Semi-Metallic Gaskets

STYLE 911, 911M, 911T and 914
Application / Service
For applications with high temperature variations (thermal cycling), and/or pressure variations, and/or flange rotation problems etc., gaskets with adequate residual stress (stress retention), flexibility and recovery are needed. QUEST spiral-wound gaskets have been designed to meet these demanding requirements.
STYLE 913 and 913M
Spiral Wound Metalflex® Styles
Application / Service
For applications with high temperature variations (thermal cycling), and/or pressure variations, and/or flange rotation problems etc., gaskets with adequate residual stress (stress retention), flexibility and recovery are needed. QUEST spiral-wound gaskets have been designed to meet these demanding requirements.Double Jacket Gaskets

Description
Metal Jacketed Gaskets consist of soft filler material encapsulated in a metallic material. The filler material provides the gasket with compressibility and resilience while the jacket provides compressive strength and blow out resistance.
Metallic Jacket
Almost any metal or alloy found in sheet form can be used as a jacket; its choice must take into consideration the fluid to be sealed. The metallic jacket is 0.016 in (0.4 mm) to 0.020 in (0.5 mm) thick.
Filler
The standard filler material is Flexible Graphite. Other fillers like ceramic, mica-graphite, PTFE or another metal can be used.
Design
The following recommendations are based on successful practical applications:
Gaskets confined by the inside and outside diameters:
- Gasket inside diameter = groove inside diameter plus 1/16 in (1.6 mm).
- Gasket outside diameter = groove outside diameter less 1/16 in (1.6 mm).
Gaskets confined by outside diameter:
- Gasket inside diameter = flange inside diameter plus a minimum of 1/8 in (3.2 mm).
- Gasket outside diameter = groove outside diameter less 1/16 in (1.6 mm).
Non confined gaskets:
- Gasket inside diameter = flange inside diameter pIus 1/8 in (3.2 mm).
- Gasket outside diameter = bolt circle diameter less bolt diameter.
Styles And Applications
STYLE 920 The style 920 is a round single jacket gasket. Used in applications where the seating stress and width are limited. It can be manufactured in circular or oval shape. The maximum gasket width is 1/4 (6.4 mm) and the standard thickness is 3/32 in (2.4 mm).
STYLE 923 The style 923 is a flat double jacket gasket. Its most typical applications are as pipe flange gaskets and in Heat Exchangers. ASME B 16.20 shows the gasket dimensions for ANSI B 16.5 flanges. The standard thickness is 1/8 in (3.2 mm). This style is also used in large size reactors in chemical plants. Another important use is for flanges in the large, low pressure ducting in Steel Mill Blast Furnaces. To compensate for distortions and irregularities of these flanges gaskets have the thickness from 5/32 in (4 mm) to 1/4 in (6 mm).
STYLE 926 Similar to style 923 but the metallic jacket is corrugated. The corrugations act as a labyrinth increasing the sealability. For ASME B 16.5 flanges, the gasket dimensions are also covered by the ASME B 16.20 standard.
STYLE 929 Similar to style 926 with a grooved metallic filler. Used in applications where it is necessary to have a gasket without non-metallic materials, temperature limits and chemical resistance depend upon of the metal only.
Corrugated Metal (CMG)
STYLE 905

Description
Corrugated Metal Gaskets consist of a corrugated stainless metal core, with a soft facing layer applied to each face. The corrugations provide resilience and reduce the sealing surface area of the gasket while the soft layer ensures outstanding sealing, even at low loads. Particularly suited as a replacement to metal jacketed gaskets.
Style 905 Corrugated Gaskets For ASME B16.5 Flanges
Style 905 gaskets with Flexible Graphite facings have gained popularity in the marketplace in Class 150 and 300 ASME B16.5 flanges due to its ability to seal at low bolt loads. Style 905 gaskets meet the Fugitive Emissions requirements, have been fire tested and approved according the requirements of the PVRC Fire Tightness Test (FITT) procedure and have been sealability tested per ROTT procedure. The PVRC design gasket constants 905 Gaskets with Flexible Graphite covering layers are as follows:
- Gb: 90 psi
- a: 0.547
- Gs: 0.388 psi
The standard material for the metal core is 316 Stainless Steel. Other alloys are available upon request.
Style 905 Corrugated Gaskets For Heat Exchangers
One of the most frequent uses of Style 905 Metalbest Gaskets are in Shell and Tube Heat Exchangers, due to their ability of to avoid mechanical shearing problems associated other gasket types in heavy thermal cycling applications. The standard core material is 316 Stainless Steel and the covering layer is Flexible Graphite. Other alloys are available upon request. The gasket thickness before seating is 0.080 in (2 mm) and the other dimensions and shapes are per application.
Kammprofile
Styles: 942, 946, 948

Description
Kammprofile Gaskets consist of a stainless metal core, with concentric grooves on either side. A sealing layer is applied to both faces and depending on the service the material for this layer can be Graphite, ePTFE, or a High Temperature Sheet material.

Style 942
Serrated Core without centering ring for male/female, tongue and groove and grooved flanges.

Style 948
Serrated Core with integral centering ring.

Style 946
Serrated Core with floating centering ring attached outside the sealing ring.

Style 946-Hot
Serrated Core with floating centering ring attached outside the sealing ring with Hi-Temp facing to protect the sealing material from oxidation.
Service Limits
Type | Description | Value |
---|---|---|
Temperature |
Maximum |
840 F (450 C) |
Operating Pressure |
3,700 psi (250 bar) |
Filler and Facing Materials

Description
In addition to the filler/facing materials offered in the metallic gasket product section, QUESTTM offers the following high temperature materials.
MICA
Phlogopite Hi-Temp grade to 1832°F (1000°C). Used in some hot gas applications, and as filler/facing for spiral wound and camprofile gaskets and as an oxidation barrier in combination with other sealing materials.
Ceramic Fiber
Used in some hot gases/ low pressure service. This material is also used as filler for metallic gaskets or in combination with other sealing materials. Temperature limit: 2000°F (1090°C).
XHR
Extreme heat resistance. Uses combination of mica barriers and APX2 to provide exceptional sealing ability to 1500°F (815°C).
PTFE
Polytetrafluoroethylene provides superior chemical resistance and great sealing ability. Typically rated to approximately 500°F (260°C).
Flexible Graphite
Provides soft conforming material in fire-safe design with excellent chemical resistance. Typically rated to 842°F (450°C).