Gaskets

a piece of rubber or some other material that is used to make a tight seal between two parts that are joined together.

Gaskets are normally made from a flat material, a sheet such as   paper, rubber, silicone, metal, cork, felt,  neoprene, nitrile, rubber, fiberglass, plastic polymer (polychlorotrifluoroethylene).

The most common types of gaskets are:

  1. Ring Type Joints (RTJ)
  2. SWG (Spiral Wound Gaskets)
  3. Flange gaskets
  4. Metal Jacketed gaskets
  5. Kammprofile gaskets

 

  1. Ring Type Joints

R and RX Series

R Series ring type joint gaskets are available in oval and octagonal designs. The oval design can be used in older round bottom gland designs, while both can be used in a flat bottom design. R Series are available up to 5,000 PSI.

RX series are interchangable with R series octagonal gaskets designed for API 6B flanges. RX out perform R seriessituations that have higher pressures with more intense vibrations. RX gaskets are available up to 5,000 PSI.

 

BX Series

Type BX operates in 20,000 psi with non interchangeability. Type BX has a pressure passage hole for pressure equalization on each sealing face sides.

SBX Series

Derived from RX, BX are SRX, SBX in accordance with API 17D standards for usage in applications like subsea well heads etc.

Standard ANSI Flange Gasket Size Chart

Full Face and Ring Type Flange Gasket Dimensions

 

SIZE

Ring Gaskets

Full Face Gaskets

125-150 LB 250-300 LB 125-150 LB 250-300 LB
OD ID OD ID OD ID Holes Hole
Dia.
Bolt
Circle
Dia.
OD ID Holes Hole
Dia.
Bolt
Circle
Dia.
1/2″ 1  7/8 27/32 2  1/8 27/32 3  1/2 27/32 4 5/8 2  3/8 3  3/4 27/32 4 5/8 2  5/8
3/4″ 2  1/4 1  1/16 2  5/8 1  1/16 3  7/8 1  1/16 4 5/8 2  3/4 4  5/8 1  1/16 4 3/4 3  1/4
1″ 2  5/8 1  5/16 2  7/8 1  5/16 4  1/4 1  5/16 4 5/8 3  1/8 4  7/8 1  5/16 4 3/4 3  1/2
1  1/4″ 3 1  21/32 3  1/4 1  21/32 4  5/8 1  21/32 4 5/8 3  1/2 5  1/4 1  21/32 4 3/4 3  7/8
1  1/2″ 3  3/8 1  29/32 3  3/4 1  29/32 5 1  29/32 4 5/8 3  7/8 6  1/8 1  29/32 4 3/4 4  1/2
2″ 4  1/8 2  3/8 4  3/8 2  3/8 6 2  3/8 4 3/4 4  3/4 6  1/2 2  3/8 8 7/8 5
2  1/2″ 4  7/8 2  7/8 5  1/8 2  7/8 7 2  7/8 4 3/4 5  1/2 7  1/2 2  7/8 8 7/8 5  7/8
3″ 5  3/8 3  1/2 5  7/8 3  1/2 7  1/2 3  1/2 4 3/4 6 8  1/4 3  1/2 8 7/8 6  5/8
3  1/2″ 6  3/8 4 6  1/2 4 8  1/2 4 8 3/4 7 9 4 8 7/8 7  1/4
4″ 6  7/8 4  1/2 7  1/8 4  1/2 9 4  1/2 8 3/4 7  1/2 10 4  1/2 8 7/8 7  7/8
4  1/2″ 7 5 7  5/8 5 9  1/4 5 8 3/4 7  3/4 10  1/2 5 8 7/8 8  1/2
5″ 7  3/4 5  9/16 8  1/2 5  9/16 10 5  9/16 8 7/8 8  1/2 11 5  9/16 8 7/8 9  1/4
6″ 8  3/4 6  5/8 9  7/8 6  5/8 11 6  5/8 8 7/8 9  1/2 12  1/2 6  5/8 12 7/8 10  5/8
7″ 10 7  5/8 10  7/8 7  5/8 12  1/2 7  5/8 8 7/8 10  3/4 14 7  5/8 12 7/8 11  7/8
8″ 11 8  5/8 12  1/8 8  5/8 13  1/2 8  5/8 8 7/8 11  3/4 15 8  5/8 12 1 13
9″ 12  1/2 9  5/8 12  7/8 9  5/8 15 9  5/8 12 7/8 13  1/4 16  1/4 9  5/8 12 1 14
10″ 13  3/8 10  3/4 14  1/4 10  3/4 16 10  3/4 12 1 14  1/4 17  1/2 10  3/4 16 1  1/8 15  1/4
12″ 16  1/8 12  3/4 16  5/8 12  3/4 19 12  3/4 12 1 17 20  1/2 12  3/4 16 1  1/4 17  3  4
14″ 17  3/4 14 19  1/8 14 21 14 12 1  1/8 18  3/4 23 14 20 1  1/4 20  1/4
15′ 19 15 22  1/4 15 16 1  1/8 20
16″ 20  1/4 16 21  1/4 16 23  1/2 16 16 1  1/8 21  1/4 25  1/2 16 20 1  3/8 22  1/2
18″ 21  5/8 18 23  1/2 18 25 18 16 1  1/4 22  3/4 28 18 24 1  3/8 24  3/4
20″ 23  3/8 20 25  3/4 20 27  1/2 20 20 1  1/4 25 30  1/2 20 24 1  3/8 27
22″ 26 22 27  3/4 22 29  1/2 22 20 1  1/4 27  1/4 33 22 24 1  3/8 29  1/4
24″ 28  1/4 24 30  1/2 24 32 24 20 1  3/8 29  1/2 36 24 24 1  5/8 32
26″ 30  1/2 26 32  7/8 26 34  3/4 26 24 1  3/8 31  3/4 38  1/4 26 28 1  5/8 34  1/2
28″ 32  3/4 28 35  3/8 28 36  1/2 28 26 1  3/8 34 40  3/4 28 28 1  5/8 37
30″ 34  3/4 30 37  1/2 30 38  3/4 30 28 1  3/8 36 43 30 28 1  7/8 39  1/4
32″ 38 32 39  5/8 32 41  3/4 32 28 1  5/8 38  1/2 45  1/4 32 28 1  7/8 41  1/2
34″ 39 34 41  5/8 34 43  3/4 34 32 1  5/8 40  1/2 47  1/2 34 28 1  7/8 43  1/2
36″ 41  1/4 36 44 36 46 36 32 1  5/8 42  3/4 50 36 32 2  1/8 46
38″ 43  5/8 38 46  1/8 38 48  3/4 38 36 1  5/8 45  1/4 52  1/4 38 32 2  1/8 48
40′ 45  5/8 40 48  3/4 40 50  3/4 40 36 1  5/8 47  1/4 54  1/4 40 36 2  1/8 50  1/4
42″ 48 42 50  3/4 42 53 42 36 1  5/8 49  1/2 57 42 36 2  1/8 52  3/4
44″ 50  1/8 44 53 44 55  1/4 44 40 1  5/8 51  3/4 59  1/4 44 36 2  1/8 55
46″ 52  1/8 46 55  1/4 46 57  1/4 46 40 1  5/8 53  3/4 61  1/2 46 40 2  1/8 57  1/4
48″ 54  1/2 48 58  3/4 48 59  1/2 48 44 1  5/8 56 65 48 40 2  1/8 60  3/4

 

2.Spiral Wound Gaskets (SPW Gaskets)

The main property of Spiral Wound Gasket, owing to elastic action of the special metallic strip profile, is that of offering a perfect sealing under fluctuating pressure and temperature conditions & maintaining tight elastic recovering. This elasticity can be modified by a proper selection of components.

 

 

Flexitallic Gaskets

SPW Gaskets

 

Type Construction Use & Suitability
Type R Inner and outer diameter reinforced with plies of metal without filler Greater stability and better compression characteristics. Tongue & groove /male & female/groove to flat face flange assemblies.
Type RIR Solid inner metal ring as compression stop to fill annular space between flange bore & inside diameter of gasket. Prevent accumulation of solids, reduce process fluids turbulent flow and minimize flange face erosion. Suitable for male and female pipe flanges.
Type CG External ring centering gasket on flange face for more radial strength. Prevent gasket blowout, compression stop. Suitable for Flat & raised face flanges
Type CGI Solid metal Inner ring acc. to ASME B16.20 for class 900, 1500, 2500, NPS greater than 24”, 12”, 4” resp. & metal winding of same material. Suction side of pumps /compressors, smooth surface finish (125 Ra max), prevent over compression of gasket. Suitable for Flat & raised face flanges, corrosive/ toxic media, high press. /high temp. Service.
Type HE Standard spiral wound on outer portion & single or double jacketed for pass bar, fastened to ID of spiral wound portion. As Heat exchanger gaskets with heat exchangers requiring pass bars.
Type HE-CG Similar to Type HE with outer guide ring & spiral wound primary seal. Resiliency and excellent sealing quality.
Type HE-CGI Varied CGI with an inner ring & spiral wound steel nose/ solid metal outer ring. Accurate gasket location. Used in Heat exchangers, TEMA type flange arrangements.
Type CG-RJ Special sized CG gasket with outer ring to cover ring joint grooves. Maintenance repair item prevents SPW portion from entering groove & suitable for Standard ring joint flanges.
Type M, MC, MCS MC has Pre-formed inner &/or outer rings of spiral winding with a centering guide. MCS has a solid metal inner &/or outer ring. Boiler manholes cover assembly, high pressure systems. Depending on manhole plate configuration these are oval, round, obround in shape & prevent shouldering and pinching due to radial misplacement.
Type T Round, oval, square, diamond, obround, pear shaped gaskets. Boiler hand hole & tube cap assemblies. Relies on internal pressure in boiler to seat the gasket.
Type 625 Similar to Type R & 0.0625” thick. High pressure sealing in space restricted applications.
Carrier Ring Integral construction of 2 spiral wound gaskets placed in a specially machined metallic ring. High recovery & Ease of handling.

 

3.Flange gasket

Flange 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.

Image result for flange gasket

Flange gasket

4.METAL JACKETED GASKETS

Metal Jacketed gaskets, as the name suggests, are comprised of a metallic outer shell with either a metallic or non-metallic filler. The filler material gives the gasket resilience, while the metal jacket protects the filler and resists pressures, temperatures and corrosion.

They are used for Heat Exchanger applications, pumps and Valves, however the resilience and recovery properties of these gaskets are limited. Metal Jacketed gaskets require smooth flange surface finishes, high bolt loads and flange flatness in order to seal effectively.

 

Related imageMETAL JACKETED GASKETS

 

 

5.Kammprofile gaskets

Kammprofile gaskets are recognized as a problem solver for heat exchangers, large vessels, and equipment that experience excessive movement due to thermal expansion. The Kammprofile provides one of the tightest seals combined with superior load bearing characteristics. Kammprofile gaskets consist of a sealing core metal with or without guide ring.

Related image

Kammprofile gaskets