recom-
`mendations correspond to the
`materials in their fully heat-treat-
`ed condition; this includes a full
`solution anneal and precipitation
`hardening. Please note static-
`type C-Seals are not recom-
`mended for applications above
`+1200°F (+649°C). At these
`temperatures, highly stressed
`material, such as that of a C-Seal
`when compressed, experiences
`a phenomenon known as Stress
`Accelerated Grain Boundary Oxi-
`dation Embrittlement (SAGBOE).
`This is a form of “…stress cor-
`rosion cracking, wherein stress
`and high temperature can result
`in a rapid diffusion of oxygen
`down grain boundaries (until
`the cross-section is sufficiently
`reduced and results in normal
`tensile failure). Sensitivity to this
`phenomenon depends on many
`
`C L
`
`C L
`
`C L
`
`Cavity Segments
`
`Cavity Height (F)
`
`Edgebreak (CHAMF.)
`
`8
`
`Maximum Inside Diameter (MAX. I.D.)
`Minimum Outside Diameter (MIN. O.D.)
`
`C L
`
`TABLE 2
`Temperature Limitations
`
`Seal Material
`
`
`Inconel X-750
`Inconel 718
`Waspaloy
`
`
`
`Seal Type
`
`
`
`Static
`
`All types
`Semi-Static
`
`Corner Radii
`(R MAX. TYP.)
`
`Max. Recommended
`Temperature†
`+1000°F (+538°C)
`+1200°F (+649°C)
`+1350°F (+732°C)
`
`† This maximum recommended temperature refers to the continuous operating temperature
`of the seal. Periodic rises from this temperature may be accommodated. Please consult Eaton
`details.
`
`EATON Aerospace Group TF100-35D October 2013
`
`3
`
`Page 5 of 60
`
`

`

`Introduction
`
`variables, including alloy chemis-
`try, processing history, and final
`heat treatment.”
`(This definition is courtesy of an Inco Alloys
`International Ins. Paper by D.F. Smith entitled
`Testing Sensitivity in Low CTE Superalloys
`dated 3/16/91.)
`For semi-static seal applications
`above +1300°F (+704°C), Eaton
`is researching and developing
`manufacturing methods for
`several new high-temperature
`superalloys. At this time, Eaton
`successfully utilizes alloys such
`as Haynes 188® in operating
`cycles with a maximum tem-
`perature of +1600°F (+871°C).
`Consult Eaton for any applica-
`tions with operating tempera-
`tures greater than +1350°F
`(+732°C).
`
`B. High Pressure
`Eaton’s seals are also designed
`for high-pressure use. C-Seals
`have operated successfully
`at pressures above 200,000
`psi, and E-Seals have survived
`pressure pulsations to 8,000 psi
`without fretting.
`Figure 1-7 shows one special
`feature of the C-Seal: once the
`seal is compressed, the diam-
`eter changes.
`This feature enables a clear-
`ance fit of the seal in the cavity
`at installation and a tighter fit
`between seal and cavity upon
`compression. This occurs as
`the seal outer diameter grows,
`or seal inner diameter shrinks,
`for an internally pressurized
`vs. externally pressurized seal,
`
`respectively. The benefit of the
`tighter fit is better hoop support
`for a highly pressurized seal.
`Although our semi-static seals
`do not exhibit similar behavior
`upon compression, it is impor-
`tant to note the I.D. and O.D.
`support is crucial to maintaining
`stability and avoiding burst and/
`or buckling of any cross-section
`when it is exposed to extreme
`pressures. This type of sup-
`port is commonly referred to
`as back support, as it is the
`“back” or “closed” portion of
`the seal which needs support to
`essentially limit and stop hoop
`stress from escalating. Figure 1-8
`shows how the seal cavity itself
`serves as a means of support-
`ing the seal.
`
`C. Long Life Required
`In addition to having an infinite
`shelf life, Eaton’s seals, when
`possible, are designed to have
`infinite operational life. Excep-
`tions to this would occur with
`seals operating under excessive-
`ly extreme conditions, especially
`related to temperature, wear
`and vibration. The manufacturing
`process itself involves a very
`rigorous test of the material;
`typical sealing applications are
`“mild” by comparison. This is
`especially true of welds. Used
`at +1300°F (+704°C) and above,
`Eaton E-Seals have been quali-
`fied through 1,100,000 pressure
`impulse cycles of 400 psi in
`pneumatic applications.
`
`D. Cavity Fluctuations Due
`to Thermal and/or Pressure
`Cycling
`Throughout this catalog the
`emphasis is on the ability of
`Eaton’s semi-static seals to
`accommodate a cavity’s axial
`and/or radial cycling. These types
`of cavity movements are shown
`in Figure 1-9.
`The material and cross-section
`selection affect the amount of
`spring or resiliency of the seal.
`Once compressed, a semi-static
`seal will spring back to a given
`height; sometimes equal to
`its original height, other times
`slightly lower. The key, however,
`is the amount of springback, or
`return, as depicted in Figure 1-10.
`
`E. Need for Extended
`Shelf Life
`Eaton’s seals are designed and
`packaged for infinite shelf life.
`Generally speaking, our platings
`also have very extended shelf
`lives, although some discolor-
`ation or plating oxidation may oc-
`cur after several years. Contact
`Eaton regarding any questions
`about the effect of platings on
`shelf life.
`
`F. Sealing of Corrosive
`or Hard-to-Handle Gases
`or Liquids
`Eaton’s seals are used to
`seal difficult media including
`+1200°F (+649°C) air, steam,
`various oils and lubricants,
`He, Fl, various Freons, HBr, HCl,
`
`HF, N2O SiCl4 and numerous
`other acids and bases.
`
`G. Need for Cleanliness;
`No Seal Outgassing
`Elastomeric seals typically out-
`gas water vapor, hydrocarbons,
`and other particulates which may
`contaminate the sealed system.
`Eaton’s metallic seals do not
`create such outgassing problems
`in your sealed system, and can
`often be retrofitted into your
`existing cavity.
`
`II. The PressureScience™
`Advantage
`A. Researched and developed
`products
`B. High quality
`C. Many cross-sectional
`variations to fit a variety
`of needs
`D. Weld tested during
`manufacture (weld integrity)
`
`A. Researched and
`Developed Products
`Eaton has been designing and
`manufacturing metallic seals
`for almost 50 years. We are the
`originators of the much copied C-
`and E-Seals and have the longest
`history of successful experience.
`Much of the equipment used in
`the manufacturing of these parts
`was designed and built by Eaton
`to meet the specialized needs
`of these products. Virtually all
`manufacturing is done in-house
`including tooling manufacturing,
`
`FIGURE 1-7
`Cross-Section Change Due to Compression
`
`FIGURE 1-8
`Back Support
`
`Back Support
`
`Free State
`
`Compressed State
`
`Installed
`
`C L
`
`Pressurized
`
`C L
`
`4
`
`EATON Aerospace Group TF100-35D October 2013
`
`Page 6 of 60
`
`

`

`Introduction
`
`welding, metal forming, heat
`treatment, electroplating and
`electropolishing. In addition,
`Eaton performs endurance,
`proof, burst and other qualifi-
`cation and development tests.
`
`B. High Quality
`The PressureScience quality
`system is capable of meeting
`the most stringent customer
`specifications. This is evidenced
`by the National Aerospace and
`Defense Contractors Accredita-
`tion Program (NADCAP) certifica-
`tions. NADCAP certification in
`Chemical Processing, Welding,
`Heat Treatment and Liquid
`Penetrant operations assures
`continued conformance to even
`the most stringent requirements.
`
`C. Weld Tested in
`Manufacture (Weld Integrity)
`During the entire forming pro-
`cess of Eaton’s seals, the weld
`area is exposed to stress and
`strain levels significantly higher
`than those it should ever experi-
`ence during normal operation.
`During the remainder of the
`forming process, the weld area
`is subjected to severe reverse
`angulations (semi-static sec-
`tions) and plastic deformation.
`Throughout this process, the
`weld maintains its integrity. Any
`deformation occurring during
`operation is negligible compared
`to that occurring during the form-
`ing process; in essence, forming
`is the most severe test.
`
`D. Many Cross-Sectional
`Variations to Fit your Needs
`In addition to the standard
`C- and E-Seal cross-sections
`which have earned Eaton an
`esteemed reputation and made
`us the world leader in static
`metallic seals, we continue
`to push the limits of design
`and manufacturability. This is
`well-demonstrated in other
`cross-sections featured in this
`catalog. Throughout this catalog
`are performance capabilities of
`some of our most popular types
`of cross-sections. If you are
`unable to find a suitable cross-
`section for your application’s
`needs, manufacture sections
`not mentioned in this catalog
`are also available. Many patents
`have evolved from our expertise
`in sealing challenging, non-
`standard applications. Concur-
`rent engineering philosophies
`emphasize establishing a team
`relationship with customers
`by understanding the custom-
`ers’ sealing requirements
`and design constraints, Eaton
`continues to provide innovative
`sealing solutions.
`
`FIGURE 1-9
`Axial and Radial Deflections
`
`FIGURE 1-10
`Springback
`
`2 x Springback
`
`Axial
`Deflection
`
`C L
`
`Radial Deflection
`
`Free State
`
`Compressed
`State
`
`Post-compressed
`State
`
`EATON Aerospace Group TF100-35D October 2013
`
`5
`
`Page 7 of 60
`
`

`

`Introduction
`
`Overview of Seals Covered in This Catalog
`
`TYPE OF SEAL
`
`Standard C-Seal
`
`
`and Boss-type C-Seal
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Standard E-Seal
`
`
`
`
`
`
`
`
`
`Special 8 E-Seals
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`U-Plex Seal
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`GENERAL COMMENTS AND BASIC FEATURES
`
`C-Seal
`• Good for “rigid” connections where little or no axial deflection occurs
`• Low leakage rates—can be enhanced by plating
`• Ultra high vacuum (10-10 Torr) to high pressure (200,000 psi) applications
`• Intended to deform plastically; little or no springback
`• Compression load in the range of 100 to 1000 pounds per circumferential
` inch of seal (PCI)
`• See page 9 for more information
`
`Boss-type C-Seal
`• Designed for AS5205 (AS54395) type fittings & A.N.D. 10050
` type bosses
`• Reusable, stays with fitting
`• Readily unscrews from the fitting
`• Load is not transmitted from the fitting to the boss through the seal
`• See page 19 for more information
`
`• Flexible, suitable for applications with cyclic axial deflection
`• Low leakage rates, but higher than C-Seal
`• Good springback and reusability characteristics
`• Compression in the range of 10 to 50 PCI
`• See page 20 for more information
`
`• Eight most popular designs
`• Can accommodate a wide range of cavity sizes and movements, beyond
` the Standard E-Seal
`• Existing sections, therefore shorter delivery times and at lower cost than
` custom designs
`• Build your cavity around your selection, based on operational and performance
` requirements (pages 33-41)
`• See page 32 for more information
`
`• Extremely flexible
`• Compression loads 2-3 times lower than the Standard E-Seal
`• Seal weld distorted flanges as much as 2.5 to 5 times the deformation
` accommodated by the Standard E-Seal
`• See page 42 for more information
`
`6
`
`EATON Aerospace Group TF100-35D October 2013
`
`Page 8 of 60
`
`

`

`Introduction
`
`TYPE OF SEAL
`
`
`
`Microplex Seal
`
`
`
`
`
`
`
`
`
`
`
`
`
`Radial Type Seals:
`Wave-Seal
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`GENERAL COMMENTS AND BASIC FEATURES
`
`• Flexible, suitable for applications with cyclic axial deflection
`• Low leakage, similar to E-seal
`• Good springback and reusability characteristics
`• Compression in the range of 5 to 50 pci
`• Designed for application where the full capabilities of the E-seal are not required
`• See page 45 for more information
`
`• Offers an interference fit on diameter
`• Can serve as a piston ring replacement
`• Can accommodate large axial movement by sliding
`• Used where no sealing face is available due to cavity geometric and/or
` load limitations
`• See page 46 for more information
`
`Selecting the Correct Seal
`for Your Application
`To determine the type of seal
`which is best suited for your
`application, first answer the
`following questions:
`Is the Application Static or
`Semi-Static?
`Static (C-) seals are intended
`for applications which:
`
`A. have no axial or radial
`movement
`B. require tight sealing
`C. can accommodate or require a
`substantial axial or radial load
`If this describes your applica-
`tion, go to the C-Seals section,
`pages 8-19.
`Semi-static seals are intended
`for applications which:
`
`A. have some axial and/or radial
`movement
`B. can accommodate some
`leakage
`C. require lower axial or radial
`loads
`If this describes your application,
`go to the Semi-Static section,
`pages 20-46.
`
`FIGURE 1-11
`Static Seal
`
`C L
`
`C L
`
`No Radial
`Movement
`
`No Radial
`Movement
`(Substantial
`Radial Load)
`
`No Axial Movement
`(Substantial Axial Load)
`
`No Axial Movement
`
`FIGURE 1-12
`Semi-Static Seals
`
`C L
`
`C L
`
`Axial Movement
`
`Axial Movement
`
`Radial
`Movement
`
`Radial
`Movement
`
`EATON Aerospace Group TF100-35D October 2013
`
`7
`
`Page 9 of 60
`
`

`

`C-Seals
`
`Free Height
`
`C-Seal Sketch and
`Description
`
`Eaton’s C-Seal Performance
`Capabilities:
`• Excellent for “rigid” connec-
`tions where minimal or no
`axial deflection occurs
`• Low Leakage rates (10-11 scc/
`sec of Helium)
`• Ultra high vacuum (10-10 Torr)
`to high pressure (200,000 psi)
`applications
`• Intended to deform plastically;
`little or no springback
`• Compression load in the
`range of 100 to 1000 PCI
`An improvement on the classic
`metal “O” ring, the C-Seal pro-
`vides a more flexible, lower load
`sealing solution which is also
`pressure energized. Available in
`three basic orientations (Internal
`Pressure Face Type, External
`Pressure Face Type, and Radial
`Type), the C-Seal offers a simple,
`inexpensive, and reliable design.
`
`Typical Applications and
`Locations
`• Water Injection Valve—seal-
`ing water at 1000 psi, +600°F
`(+315°C)
`• Cryogenic Fitting—sealing
`liquid nitrogen at 1500 psi
`with zero leakage
`• Fuel Injector Seal—sealing
`fuel at 350 psi, +1000°F
`
`
`
`(+538°C), with high exposure
`to oxygen
`• Cryogenic conditions under
`vacuum, sealing helium
`• Toxic or corrosive gases used
`in laser processing
`• Toxic or corrosive gases used
`in processing and process
`equipment industries
`• Infrared sensing instruments
`
`High-Pressure Capability
`To transition from an “O” ring to
`a “C” shape, the hoop restraint
`of the seal was greatly reduced.
`The C-Seal was designed to fit
`the cavity loosely at installa-
`tion, but tightly at assembly, or
`“bolt-up.”
`Once the closed side of the seal
`is butted up against the rigid
`surface of the cavity, the hoop
`stress is essentially fixed, thus
`allowing an increase in pressure
`without an increase in hoop
`stress through the cross-section.
`This feature has permitted
`successful operation of Eaton’s
`C-Seals above 200,000 psi.
`Although originally designed
`for high pressures, C-Seals also
`work extremely well in lower
`pressure situations because of
`their springback and compres-
`sive strength characteristics.
`Additionally, in vacuum environ-
`ments, the seals tolerate bake-
`out, and soft platings enable
`consistent sealing to 10-11 scc/sec
`Helium.
`
`Very Tight Leakage Control
`Another feature of the C-Seal,
`as with all Eaton seals, is the
`curved or radiused sealing
`surface.
`This radiused sealing surface
`ensures a circumferential line
`contact which translates into
`high unit load on the plating, and
`thus an effective deformation of
`the plating into surface irregu-
`larities. This line contact offers
`the best balance with a maxi-
`mum unit load on the plating
`with minimum total load on the
`flanges. Since sealing does not
`take place on a sharp edge, the
`problem inherent in plating sharp
`edges is completely eliminated.
`Thus, the contact faces are not
`coined or damaged in use.
`
`Deflection Capability
`C-Seals are designed to deform
`plastically upon a small amount
`of compression or squeeze.
`The recommended squeeze on
`any given C-Seal cross-section
`is 20%. Once compressed, the
`C-Seal will deform plastically.
`However, it will exhibit some
`springback. Re-use depends on
`reinstallation conditions. C-Seals
`may be reusable in their original
`cavities, or in cavities that are
`very nearly the same depth as
`the original. This does not always
`apply to plated seals in rough
`(> 63 RMS) cavities. PLEASE
`CONSULT EATON FOR RE-USE
`REOMMENDATIONS.
`
`FIGURE 2-1
`Back Support
`
`Back Support
`
`FIGURE 2-2
`Curved Sealing Surface
`
`Radius
`
`Sealing Surface
`
`Installed
`
`C L
`
`Pressurized
`
`C L
`
`8
`
`EATON Aerospace Group TF100-35D October 2013
`
`Page 10 of 60
`
`

`

`C-Seals
`
`Typical load, deflection, or spring-
`back capabilities are shown in
`the Load vs. Deflection graph
`on page 11. It is not suggested,
`however, that the C-Seal be
`utilized in a cavity exhibiting this
`amount of continuous cavity
`cycling during operation. As a
`rule, a C-Seal will springback
`2% of its free height. Repeated
`reinstallations or continuous cav-
`ity fluctuations in excess of this
`amount could result in failure of
`the seal through cyclic fatigue
`and cracking.
`
`Standard C-Seal Part
`Number Selection
`The following pages support a
`simple part number selection
`process. Make your selection
`based on the following criteria:
`1. Seal Type and Orientation.
`Face type, internal or external
`pressure orientation. Radial
`type, seal either internal or
`external pressure, depending
`on installation orientation.
`2. Seal Axial Free Height.
`Choose a seal size based on
`cavity dimensions. The seal
`material thickness and heat
`treatment may be varied to at-
`tain different load and deflec-
`tion characteristics. Graphs
`and scaling factors are pro-
`vided to assist in the proper
`selection. Also, if a cavity has
`not yet been defined, a cross-
`section based on desired load
`and deflection characteristics
`can be selected first, then use
`the diameter tables to design
`the cavity.
`
`3. Material Thickness and Heat
`Treat. Cross-sections are of-
`fered in standard and thinner-
`than-standard thicknesses for
`those applications requiring
`reduced load. As for Heat
`Treatment options, we recom-
`mend full heat-treatment (so-
`lution anneal and precipitation
`hardening). However, NONE
`may be selected to minimize
`loadings. Scaling factors for
`Material Thickness and Heat
`Treat options are available on
`page 11.
`4. Material Type. The preferred
`material of choice for strength
`and load characteristics is
`Inconel 718.
`5. Plating. Select a plating
`based on maximum operat-
`ing temperature and leakage
`control requirements, as well
`as compatibility with media to
`be sealed. Details on accept-
`able temperature limitations
`and leakage comparisons by
`plating are provided.
`6. Diameter Dash Number.
`The size of a seal and cavity.
`Please note, we can also
`manufacture “in-between”
`sizes, and larger sizes not
`included in this catalog. Also,
`not all sizes referenced are
`kept in stock. Please consult
`Eaton to check availability or
`lead time by calling 301-937-
`4010.
`7. Catalog Code. Always desig-
`nated by a “C.”
`
`EATON Aerospace Group TF100-35D October 2013
`
`9
`
`Page 11 of 60
`
`

`

`C-Seals
`
`After selecting the part number, expedite your order by filling out a
`copy of the appropriate drawing form in the Appendix, and faxing to the
`number on the form. Instructions on filling out the drawing form can be
`found in the Appendix.
`
`6 1 4 A 9 1 – 0 0 3 6 – C
`
`CATALOG CODE
`Only option is –C.
`
`DIAMETER DASH NUMBERS
`See Tables on pages 12-18 for four-digit diameter designation code.
`
`PLATING
`
`
`
`
`
`Plating
`
`
`None
`
`Silver, per AMS 2411
`Gold, per MIL-G-45204
`Nickel, per AMS 2424
`
`Lead, per AMS 2414
`
`Tin, per MIL-T-10727
`
`Special Silver, per
`
`Eaton spec 0900
`
`
`MATERIAL TYPE
`
`
`Material
`9:
`Inconel 718
`
`
`
`Plating Thickness, in.
`
`Thick
`Thin
`
`
`—
`—
`
`.0015 - .0025
`.0005 - .0015
`.0007 - .0012
`.0003 - .0008
`.0015 - .003
`.0005 - .002
`.002 - .004
`
`.001 - .0025
`—
`
`—
`
`.0015 - .0025, Silver (per AMS 2410)
`PLUS .0003 - .0008, gold (per MIL-G-45204)
`
`
`P/N Code
`Thick
`Thin
`Ø – (only option)
`1-
`X-
`2-
`Y-
`N-
`5-
`6-
`P-
`—
`—
`
`Knoop
`Hardness
`(Reference Only)
`40-65
`40-75
`90-100
`15 or lower
`6-12
`
`F – (Only Option)
`
`39-45
`
`Remarks—operating temperature (T)
`+1000˚F<T ≤ +1200˚F† (+538°C<T ≤ +649°C)
`
`† Please consult Eaton for applications above +1200°F (+649°C).
`
`SEAL AXIAL FREE HEIGHT
`
`MATERIAL THICKNESS AND HEAT TREAT
`
`(Thickness applies to Ø dash numbers greater than 0007.
`For dash numbers 0007 and smaller at 1/16" and 3/32" free height, consult factory)
`P/N Code
`
`2
`3
`4
`5
`6
`Free Height
`1/16"
`3/32"
`1/8"
`3/16"
`1/4"
`Standard Thickness
`.010"
`.015"
`.015"
`.020"
`.025"
`Thinner than Standard .007"
`.010"
`.010"
`.015"
`.020"
`
`
`
`None
`A
`B
`
`Code
`
`
`
`
`Full
`R
`S
`
`SEAL TYPE AND ORIENTATION
`61: face type, internal pressure
`62: radial type
`63: face type, external pressure
`
`61
`
`C L
`
`C L
`
`62
`
`63
`
`C L
`
`10
`
`EATON Aerospace Group TF100-35D October 2013
`
`Page 12 of 60
`
`

`

`Force (pounds per inch Circumference)
`
`cumference)
`
`Force (pounds per inch Cir
`
`C-Seals
`
`Load (FTC0) vs. Deflection
`FH = Free Height
`
`Plating vs. Temperature Data
`
`Plating—Leakage vs. Deflec-
`tion Data
`
`125 RMS Surface Finish
`125 RMS