Types of Gaskets

Gaskets are used to create a static seal between two flanges faces, at various operating conditions, with varied pressure and temperature ratings. A gaskets fills the microscopic spaces and irregularities of the flange faces, and then it forms a seal that is designed to keep liquids and gases. Correct installation of damage-free gaskets and demage-free flange faces is a requirement for a leak-free flange connection.
If it would be technically possible, in order to manufacture flanges perfectly flat and smooth, and perfectly compatible with one another under all operating conditions, a gasket would not be necessary. But in normal practice it is not possible, because flange connections under any circumstances should be made. Small impurities and a small bit of dirt, is in practice not be avoided and therefore it is necessary to use a gasket.

Content:

Types of Gaskets

According to its material and structural characteristics, gaskets can be divided into non-metal gaskets, metal gaskets, metal-non-metal composite gaskets, and various types can be subdivided into several types.
Non-Metallic Gasket

  • Compressed Non-Asbestos Fibre Gasket (CNAF)
  • PTFE Gasket
  • Rubber Gasket

Metallic Gasket

Metal-non-metal Composite Gaskets

Spiral wound gasket

Spiral wound gasket, type CG.The first spiral wound gasket was developed in 1912. Spiral wound gaskets are manufactured by alternate layers of metal strip winding and non-metallic fillers spiral winding together into V-shaped, providing the gasket with mechanical resistance and resilience. It can be used for sealing flange joints, tube covers, boilers, heat exchangers, pressure vessels and valves. There are also some other shapes of strip winding, such as W & SU spiral wound gaskets. The spiral wound gasket normally includes the parts of outer centering ring and inner ring, it can reinforce the power of gasket. They are ideal for oil, steam, liquids, acids, various organic mediums and solvents.

Spiral Wound Gaskets e1540997746580 - Types of Gaskets

The diameter of a spiral wound gasket may range between a few mm up to 5.000 mm, and the spiral wound gasket thicknesses ranges from 3.2, 4.5, 6.4, to 7.2 mm.
A Spiral wound gasket may be ordered in different shapes, such as oblong, rectangular, oval, pear and diamond.

ASME B16.20 is the spiral wound gasket specification.

The round type is, of course, the standard shape for raised face (RF), male-and-female (M&F), and tongue-and-groove flanges (T&G) for petrochemical applications.

Spiral Wound Gasket Types

The standard spiral wound gasket can be categorized in four styles: reinforce (Style R), inner ring with reinforce (Style RIR), centering gasket (Style CG), centering gasket with inner ring (Style CGI).

spiral wound gasket style r - Types of Gaskets

Style R spiral wound gasket.

spiral wound gasket style rir - Types of Gaskets

Style RIR spiral wound gasket.

spiral wound gasket style cg - Types of Gaskets

Style CG spiral wound gasket.

spiral wound gasket style cgi - Types of Gaskets

Style CGI spiral wound gasket.

1) Style R
Style R is the basic type of spiral wound gasket. Style R’s inner diameter and outer diameter has a few laps metal strips that do not fill the fillers. They maintain the compression and sealing. The Style R spiral wound gasket is normally used for tongue and groove, male and female type joint of flanges.
2) Style RIR
The inner ring is between the bore diameter and the inner diameter of the gasket. It is designed to prevent accumulation of solids, reduce turbulent flow of process fluids and minimize erosion at flange faces. It’s used for male and female flanges.
3) Style CG
The centering ring accurately make the spiral ring on flange face. It provides an extra radial strength to protect the spiral ring. Style CG gaskets are suitable for flat face flange and raised face flange.
4)Style CGI
The style CGI spiral wound gasket is combined the advantages of centering ring and inner ring. Suitable for high temperature and high pressure. It can be used for above Class 900, corrosive medium or other harsh working conditions.
Spiral wound gaskets also have some other special types gasket,  like style HE, style 625 and etc. It can be used in special application.

Manufacturing Technique

The production of strip winding contain four step: cutting, forming, winding and spot welding. Gasket including reinforcing ring need extra processes of fabrcating and assembling. The inner and outer windings shall have a minimum of three plies of performed metal strip without filler. The initial two plies of inner windings shall have spot welds spaced around the inner circumference. The minium welds shall be three. The outer windings has a minimum of three welds along the circumference of a circle. The metal strip in the winding shall be 0.15-mm(0.006-in.) to 0.23-mm (0.009-in.) thick. The filler material thickness shall be determined by the manufacturer. The inner ring thickness shall be from 2.97 mm to 3.33 mm (0.117 in. to 0.131 in.). The inner ring inside diameter may extend a maximum of 1.5mm(0.06 in.) into the flange bore.

Spiral Wound Gasket Materials

spiral wound gasket - Types of Gaskets

Spiral Winding Materials

The sealing element of a spiral wound gasket is produced by interleaving plies of alternating metal winding strip combined with a filler material. The formed metal strip in the key sealing element of this type of semi-metallic gasket.

The most common winding materials are:

  • SS 304L
  • SS 316L
  • SS 321
  • Titanium
  • Nickel
  • Nickel alloys
  • Duplex

Filler Materials

Filler materials are used to enhance the conformability and the resilience of a spiral wound gasket. The most used filler material is graphite, however, other filler materials may be used depending on the application:

  • Graphite
  • PTFE
  • Ceramic fibers
  • Non-asbestos

Inner and Outer Rings Materials

The inner and the outer rings of a spiral wound gasket may be the same material of the winding core or a different one.

Solid inner rings are required by the ASME B16.20 specification for flanges with pressure rating 900# NPS 24 and larger, 1500# NPS 12 and larger, pressure class 2500#, NPS 4 and larger.

The inner ring improves the pressure rating of the spiral wound gasket, as it provides additional compression to the flanged joint and provides a heat and corrosion barrier protecting the gasket windings and the flanges from erosion.

Mechanical Properties

Spiral Wound Gasket Material
(Commercial Name)
DIN
SPECIFICATION
DIN
MATERIAL NR.
AISI &
UNS
B.S &
ASTM
HARDNESS
HV 10
TEMPERATURE RANGE in C° VOLUMETRIC MASS [G/CM3]
MIN. MAX.
Soft Iron (Armco) 1.1003 90 – 100 -60 500 7.85
Steel (LCS) RSt.37.2 1.0038 100 – 130 -40 500 7.85
Stainless Steel 304 X5CrNi 18 1.4301 304 304S15/16/31 130 – 180 -250 550 7,9
Stainless Steel 304 L X2CrNi 189 1.4306 304L 304S11 130 – 190 -250 550 7,9
Stainless Steel 309 X15CrNiMo 2012 1.4828 309 309S24 130 – 190 -100 1000 7,9
Stainless Steel 316 X5CrNiMo 1810 1.4401 316 316S31/33 130 – 180 -100 550 7,9
Stainless Steel 316 L X2CrNiMo 1810 1.4404 316L 316S11/13 130 – 190 -100 550 7,9
Stainless Steel 316 Ti X10CrNiMoTi 1810 1.4571 316Ti 320S31 130 – 190 -100 550 7,8
Stainless Steel 321 X10CrNiTi 189 1.4541 321 321S12/49/87 130 – 190 -250 550 7,9
Stainless Steel 347 X10CrNiNb 189 1.4550 347 347S31 130 – 190 -250 550 7,9
Nickel 200 Ni 99.2 2,4066 NO2200 3072-76 NA11 90 – 120 -250 600 8,9
Monel 400 NiCu 30 Fe 2.4360 NO4400 3072-76 NA13 110 – 150 -125 600 8,8
Inconel 600 NiCr 15 Fe 2.4816 NO6600 3072-76 NA14 120 – 180 -100 950 8,4
Incoloy 800 X10NiCrAITi 3220 1.4876 NO8800 3072-76 NA15 140 – 220 -100 850 8,4
Incoloy 825 NiCR 21 Mo 2.4858 NO8825 3072-76 NA 16 120 – 180 -100 450 8,14
Hastelloy B2 NMo 28 2.4617 N10665 170 – 230 -200 450 9,2
Hastelloy C276 ‘NiMo 16Cr15W 2.4819 N10276 170 – 230 -200 450 8.9
Titanium Ti 99,8 3.7025 110 – 140 -250 500 4,5

Characteristic of Spiral Wound Gasket

Spiral wound gaskets are widely used in various industries services. They are easiest to install, and suitable for the equipment, where the gasket suffering extreme temperature or pressure cycling, shock or vibration. Their solid construction provides stability and seallability even when the sealing surfaces are slightly corroded or bent.

Temperature & Color of Special Materials

Gaskets are color coded to help expedite the selection and identity of the gaskets. The color on the outside edge of the centering ring identifies both the winding and filler materials. The metallic winding material is designated by a solid color. The filler materials are designated by color stripes at equal intervals on the outside edge of the centering ring. Flexitallic color coding meets the industry standard for metal and filler materials listed in ASME B16.20.

Spiral wound gasket operating temperature with color codeing

Gasket Material Operating Temperature Gasket Color Code
Minimum
°F(°C)
Maximum
°F(°C)
304 Stainless Steel -320(-195) 1400(760) Yellow
316L Stainless Steel -150(-100) 1400(760) Green
317L Stainless Steel -150(-100) 1400(760) Maroon
321 Stainless Steel -320(-195) 1400(760) Turquoise
347 Stainless Steel -320(-195) 1400(760) Blue
Carbon Steel -40(-40) 1700(925) Silver
Alloy 20 -300(-185) 1000(540) Black
Hastelloy B2 -300(-185) 2000(1090) Brown
Hastelloy C276 -300(-185) 2000(1090) Beige
Monel 400 -200(-130) 1500(820) Orange
Nickel 200 -320(-195) 1400(760) Red
Titanium -320(-195) 2000(1090) Purple
Incoloy 800 -150(-100) 1600(870) White
Incoloy 825 -150(-100) 1600(870) White
Inconel 600 -150(-100) 2000(1090) Gold
Inconel 625 -150(-100) 2000(1090) Gold
Inconel X750 -150(-100) 2000(1090) No Color

Filler Materials.

Filler Material Operating Temperature Filler Color Code
Minium
°F(°C)
Maximum
°F(°C)
Ceramic -350(-212) 2000(1090) Light Green
Flexiable Graphite -350(-212) 910(510) Gray
PTFE -400(-240) 500(260) White
Mica Graphite -350(-212) 1400(760) Pink
Phyllosilicate -67(-55) 1800(1000) Light Blue

Centering ring doesn’t come into direct contact with fluid. It’s normally manufactured of carbon steel or painted to avoid corrosion. Other materials are available upon customers’ request. Inner ring is normally used the same material as the metal strip winding.

Manufacturer standard

Spiral wound gaskets are usually designed in accordance with ASME B16.20 and to suit with ASME B16.5, ASME B16.47 Series A&B, and BS1560 flanges, it is also designed in accordance with EN1514-2 to suit with EN1092-1. Spiral wound gasket can be also manufactured in other non-standard shapes like oval and oblong. The customer should provide the inside dimnesions, width and thickness.

ASME STANDARDS

  • Nonmetallic gasket dimensions and tolerances in accordance with ASME B16.21 for ASME B16.5 and ASME B16.47 flanges.
  • Standard thicknesses are 1/16″ and 1/8″, but others are available.
  • Spiral wound gaskets for ASME B16.5 1/4″ to 24″ dimensions and tolerances in accordance with ASME B16.20.
  • Spiral wound gaskets for ASME B16.47 22″ to 60″ Series A (MSS SP-44) dimensions and tolerances in accordance with ASME B16.20.
  • Spiral wound gaskets for ASME B16.47 26″ to 60″ Series B (API Std 605) dimensions and tolerances in accordance with ASME B16.20.
  • ASME B16.20 – Metallic Gaskets for Pipe Flanges: Ring-Joint, Spiral-Wound, and Jacketed
  • ASME B16.21 – Nonmetallic Flat Gaskets for Pipe Flanges
  • ASME B16.47 – Large Diameter Steel Flanges: NPS 26 Through NPS 60 Metric/Inch Standard
  • ASME B16.5 – Pipe Flanges and Flanged Fittings: NPS 1/2 through 24

ISO STANDARDS

  • ISO 4709 – Composition cork — Gasket material — Classification system, requirements, sampling, packaging and marking
  • ISO 7483 – Dimensions of gaskets for use with flanges to ISO 700

Spiral Wound Gasket Marking

The illustration shows the typical marking of spiral wound gaskets:

marking of SWG - Types of Gaskets

RING JOINT GASKETS

Ring joint gaskets are metallic sealing ring suitable for high pressure and high temperature applications. They are manufactured in two kinds of cross section: octagonal and oval accordance.

Ring joint gasket are used in connection with RTJ flange, generates a strong seal between two mating flanges. When the flanges are fixed by bolts, ring joint gasket is squeezed into the groove of the flange, forming a tight seal between the mating flanges. In order to avoid destruction of the flanges, the material of the ring joint gaskets must be softer than the material of the flanges.

ring joint gasket - Types of Gaskets

Ring Joint Gasket

Basic Types of Ring Joint Gaskets

Ring joint gaskets are manufactured in three types: Style R(including R octagonal gasket and R oval ring gasket), Style RX and Style BX. Style SRX and Style SBX are respectively as the adaptation version of Style RX and Style BX.

style r gasket 1 - Types of Gaskets

Style R Gasket

Style R gaskets  are divided into R octagonal gasket and R oval ring gasket according to the different cross section. Style R gasket is used for pressures up to 5,000 PSI. The ring gasket is regarded as semi-pressure energized ring gasket. They are manufactured in API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges.  Style R Ring Joint gaskets are manufactured in accordance with all relevant standards to suit the following flange designations:

API 6A > ASME / ANSI B16.5 > MSS SP44 ( ASME 16.47 SERIES A ) > BS 1560

R octagonal gasket is designed with octagonal-shaped section. The average diameter of the R octagonal gasket is slightly larger than the average diameter of the gasket groove. The angle between ring gasket and bevel face of gasket groove is around 23°. The octagonal shape fits only the modern flat bottom groove flange.

R oval ring gasket is manufactured in oval-shaped section. The oval ring fits the round and flat bottom ring groove flange. R octagonal gasket and R oval ring gasket in a similar function : they seal by an initial line contact or a edging action as the compressive forces are applied. However, the R oval ring gasket has a lower sealing efficiency than the octagonal ’s.

style rx gasket - Types of Gaskets

Style RX Gasket

Style RX gaskets comply with the standard of API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges. Style RX Gasket, as one special kind of octagonal gaskets is developed and improved in the basis of style R gasket. It has good sealing as the contact between gasket and the ring joint faces, especially the outside face, and is pressed tightly to keep good sealing performance. Style RX gasket is used for pressures up to 5,000 PSI. RX Ring Joint Gasket is one kind of pressure energized ring gaskets.

stylr bx gasket - Types of Gaskets

Style BX Gasket

Style BX, as one special kind of octagonal gaskets, is manufactured in accordance with API 6A and are suitable for use in high pressure API 6BX flanges. Style BX is designed for use on pressures up to 20,000 psi. All BX sizes have a pressure relief hole to equalise pressure across sealing faces. BX ring type joint gasket is one kind of pressure energized ring gaskets.

type srx sbx gasket - Types of Gaskets

Type SRX and SBX Gasket

Type SRX and SBX gaskets  are the same design as the Type RX and BX gaskets. They are manufactured to API 17D and apply for Subsea Wellhead and Tree Equipment. The “S” indicates these gaskets have cross-drilled holes to assure that any liquid trapped behind the ring gasket on either side will flow to the I.D. bore. SRX Ring Gaskets usually be designed in 6BX and/or 17D RTJ flanges under water.

Standards

Ring Joint Gaskets are manufactured according to any standard and non-standard sizes, including the standards of API 6A, API 17D, ASME B16.20, DIN 2693-67, JPI-7S-23-72 and other standards to suit ASME B16.5, ASME B16.47 Series A & Series B, API 6A Type 6B and 6BX flanges.

Applications

• Oil and gas industry
• Petrochemical industry
• Power plant technology
• Flange connections
• Pipe connections
• Heat exchangers, valves, pumps, compressors, boilers and other types of industrial equipment

Technical Literature of Ring Joint Gasket

  • Surface Finish

Style R and RX gaskets shall have a surface finish not rougher than 1.6μm (63μin.) roughness. Style BX gaskets shall have a surface finish not rougher than 0.8μm (32μin.) roughness.

RTJ GASKET MATERIALS

The material of RTJ gaskets shall match the flanges material but must have a lower hardness: this to ensure that the gasket, and not the flange, get plastically deformed within the groove of the flange as the two mating flanges are bolted together.

In case a harder material for the ring type joint is used, the groove of the flange would be damaged as the flanges are tightened (the hardness values for ring joint gaskets are given below).

Types of Materials for Ring Joint Gaskets

RTJ GASKET MATERIAL RING ID ASTM GRADE DIN GRADE WKSTOFF NUMBER AISI
GRADE
BS
GRADE
OTHER SPECS
Soft Iron D 1.1003 / 1.0335 Aramco / StW24
LCS S 1.1003 / 1.0335 Aramco / StW24
CS360 LT CS360LT A516 Gr70
4140 4140 UNS G41400 42CrMo4 1.7225 4140
F5 F5 UNS K42544 12CrMo195 1.7362 5Cr 1/2Mo
SS304 S304 S30400 X5CrNi 18 9 1.4301 304 304S15
SS304L S304L S30403 X2CrNi 18 9 1.4306 304L 304SS12
SS309 S309 S30900 X15CrNiSi2012 1.4828 309 309S24
SS310 S310 S31008 XX15CrNiSi2520 1.4841 310 310S24
SS316 S316 S31600 X5CrNiMo18 10 1.4401 316 316S16
SS316L S316L S31603 X2CrNiMo18 10 1.4404 316L 316S11/316S12
SS316L UREA S316UG S31603 X2CrNiMo 18 14 3 1.4435
SS316Ti S316Ti S31635 X10CrNiMoTi1810 1.4571 316Ti 320S31/320S17
SS321 S321 S32100 X10CrNiTi18 9 1.4541 321 321S12
SS347 S347 S34700 X10CrNiNb 18 9 1.455 347 347S51
SS410 S410 S41000 X10Cr13 1.4006 410 410S21
Monel 400 Monel400 N04400 NiCu30Fe 2.436
Inconel 600 INC600 N06600 NiCr15Fe 2.4816
Inconel 625 INC625 N06625 NiCr22Mo9Nb 2.4856
Inconel 718 INC718 N07718
Incoloy 800 INC800 N08800 X5NiCrAlTi31-20 1.4958
Incoloy 800H INC800H N08810 1.4958
Incoloy 825 INC825 N08825 NiCr21Mo 2.4858
904L 904L N08904 X1NiCrMoCu25-20-5 1.4539
F51 F51 S31803 X2CrNiMoN22-5-3 1.4462 2205 /Duplex
F53 F53 S32750 X2CrNiMoN25-7-4 1.441
F55 F55 S32760 X2CrNiMoCuWN 25 7 4 1.4501 Zeron 100
F60 F60 S32205 Duplex
Titanium Ti R 50400 3.7035
17-4PH 17-4PH S17400 1.4542 630
S254 S254 S31254 X1CrNiMoCuN20-18-7 1.4547 F44 / 6Mo
C276 C276 N10276 NiMo16Cr15W 2.4819 Hastelloy
Alloy 28 Alloy28 N08028 X1 NiCrMoCuN 31 27 4 1.4563 SANICRO 28

Mechanical Properties Ring Joint Gaskets Materials

Maximum Hardness of RTJ Gaskets

RTJ Gasket Material

Brinell HRB ID

Soft Iron-S

90 56 D

Low Carbon Steel

120 68 S

4 – 6% Chrome
1/2% Moly

130 72 F5

SS 304 Stainless Steel

160 83 S304

SS 316 Stainless Steel

160 83 S316

SS 347 Stainless Steel

160 83 S347

SS 410 Stainless Steel

170 96 S410

A Kammprofile gasket is manufactured by applying a sealing layer in non-metallic materials (such as graphite, PTFE-Teflon, ceramic fibers, non-asbestos, Mica, etc) or metallic materials (as aluminum or silver) on both sides of a metal core featuring concentric grooves of 1 mm Cam-Pitch. This sealing product, called also “grooved metal gasket” or “corrugated metal gasket”,  is used for high-pressure and temperature oil & gas applications.

 kamprofile - Types of Gaskets

Kammprofile gaskets fit smooth and stock flange surface finish (3.2 to 6.3 μm Ra, i.e. 125-250 RMS).
The common thickness of a Kammprofile gasket is between 2 and 4 mm (3 mm is the most common specification in petrochemical applications).
A Kammprofile gasket offers several benefits, due to its wide sealing area and construction:
  • May resist temperatures up to approx. 1000°C (the Kammprofile temperature rating depends on the materials of the metal core and the sealing layer)
  • May rate up to 250 bars, which is a considerable pressure rating
  • The gasket does not damage the flange surface, due to the protection offered by the sealing layer
  • The gasket can absorb fluctuations in temperature and pressure
  • It is more tolerant than Spiral Wound Gaskets to improper bolting torques
  • Suits both light and heavyweight flanges, even of large sizes
  • After assembly, the thickness of the sealing material is extremely low (0.1 – 0.2 mm), thus reducing leaks and failure rates
  • The core of a Kammprofile gasket can be re-used after cleaning and fitting the gasket with a new layering material. This is critical for expensive applications, such as heat exchanger gaskets that are made of exotic, expensive, materials (Inconel, Monel, Hastelloy, and Cupronickel).

camprofile gasket - Types of Gaskets

An outer metallic (integral or floating) ring may be added to the gasket, to facilitate the centering of the gasket during the installation on a flange. The sealing layers protect the flange surface and reinforce the seal.

KAMMPROFILE GASKET TYPES

Kammprofile gaskets are available in two main configurations, parallel root cores/convex root cores, and two designs (with/without loose outer centering ring), as shown in the image below:

kammprofile gaskets types - Types of Gaskets

KAMMPROFILE GASKET MATERIALS

Metal Core Materials

The core material of a Kammprofile gasket shall match the material of the piping system

Kammprofile Core Materials DIN
Designation
DIN Material Number AISI ASTM UNS
Designation
British Standard
Designation
Hardness
HB/HV
Temperature in C°
Min.           Max.
Density in gr/cm3
Soft Iron 90  –  100 –  60 500 7.85
Steel (LCS) RSt. 37.2 1.0038 100  –  130 –  40 500 7.85
Stainless Steel 304 X5 CrNi 1810 1.4301 304 304S15/16/31 130  –  180 -250 550 7.9
Stainless Steel 304 L X2CrNi 1911 1.4306 304L 304S11 130  –  190 -250 550 7.9
Stainless Steel 309 X15CrNiSi 2012 1.4828 309 309S24 130  –  190 -100 1000 7.9
Stainless Steel 316 L(1) X2CrNiMo 1713 1.4404 316L 316S11/13 130  –  190 -100 550 7.9
Stainless Steel 316 Ti X6CrNiMoTi 1712 1.4571 316Ti 320S31 130  –  190 -100 550 7.8
Stainless Steel 321 X6CrNiTi 1810 1.4541 321 321S12/49/87 130  –  190 -250 550 7.9
Stainless Steel 347 X6CrNiNb 1810 1.4550 347 347S31 130  –  190 -250 550 7.9
Aluminium Al 99,5 3.0255 20  –    23 -250 300 2.73
Silver 28* -250 750 10.5
Copper 2.0090 50  –    80 -250 400 8.9
Nickel 200 Ni 99,2 2.4066 N02200 3072-76 NA11 90  –  120 -250 600 8.9
Monel 400 ® NiCu 30 Fe 2.4360 N04400 3072-76 NA13 110  –  150 -125 600 8.8
Inconel 600 ® NiCr 15 Fe 2.4816 N06600 3072-76 NA14 120  –  180 -100 950 8.4
Incoloy 800 ® X10NiCrAITi 3220 1.4876 N08800 3072-76 NA15 140  –  220 -100 850 8.0
Incoloy 825 ® NiCr 21 Mo 2.4858 N08825 3072-76 NA16 120  –  180 -100 450 8.14
Hastelloy B2 ® NiMo 28 2.4617 N10665 170  –  230 -200 450 9.2
Hastelloy C276 ® NiMo16Cr15W 2.4819 N10276 170  –  230 -200 450 8.9
Titanium Ti 99,8 3.7025 110  –  140 -250 350 4.5

Sealing Layer

The most common layer materials for Kammprofile gaskets are graphite and PTFE (Teflon).
The advantages of a graphite layering material are:

  • Excellent gas tightness qualities
  • Non-aging properties
  • Very good chemical resistance
  • Resistance to high (fluctuating) temperatures and pressures

PTFE is also used due to its excellent chemical resistance, resistance to temperatures up to 250°C  and excellent sealing properties for gas applications.

Sealing Layer Material for Kammprofile Temperature in C°
Min.     Max.
Max. operating pressure in Bars Gas tightness Recommended Application
Graphite -200 550 250 Good Aggressive media
PTFE (Teflon ® ) -200 250 100 Good Aggressive media
Non-asbestos -100 250 100 Good Gas and liquids
Silver -200 750 250 Good Aggressive media

KAMMPROFILE GASKET DIMENSIONS

Class 150-400

Kammprofile gasket dimensions for AMSE B16.5 flanges

camprofile - Types of Gaskets

NPS d1 d2 d3
150 300 400
1/2 23 33.3 44.4 50.8 50.8
3/4 28.6 39.7 53.9 63.5 63.5
1 36.5 47.6 63.5 69.8 69.8
44.4 60.3 73 79.4 79.4
52.4 69.8 82.5 92.1 92.1
2 69.8 88.9 101.6 108 108
82.5 101.6 120.6 127 127
3 98.4 123.8 133.4 146.1 146.1
111.1 136.5 158.8 161.9 158.7
4 123.8 154 171.5 177.8 174.6
5 150.8 182.6 193.7 212.7 209.5
6 177.8 212.7 219.1 247.7 244.5
8 228.6 266.7 276.2 304.8 301.6
10 282.6 320.7 336.5 358.8 355.6
12 339.7 377.8 406.4 419.1 415.9
14 371.5 409.6 447.7 482.6 479.4
16 422.3 466.7 511.2 536.6 533.4
18 479.4 530.2 546.1 593.7 590.5
20 530.2 581 603.2 650.9 644.5
24 631.8 682.6 714.4 771.5 765.2

All values in millimeters

Class 600-2500

Kammprofile gasket dimensions for AMSE B16.5 flanges

camprofile - Types of Gaskets

NPS d1 d2 d3
600 900 1500 2500
1/2 23 33.3 50.8 60.3 60.3 66.7
3/4 28.6 39.7 63.5 66.7 66.7 73
1 36.5 47.6 69.8 76.2 76.2 82.5
44.4 60.3 79.4 85.7 85.7 101.6
52.4 69.8 92.1 95.2 95.2 114.3
2 69.8 88.9 108 139.7 139.7 142.8
82.5 101.6 127 161.9 161.9 165.1
3 98.4 123.8 146.1 165.1 171.5 193.7
111.1 136.5 158.7
4 123.8 154 190.5 203.2 206.4 231.7
5 150.8 182.6 238.1 244.5 250.8 276.2
6 177.8 212.7 263.5 285.8 279.4 314.3
8 228.6 266.7 317.5 355.6 349.3 384.1
10 282.6 320.7 369.9 431.8 431.8 473
12 339.7 377.8 454 495.3 517.5 546.1
14 371.5 409.6 488.9 517.5 574.7
16 422.3 466.7 561.9 571.5 638.1
18 479.4 530.2 609.6 635 701.7
20 530.2 581 679.5 695.3 752.4
24 631.8 682.6 787.4 835 898.5

All values in millimeters

JACKETED GASKET

A Jacketed gasket features an inner soft material core and an outer metallic shell. The inner filler material provides resilience to the gasket, whereas the metal jacket protects the inner core of the gasket and withstands the pressure, the temperature, and the corrosion of the process.

Metal jacket gaskets are available with a single or double jacket and are widely used for pumps, valves, pressure vessels, and other mechanical equipment.
A metal jacket gasket requires flat face flanges with a smooth face finish to seal effectively.

The size range and thickness tolerances for this type of gaskets are covered by ASME B16.21 specification:

  • OD: Less than 5,000mm
  • Thickness: 2~8mm with tolerance +0.03 inch. to -0.000 inch (+0.8mm, -0.0mm)

 jacketed gasket - Types of Gaskets

JACKETED GASKET MATERIALS

Metal Jacket Materials

The table shows the most common metals used for jacketed gaskets and the recommended temperature range:

Jacket Materials Hardness HB Temp.℃
Carbon Steel 90 -60~+450
304 (L) 130 -270~+550
316 (L) 130 -270~+550
321 130 -270~+550
Monel 110 -60~+500
Inconel 90 -60~+600
AL 30 -250~+300
CU 80 -250~+400

Inner Core Materials

Metal jacket gaskets have a soft inner core, which may be manufactured in materials as:

  • Non-Asbestos millboard and other non-asbestos materials (aramid, glass fiber, inorganic fibers, etc)
  • CAF
  • Rubber
  • PTFE
  • Graphite

JACKETED GASKET TYPES

The two main types of metal jacketed gasket are the single and the double jacket designs. Besides these two basic types, other designs are available on the market as illustrated below:

mjg type105 - Types of Gaskets Double Jacketed Corrugated
— soft filler

Reduced contact area, enhances compression characteristics, suitable for uneven flanges.
mjg type106 - Types of Gaskets Double Jacketed Corrugated
— metal filler

Usually stainless outer casing with soft iron filler ring.
Core material available St. St. -304.316L.321
Soft iron, Monel, Inconel
mjg type107 - Types of Gaskets Single Corrugated
— asbestos rope filler

Typically used on very poor or pitted flanges, low bolt loading requirement.
mjg type108 - Types of Gaskets Metal Jacket Laminates
— soft filler

Combines flexible graphite with stainless steel core material
mjg type109 - Types of Gaskets Solid metal ring machined on each contact face to provide a serrated surface finish covered with Graphite.
PTFE Nonas or Asbestos.
mjg type100 - Types of Gaskets Double Jacketed – soft filler
Used on high-temperature pressure applications or where corrosion problems may exist
mjg type101 - Types of Gaskets Single Jacketed – metal filler
– partly enclosed

Very seldom used, old design. Used in applications where poor or pitted flanges exist on one facing.
mjg type102 - Types of Gaskets Single Jacketed – Soft filler
– partly enclosed

Used on narrow flanges
mjg type103 - Types of Gaskets Single Jacketed – Soft filler
– open outside edge

Used in narrow flanges, protection of filler cleared for by casing
mjg type104 - Types of Gaskets Single Corrugated – no filler
Used mainly in valve applications, small recess gap. Sometimes referred to as Taylor ring.

JACKETED GASKET DIMENSIONS

Class 150-400

metal jacketed - Types of Gaskets

Jacketed gasket dimension

NPS d1 d2
150 300 400
1/2 23.8 44.5 50.8 50.8
3/4 31.8 54 63.5 63.5
1 36.5 63.5 69.9 69.9
46 73 79.4 79.4
52.4 82.6 92.1 92.1
2 73.2 101.6 108 108
85.9 120.6 127 127
3 107.8 133.4 146.1 146.1
4 131.8 171.5 177.8 174.7
5 152.4 193.8 212.8 209.5
6 190.5 219.1 247.7 244.5
8 238.3 276.3 304.8 301.7
10 285.8 336.6 358.8 355.6
12 342.9 406.4 419.1 415.9
14 374.7 447.7 482.6 479.5
16 425.5 511.2 536.6 533.4
18 489 546.1 593.7 590.6
20 533.4 603.3 650.9 644.5
24 641.4 714.4 771.6 765.3
NPS d1 150 300 400

Class 600-2500

Jacketed gasket dimensions for AMSE B16.5 flanges

metal jacketed - Types of Gaskets

NPS d1 d2
600 900 1500 2500
1/2 23.8 50.8 60.4 60.4 66.8
3/4 31.8 63.5 66.7 66.7 73.1
1 36.5 69.9 76.2 76.2 82.5
46 79.4 85.8 85.8 101.6
52.4 92.1 95.3 95.3 114.3
2 73.2 108 139.7 139.7 143
85.9 127 161.9 161.9 165.1
3 107.8 146.1 165.1 171.5 193.8
4 131.8 190.5 203.2 206.5 231.9
5 152.4 238.2 244.6 250.9 276.3
6 190.5 263.6 285.8 279.4 314.5
8 238.3 317.5 355.6 349.3 384.3
10 285.8 396.9 431.8 431.8 473.2
12 342.9 454.1 495.3 517.6 546.1
14 374.7 489 517.6 574.7
16 425.5 562 571.5 638.2
18 489 609.6 635 701.8
20 533.4 679.5 695.5 752.5
24 641.4 787.4 835.1 898.6

HOW TO ORDER A METAL JACKETED GASKET

The following information should be provided to the gasket supplier to order a jacket-gasket properly:

  • Outside diameter
  • Inside diameter (NPS)
  • Shape per standard index
  • Type Number
  • Thickness
  • Materials (metal or metal filler)
  • Bar size
  • Radii
  • Distance from the centerline of the gasket to the centerline of bars

Graphite High-strengthen Composite Gasket

1. Made of die cutting the metal-strengthening expansion graphite slab and can be processed to be internal wrapped border and external wrapped border. The general thickness is 1.5mm, 3.0mm, 2.0mm, 4.0mm . 
operation temperature: 

  • Wrapped PTFE:   –200–200℃.
  • Carbons Steel:   10–450℃
  • SS304:   -240–560℃
  • SS316:   -200–870℃

2. Application: 
has very good sealing performance, low preloaded pressure, and not sticking to the flange sealing surface; used in the flange surface sealing of pipeline, valve, pump, pressure containers, heat exchanger, and reaction cauldron, etc. The film sticking PTEE can be used in food, pure water, and pharmacy sections.

graphite - Types of Gaskets

3. Technique Specification:

1). Working temperature: -200℃~650℃
2). Working pressure: 6.4~10.0MPa
3). Min. Pre-tightening specific pressure: y=30MPa
4). Gasket coefficient: m=2
5). Max.machinable size: ~2100mm

Serrated Metal Gasket

1. Process the metal flat gasket to teeth-shaped metal gasket of 90°contained angle. Internal and external positioning ring. To protect flange and ensure effective sealing, the surface sealing layer can be adhibited. The materials may be PTEE, graphite, and specially-processed silver and aluminum.
2. Choosing materials 

Soft steel, copper, silver, stainless steel, chrome steel, Monel alloy steel, alloy aluminum and other metal slabs or sticks are processed to be ring teeth-shaped surface after mechanical processing.

serrated metal gasket - Types of Gaskets

3. Relevant data 
Maximum operation pressure: 250Kg/cm3 
Minimum preloaded specific pressure: y>Kg/cm3700 Kg/m3
Gasket Coefficient : m >4.25
Maximum processing dimension: 3000MM

4. Application range 
Steam dynamo of power plant (or nuclear power plant), heat exchanger gasket or fully-sealing gasket of shipping dynamo and manhole gasket can be used in the high temperature and high pressure of chemical industry. 
5. Production reference (mm)
Outer diameter of gasket thickness T chimb thickness t distance between tooth peak P

BELOW 100
3.0
2.0
1.0
100—250
4.5
3.0
1.0
250—630
6.0
4.5
1.0
630–1600
8.0
6.0
1.0

6. Others:
the contact with other sealing surfaces is linear contact of many concentric circles, so very high pressing force is not needed to ensure good sealing, but the roughness of the sealing surface should be over Ra1.6um.

PTFE Envelope Gasket

1. Composite gasket of cladding other non-metal metal with PTFE, which does not only have the chemistry repellence performance of PTFE, but also have good tensile performance due to its core materials. It is indispensable in chemical industry and chemical devices.

2. Application: 
used in the convexity flange and plane pipe flange of high corrosive medium or high cleanness. With very good chemical repellence, it is often used in food processing industry and drinking water projects.

teflon glad gasket - Types of Gaskets
teflon glad gasket big 1 - Types of Gaskets

3. Temperature: -200—250℃

Gasket material
temperature ℃
pressure MPa
Asbestos clad plate
150
1
Non-asbestos clad plate
200
2
Copy plate between two layers of asbestos
Add one layer of asbestos plate in the middle
220
2.5
Copy plate between two layers of asbestos
Add one layer of asbestos plate in the middle
220
2.5

4. Types 
A. Dissection cut type 
It has a cladding mouth, so it is an economical gasket used in low pressure, and has very good effects on leveling, compressed metal, porcelain and glass sealing surface. It is also called cladding gasket of Y-type dissection. 
Cut it into 0.8MM—1MM ring-shaped sheet with cylinder material truck, divide it from the center of outer side thickness, put core materials into the cut mouth, which is about 1.5—2.0MM away from the inner hole.
B. Folding type 
It is cladding gasket of left frame-type dissection, with its inner diameter the same with that of flange, so as to prevent the liquid from whirlpooling in the flange, so the inside air has very small expansion amount and good sealing performance. This kind of gasket is often made of reinforcing materials of graphite, open asbestos and rubber. 
C. Mechanical processing type 
Often used in high-pressure medium, this kind of gasket is cladded with machines. The filling materials are generally constringent materials and rubber. The two ends of 0.4—0.8MM thick strap-shaped PTFE film are heated and covered outside the ring-shaped core materials, to show U shape.

5. Other Technique Specification:
PH VALUE: 0~14
GASKET COEFFICIENT: M=2.5MPA
MIN PRELOADED PRESSURE: Y=20.0MPA
MAX MECHANICAL SIZE: 1100MM.

PTFE Gasket

PTFE gasket is manufactured by molding method with PTFE granular resin. PTFE compared with other plastics, has a superior properties against chemicals and temperature. 
Because of such excellent properties, PTFE has a wide application as a sealing material.

ptfe gasket - Types of Gaskets

Specifications

No.

Type

Standard

Type

Standard

1

RF 10A

Φ53×Φ18×3t

FF 10A

Φ90×Φ18×3t

2

RF 15A

Φ58×Φ22×3t

FF 15A

Φ95×Φ22×3t

3

RF 20A

Φ63×Φ28×3t

FF 20A

Φ100×Φ28×3t

4

RF 25A

Φ74×Φ35×3t

FF 25A

Φ125×Φ35×3t

5

RF 32A

Φ84×Φ43×3t

FF 32A

Φ135×Φ43×3t

6

RF 40A

Φ89×Φ49×3t

FF 40A

Φ140×Φ49×3t

7

RF 50A

Φ104×Φ61×3t

FF 50A

Φ155×Φ61×3t

8

RF 65A

Φ124×Φ77×3t

FF 65A

Φ175×Φ77×3t

9

RF 80A

Φ134×Φ90×3t

FF 80A

Φ185×Φ90×3t

10

RF 90A

Φ144×Φ102×3t

FF 90A

Φ195×Φ102×3t

11

RF 100A

Φ159×Φ115×3t

FF 100A

Φ210×Φ115×3t

12

RF 125A

Φ190×Φ141×3t

FF 125A

Φ250×Φ141×3t

13

RF 150A

Φ220×Φ167×3t

FF 150A

Φ280×Φ167×3t

14

RF 200A

Φ270×Φ218×3t

FF 175A

Φ305×Φ192×3t

15

RF 225A

Φ290×Φ244×3t

FF 200A

Φ330×Φ218×3t

16

RF 250A

Φ333×Φ270×3t

FF 250A

Φ400×Φ270×3t

17

RF 300A

Φ378×Φ321×3t

FF 300A

Φ445×Φ321×3t

18

RF 350A

Φ423×Φ359×3t

FF 350A

Φ490×Φ359×3t

19

RF 400A

Φ486×Φ410×3t

FF 400A

Φ560×Φ410×3t

20

RF 450A

Φ541×Φ460×3t

FF 450A

Φ620×Φ460×3t

21

RF 500A

Φ596×Φ513×3t

FF 500A

Φ675×Φ513×3t

22

RF 600A

Φ700×Φ615×3t

FF 550A

Φ745×Φ564×3t

 

 

 

FF 600A

Φ795×Φ615×3t

Main properties

Properties

Unit

Result

Apparent density

g/cm3

2.10-2.30

Tensile strength (min)

MPa

15.0

Ultimate elongation (min)(min)

%

150

Corrugated Gasket

1. Reprocess the metal gasket to be wave-shaped (mechanical punching)
2. Suitable materials: 
Soft steel, stainless steel, galvanizaiton steel plate, chrome steel plate, copper, brass copper, Monel alloy.

corrugated gasket - Types of Gaskets

3. Thickness: 
0.3~3mm, the distance between wave peaks: 2.0—6.5mm

WIDHT (W)
DIAMETER (d)

WAVE CREST DISTANCE(P) MM

10–16

16–25

25–40

40–60

BELOW

2

3

3

3

100–160

3

3

3

3

160–250

3

3

4.5

4.5

250–400

3

3

4.5

4.5

400–630

3

4.5

4.5

4.5

630—1000

3

4.5

4.5

6.5

1000–1600

3

6.5

6.5

6.5

4. Application:
the preloaded pressure and soft asbestos rubber plates are mainly used in the sealing position of valve cover of brake valve, stop valve, and check valve, etc.

Source: China Gaskets Manufacturer – Yaang Pipe Industry (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

If you want to have more information about the article or you want to share your opinion with us, contact us at sales@steeljrv.com

Please notice that you might be interested in the other technical articles we’ve published:

  • How to get high quality Gaskets

  • How to install gaskets correctly

  • A Simple Introduction to Graphite Gaskets

  • What Are A, B, C, D , R, RIR, CG and CGI Types for Spiral Wound Gaskets

  • What is a gasket

  • What are gaskets

References:

  • www.projectmaterials.com
Summary
types of gaskets - Types of Gaskets
Article Name
Types of Gaskets
Description
According to its material and structural characteristics, gaskets can be divided into non-metal gaskets, metal gaskets, metal-non-metal composite gaskets, and various types can be subdivided into several types.
Author
Publisher Name
www.steeljrv.com
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