A Spiral wound gasket is a semi-metallic sealing component manufactured by winding a metallic strip and a soft filler material into alternating spiral layers. This construction combines the strength of metal with the compressibility of the filler, helping create a reliable seal between compatible flanged connections.
Spiral wound gaskets are widely used in oil and gas, petrochemical processing, refineries, power generation, chemical plants and other industrial systems where pressure, temperature fluctuations and process-fluid compatibility must be considered.
Selecting the right gasket involves more than matching its diameter to a pipe. The flange standard, nominal size, pressure class, facing, winding alloy, filler material, ring configuration and operating conditions all influence suitability.
This guide explains how spiral wound gaskets work, how their configurations differ, which materials are available, how dimensions and markings are specified, and what engineers should verify before ordering or installing a gasket.
How Does a Spiral Wound Gasket Work?
A spiral wound gasket seals a flanged joint by developing contact pressure between the gasket and the flange faces.
When the flange bolts are tightened, the metallic winding and filler are compressed. The filler conforms to suitable surface irregularities, while the resilient metal winding supports the sealing element and helps it accommodate changes in joint conditions.
During operation, pressure fluctuations, temperature changes and mechanical movement can affect the load acting on the joint. The gasket’s construction helps it maintain sealing contact when correctly selected and installed.
The inner and centering rings, when specified, provide additional support and positioning. Their requirements depend on the gasket configuration, flange arrangement and applicable standard.
The key factors behind effective sealing are:
- Correct gasket dimensions and configuration.
- Compatible winding and filler materials.
- Suitable flange-face condition and alignment.
- Adequate, evenly distributed bolt load.
- A controlled installation procedure.
- Operating conditions within the approved design limits.
A spiral wound gasket cannot compensate for damaged flange faces, incorrect assembly or unsuitable material selection. Reliable performance depends on the complete flange-joint system.
Spiral Wound Gasket Construction
A spiral wound gasket consists of a wound sealing element and may include an inner ring, an outer centering ring, or both. The exact construction depends on the intended application and specification.
1. Metallic Winding
The metallic winding is formed by wrapping a thin metal strip into a controlled spiral. It provides structural support and contributes to the gasket’s resilience under compression.
Common winding materials include SS304, SS316L and selected nickel-based alloys.
Material selection should consider:
- Process-fluid compatibility and corrosion risk.
- Operating and design temperatures.
- Pressure and mechanical requirements.
- Thermal cycling and service conditions.
- Compatibility with the specified filler and flange system.
The appropriate alloy should be selected from the actual process conditions rather than assuming that a more expensive alloy is always better.
2. Filler Material
The filler is positioned between the metallic windings and contributes to the gasket’s sealing performance. It helps conform to the flange surfaces under the required assembly load.
Common filler materials include flexible graphite, PTFE and selected high-temperature fillers such as mica-based or ceramic materials.
The filler should be evaluated for chemical compatibility, temperature limits, oxidation conditions and any contamination restrictions. The suitability of a filler depends on its specific grade and the complete operating environment.portant because different materials have significantly different chemical and temperature capabilities.
3. Inner Ring
An inner ring is a metallic ring positioned at the gasket’s inner diameter. It supports the sealing element and helps maintain the intended internal geometry.
Depending on the design, it can:
- Support the winding at the bore.
- Reduce the risk of inward deformation.
- Help limit exposure of the winding to the process flow.
- Provide additional dimensional stability.
- Support the specified gasket construction.
Inner-ring requirements should be checked against the applicable gasket standard, flange specification and service conditions. It should not be assumed that every high-pressure application automatically requires the same configuration. flange, size, pressure class and gasket specification rather than a blanket rule that every high-pressure gasket must have one.
4. Centering Ring
The outer centering ring helps position the gasket within the flange bolt circle and supports correct placement during assembly.
Depending on the design, it can:
- Improve concentric alignment.
- Assist handling and installation.
- Provide radial support.
- Help limit compression where the design specifies this function.
- Carry applicable identification markings.
A centering ring does not replace the need to verify the gasket dimensions or flange alignment.
Spiral Wound Gasket Types and Configurations
Spiral wound gasket configurations differ according to the presence or absence of inner and outer rings. Common designations include R, CG and CGI, although naming and availability should always be confirmed against the applicable specification.
| Configuration | Construction | Typical consideration |
|---|---|---|
| Style R | Spiral-wound sealing element without integral inner or centering rings | Used only where the specified flange arrangement and gasket requirements permit this construction |
| Style IR / inner-ring configuration | Sealing element with an inner ring | Provides internal support where required by the design |
| Style CG | Sealing element with an outer centering ring | Helps position the gasket and supports installation |
| Style CGI | Sealing element with inner and outer rings | Combines internal support with external centering |
These descriptions explain the general construction differences. Exact designations, dimensional requirements and permitted configurations must be verified against the applicable standard and manufacturer’s documentation. Do not assume that every supplier uses identical naming for every configuration.
Important: Spiral Wound Gaskets Are Not the Same as RTJ Gaskets
A common specification error is treating the “R” designation of a spiral wound gasket as a ring-joint gasket designation.
They are different gasket technologies.
Ring Type Joint (RTJ) gaskets are solid metallic rings with oval or octagonal cross-sections designed to fit RTJ grooves. API 6A, for example, contains requirements for ring gaskets used with wellhead and related equipment.
A spiral wound gasket is a semi-metallic wound gasket designed for the applicable flange configuration.
Therefore, do not select a spiral wound gasket merely because a flange is high pressure. First identify the actual flange facing and applicable standard.
Spiral Wound Gasket Filler Materials
Filler material affects sealing behaviour, chemical compatibility and temperature suitability. The correct choice depends on the process fluid, operating conditions and manufacturer’s technical limits.
| Filler | General Characteristics | Typical Applications |
|---|---|---|
| Flexible Graphite | Compressible and resilient, with broad industrial use | Commonly considered for steam, hydrocarbon and refinery service, subject to compatibility and oxidation limits |
| PTFE | Broad chemical resistance | Useful for many aggressive chemical services within its specified temperature and pressure limits |
| Mica-based filler | Available for selected elevated-temperature services | Suitability depends on the grade and application |
| Ceramic-based filler | Used in certain specialised high-temperature designs | Confirm the manufacturer’s temperature, chemical and sealing data |
Flexible Graphite
Flexible graphite is widely used in industrial spiral wound gaskets because of its compressibility and recovery characteristics. It is commonly considered for steam, hydrocarbon and other process applications.
However, graphite is not suitable for every chemical environment. Oxidising conditions, process chemistry, operating temperature and any purity requirements should be reviewed before specification.
PTFE
PTFE offers resistance to many chemicals and is frequently considered for applications where chemical compatibility is a priority.
Its performance depends on the specific grade, temperature, pressure, joint design and compression conditions. PTFE should not be selected based on chemical resistance alone; the complete gasket construction must be suitable for the application.
Mica and Ceramic Fillers
Mica-based and ceramic-based fillers are used in selected high-temperature applications. Their suitability varies according to material grade, construction and service environment.
Before selecting either filler, verify its operating limits, chemical compatibility and manufacturer’s technical documentation. A maximum temperature figure alone does not establish suitability for a pressurised flange joint.
Do not choose a filler solely from a maximum temperature number. Process chemistry, pressure, oxidation environment and manufacturer-specific data must also be considered.
Spiral Wound Gasket Winding Materials
The winding material must provide suitable mechanical strength and resistance to the process environment.
| Winding Material | General Characteristics | Typical Selection Consideration |
|---|---|---|
| SS304 | General-purpose austenitic stainless steel | Suitable for selected industrial environments |
| SS304L | Low-carbon stainless steel | Consider where low-carbon construction is specified |
| SS316 | Stainless steel with molybdenum addition | Offers improved resistance in many corrosive environments compared with SS304 |
| SS316L | Low-carbon SS316 | Used in selected elevated-temperature services |
| SS321 | Stabilized stainless steel | Used in selected elevated-temperature services |
| SS347 | Stabilized stainless steel | Considered for suitable elevated-temperature applications |
| Inconel 600/625 | Nickel-based alloys | Specialized high-temperature or corrosive service |
| Monel 400 | Nickel-copper alloy | Considered for compatible marine and chemical services |
| Hastelloy alloys | Nickel-based corrosion-resistant alloys | Used in selected aggressive chemical environments |
These descriptions are general guidance, not a material compatibility guarantee. Alloy grades have different properties, and their suitability depends on the exact chemical composition, temperature, concentration and operating conditions.
SS316L is not automatically the best choice for every application, and nickel-based alloys should not be selected without confirming the relevant service requirements.
Spiral Wound Gasket Material Selection
A suitable spiral wound gasket requires a coordinated selection of the flange, winding, filler and ring configuration.
| Selection Factor | What to Verify |
|---|---|
| Flange Standard | ASME, EN, JIS or another applicable system |
| Normal Size | NPS / DN |
| Operating pressure | Class or PN, as applicable |
| Flange facing | RF, FF or another specified facing |
| Winding material | Stainless steel or a suitable alloy |
| Filler | Graphite, PTFE or another compatible material |
| Temperature | Normal and design operating conditions |
| Media | Fluid composition and compatibility |
| Standard | Applicable dimensional and material requirements |
A practical selection process starts with the flange specification, then checks the process conditions and the materials required to maintain sealing performance.
Avoid choosing a gasket solely because it matches the nominal pipe size or because a similar gasket has been used in another application. Differences in flange facing, pressure class, temperature or process media can change the requirements.
Standards for Spiral Wound Gaskets
Gasket standards define important requirements for construction, dimensions, materials, markings and compatibility. The applicable standard depends on the flange system and equipment specification.
ASME B16.20
ASME B16.20 covers metallic gaskets for pipe flanges, including applicable spiral-wound gasket requirements. It addresses matters such as dimensions, materials, tolerances and markings within its scope.
It should be used with the relevant flange standard and project specification. Always verify the applicable edition and the gasket configuration required for the particular joint.
ASME B16.5
ASME B16.5 covers pipe flanges and flanged fittings within its stated size and pressure-class scope. For a gasket used with a compatible flange, the dimensions must correspond to the applicable flange size, class and facing.
The flange standard and gasket standard perform different functions and should be checked together.
ASME B16.47
ASME B16.47 covers large-diameter steel flanges, including Series A and Series B. When specifying a gasket for these flange systems, confirm the applicable series and all relevant dimensional requirements.
Do not assume that matching nominal pipe size alone is enough to establish gasket compatibility.
EN 1514-2
EN 1514-2 specifies dimensions and marking requirements for spiral wound gaskets used with relevant steel flange systems within its scope. Confirm the applicable edition, DN size, PN designation and compatible flange standard before ordering.
European flange requirements should not be treated as interchangeable with ASME dimensions.
JIS B 2404
JIS B 2404 specifies types and dimensions of gaskets used with the applicable JIS flange systems within its scope. Check the relevant edition and associated flange standard when selecting a gasket for Japanese-standard equipment.
Material suitability and operating limits must also be verified independently against the applicable specification.
API 6A
API Specification 6A applies to wellhead and Christmas tree equipment within its scope and includes requirements for relevant equipment and sealing components. It should not be treated as a universal dimensional standard for all spiral wound gaskets.
For a particular wellhead or related application, follow the equipment specification and the applicable requirements for the sealing component.
Standards Selection Summary
| Application / Flange System | Relevant Standard to Verify |
|---|---|
| Applicable ASME pipe flanges | ASME B16.20 with the relevant flange standard, such as ASME B16.5 |
| Large-diameter ASME flanges | ASME B16.20 with the applicable ASME B16.47 series requirements |
| Relevant European PN flange systems | EN 1514-2 and the applicable EN flange standard |
| Applicable JIS flange systems | JIS B 2404 and the relevant JIS flange standard |
| Wellhead and Christmas tree equipment | Applicable API 6A requirements for the specified equipment and sealing component |
Always establish the flange standard before finalising the gasket specification. Confirm all dimensions and materials against the current applicable edition rather than relying on an unsourced online chart.
ASME B16.20 Spiral Wound Gasket Color Coding
ASME B16.20 includes standardized material identification through color coding and abbreviations.
For spiral-wound gasket color coding , the winding material is identified by a continuous color around the outer edge of the centering ring, while filler identification uses intermittent stripes. ASME B16.20 specifies four filler stripes at approximately 90-degree intervals for NPS 1½ and larger, with smaller gaskets having at least two stripes.
Selected examples include:
| Metallic Winding | ASME B16.20 Color Code |
|---|---|
| Carbon Steel | Silver |
| Type 304 SS | Yellow |
| Type 316L SS | Green |
| Type 317L SS | Maroon |
| Type 321 SS | Turquoise |
| Type 347 SS | Blue |
| Monel 400 | Orange |
| Nickel 200 | Red |
| Titanium Grade 2/7 | Purple |
| Inconel 600 | Gold |
| Inconel 625 | Gold |
Selected filler markings include:
| Filler | Color stripe |
|---|---|
| Flexible Graphite | Gray |
| PTFE | White |
| Ceramic | Light Green |
| Vermiculite / specified mica materials | Refer to applicable standard marking |
The current ASME table contains a considerably larger material list than the simplified charts commonly published online. Therefore, do not rely on a short color chart as a substitute for the current ASME B16.20 marking requirements.
For critical service, verify the gasket marking, purchase specification, material documentation and applicable certificate rather than identifying the material from color alone.
Spiral Wound Gasket Dimensions
Depending on the design, important dimensions include:
- Inside and outside diameters of the sealing element.
- Outside diameter of the centering ring.
- Inside diameter of the inner ring.
- Gasket thickness.
- Ring dimensions and required clearances.
- Dimensional relationships to the flange bore and bolt circle.
Use the dimensional tables applicable to the specified flange and gasket standard. A dimension chart for one flange system should not be applied automatically to another.d inner-ring use.
Information Required for Ordering
Avoid ordering a gasket using only a description such as “6-inch Class 300.” That information may be insufficient to establish the correct dimensions and configuration.
A more complete specification should include:
Nominal size + flange standard + pressure class + flange facing + gasket configuration + winding material + filler material + ring requirements.
For example, an enquiry might specify an NPS 6 gasket for an ASME B16.5 Class 300 raised-face flange, with a CGI configuration, SS316L winding and flexible graphite filler.
This is an illustrative specification format, not confirmation of the correct gasket dimensions for a particular flange. The final configuration must be checked against the applicable standard, project requirements and operating conditions.
Spiral Wound Gasket Pressure and Temperature Selection
There is no single pressure or temperature rating that applies to every spiral wound gasket. The permissible operating conditions depend on the gasket materials, construction, flange design and complete joint assembly.
Review the following factors:
- Applicable flange pressure-temperature rating.
- Flange material and pressure class.
- Gasket winding and filler materials.
- Operating and design temperatures.
- Operating and design pressures.
- Process-fluid compatibility.
- Flange condition and bolt-load requirements.
- Relevant design codes and manufacturer data.
The pressure class assigned to a flange does not mean that the assembled joint can operate at the same pressure under every temperature condition.
Similarly, a filler’s stated maximum temperature does not establish the complete gasket’s operating limit. Oxidising conditions, chemical exposure, flange loading and joint design may impose additional restrictions.
For engineering applications, verify the applicable flange pressure-temperature tables and obtain product-specific technical information. Do not rely on generic pressure figures or temperature charts without checking their scope and assumptions.
Spiral Wound Gasket Installation Best Practices
Correct installation is essential for achieving reliable sealing. Even a correctly selected gasket can leak if the flange faces are damaged, the gasket is misplaced or the bolting procedure is unsuitable.
1. Inspect the Flange
Before installation, inspect both flange faces for corrosion, pitting, radial scratches, distortion, residue and other damage that may interfere with sealing.
Confirm that the flange alignment and surface condition meet the applicable joint requirements. Correct any unacceptable condition before proceeding.
2. Verify the Gasket
Check the gasket’s size, configuration, winding material, filler, ring arrangement and identification markings against the approved specification.
Inspect it for visible damage, distortion or contamination. Use the relevant documentation where traceability or material certification is required.
3. Position the Gasket
Position the gasket carefully and ensure that it is correctly aligned with the flange arrangement. Use the centering ring where provided.
Do not force a gasket into position or use a gasket with incompatible dimensions to compensate for flange misalignment.
4. Check Bolting
Inspect the studs, bolts, nuts and threads for damage, corrosion and other unacceptable conditions. Confirm that the specified bolting materials and lubrication method are suitable for the joint.
Lubrication changes friction and can significantly affect the bolt load achieved at a given torque.
5. Tighten in a Controlled Pattern
Use the approved tightening sequence and progressively apply the required bolt load in multiple passes. A suitable cross-pattern sequence helps distribute load more evenly around the flange.
The exact procedure should follow the applicable assembly instructions and engineering requirements.
6. Use a Defined Assembly Procedure
Do not rely on a single generic torque value for every spiral wound gasket. The appropriate tightening method and target load depend on the joint design, bolting, lubrication, flange characteristics and gasket requirements.
ASME PCC-1 provides guidance for pressure-boundary bolted flange joint assembly. Use the applicable engineering procedure to establish the target bolt load, tightening sequence and verification requirements.
Never assume that increasing torque will necessarily stop leakage. Excessive or uneven loading can damage the gasket or flange and create additional joint problems.
Common Spiral Wound Gasket Failure Causes
While spiral wound gaskets are renowned for their high resilience and ability to withstand severe pressure fluctuations, joint integrity depends on proper selection, handling, and installation. In many industrial processing units, recurring flange leaks are mistakenly attributed to component failure rather than systemic assembly issues. If you are evaluating different semi-metallic sealing options, understanding the key operational differences in our complete guide to spiral wound gaskets can help prevent premature joint failure. Below are the most frequent causes of spiral wound gasket breakdown and their direct impact on flange performance:
| Failure Cause | Possible Effect |
|---|---|
| Incorrect gasket dimensions | Poor seating or interference with the flange bore |
| Incompatible filler material | Chemical degradation or reduced sealing performance |
| Unsuitable winding material | Corrosion or material degradation |
| Insufficient bolt load | Inadequate sealing contact |
| Excessive bolt load | Gasket damage or flange distortion |
| Uneven bolt loading | Localized leakage |
| Damaged flange face | Leakage path across the sealing surface |
| Incorrect gasket configuration | Poor positioning or inadequate support |
| Thermal cycling | Changes in joint load |
| Reusing a compressed gasket | Unreliable sealing during reassembly |
| Inconsistent lubrication | Variation in the achieved bolt load |
| Flange misalignment | Uneven gasket compression |
When a joint leaks repeatedly, investigate the gasket specification, flange condition, bolting, assembly procedure and operating history. Corrective action should address the underlying cause rather than simply replacing the gasket with a different material.
How to Choose the Right Spiral Wound Gasket ?
Use this six-step process before Choosing the Right Spiral Wound Gasket or placing an order.
Step 1: Identify the Flange
Record the flange standard, nominal size, pressure class or PN designation, facing and flange material.
These details establish the dimensional and compatibility requirements for the gasket.
Step 2: Identify the Service
Document the process media, chemical composition, normal and design temperatures, normal and design pressures, and any relevant vacuum or cycling conditions.
Include unusual operating conditions that may affect material selection.
Step 3: Select the Filler
Choose a filler based on chemical compatibility, temperature suitability, required sealing behaviour and the manufacturer’s technical data.
Do not select graphite, PTFE or another filler based on one property alone.
Step 4: Select the Winding
Choose a suitable stainless steel or alloy based on the process environment, corrosion risks, temperature and mechanical requirements.
Confirm the exact grade required by the specification.
Step 5: Determine the Gasket Configuration
Establish whether the application requires a basic sealing element, an outer centering ring, an inner ring or a combined configuration.
Verify the configuration against the applicable standard and flange requirements instead of relying on a general rule based only on pressure class.
Step 6: Verify Dimensions
Check the final dimensions against the relevant gasket standard and flange specification. Confirm the ring arrangement, facing compatibility and all project-specific requirements before manufacture or installation.
Spiral Wound Gasket Applications
Spiral wound gaskets are used in industrial systems where the flange joint requires a compatible semi-metallic sealing solution. The correct construction depends on the equipment, process conditions and applicable specification.
Oil and Gas
Applications may include process piping, gas-processing systems, refinery equipment, compressors, pumps and other compatible flanged connections.
Material and configuration choices should reflect the actual process fluid, pressure, temperature and equipment requirements.
Petrochemical and Chemical Processing
Spiral wound gaskets may be used in compatible reactors, heat exchangers, distillation equipment, process piping, pumps and valves.
Chemical compatibility is particularly important when selecting the winding and filler materials.
Power Generation
Applications can include suitable steam systems, heat exchangers, turbine-related equipment and other industrial flange connections.
Elevated-temperature service requires careful review of the filler, winding, flange design and assembly procedure.
Marine and Offshore
Spiral wound gaskets may be specified for compatible marine piping, utility systems, pumps, valves and offshore process equipment.
Corrosion resistance and the actual service environment should guide material selection.
Water and Industrial Processing
Suitable applications may include water treatment, desalination, industrial process lines and pumping systems.
The selected gasket must remain compatible with the fluid, flange arrangement and intended operating conditions.
Spiral Wound Gasket Specification Checklist
Before requesting a quotation, prepare the available technical information. A complete specification helps reduce errors in gasket selection and dimensional verification.
| Specification | Information to provide |
|---|---|
| Gasket type | Required configuration or drawing reference |
| Size | NPS/DN |
| Flange standard | ASME B16.5, B16.47, EN, JIS, etc. |
| Pressure class | Class 150/300/600/etc. or PN |
| Facing | RF, FF, tongue-and-groove, etc. |
| Winding | SS304, SS316L, Inconel, Monel, etc. |
| Filler | Required/not required according to specification |
| Centering ring | Required/not required |
| Temperature | Operating/design temperature |
| Pressure | Operating/design pressure |
| Media | Process fluid |
| Quantity | Required quantity |
| Drawing | Required for custom or non-standard dimensions where applicable |
If some information is unavailable, share the equipment drawing, flange specification or existing gasket identification for technical review. Do not guess missing dimensions or materials.
Why Proper Spiral Wound Gasket Selection Matters ?
Correct gasket selection supports reliable flange-joint performance and helps reduce avoidable maintenance.
A suitable specification and installation procedure can help:
- Reduce the risk of flange leakage.
- Limit unplanned maintenance and downtime.
- Improve consistency during joint assembly.
- Reduce material incompatibility risks.
- Support dependable operation within design limits.
- Simplify identification and replacement during maintenance.
These benefits depend on the complete joint system. Gasket construction, flange condition, bolting, installation and operating conditions all influence performance.
Why Choose Asian Sealing for Spiral Wound Gaskets?
Asian Sealing Products supplies spiral wound gasket solutions for industrial applications, with selection based on the required dimensions, materials, configuration and applicable standards.
When evaluating a gasket for your application, the technical requirements should be established before the final product is specified.
- Configurations: Requirements can be assessed for spiral wound constructions with suitable inner and centering rings.
- Material options: Winding and filler combinations can be evaluated according to the requested specification and application.
- Standards: Applicable dimensional and material requirements should be confirmed against the relevant ASME, EN, JIS or other specified standard.
- Pressure classes and sizes: Availability should be verified for the required flange size, pressure designation and configuration.
- Custom requirements: Drawings and dimensional information can be reviewed for application-specific requirements.
- Technical documentation: Request the relevant product data, dimensional details and material documentation for the specified gasket.
For a quotation or technical enquiry, provide the flange standard, size, pressure class, facing, operating temperature, pressure, process media and required materials. These details help establish which gasket construction should be evaluated.
Conclusion
Selecting a spiral wound gasket involves more than matching the gasket diameter to a pipe. The flange standard, pressure designation, facing, winding material, filler, ring configuration and operating conditions must be considered together.
For an ASME application, identify the applicable gasket standard and compatible flange standard. For EN or JIS flange systems, use the relevant requirements for that system rather than transferring dimensions from another standard.
Material compatibility and installation are equally important. Confirm the specified operating limits, inspect the flange faces, use an approved bolting procedure and verify the final gasket dimensions before installation.
Asian Sealing Products can evaluate spiral wound gasket requirements using the available flange details, material specification, drawing and operating conditions. Providing complete technical information helps reduce specification errors and supports a more suitable product selection.
Frequently Asked Questions
Dimensions depend on the flange standard, nominal size, pressure designation, facing and gasket configuration. Depending on the design, relevant measurements include the sealing element’s inside and outside diameters, centering ring dimensions, inner ring dimensions and thickness. Verify the final dimensions against the applicable standard and flange specification.
Spiral wound gaskets are used in compatible flanged connections across oil and gas, refineries, petrochemical processing, chemical plants, power generation, marine systems and other industrial applications. Their suitability depends on the actual operating conditions and specified gasket construction.
Style CG generally refers to a spiral wound sealing element with a centering ring, while Style CGI generally includes both a centering ring and an inner ring. The correct configuration depends on the applicable standard, flange arrangement, gasket specification and service conditions. Verify the required designation before ordering.
No. The Style R designation used for certain spiral wound gasket configurations should not be confused with an RTJ gasket. A spiral wound gasket uses metal winding and filler, whereas an RTJ gasket is a solid metallic ring designed for a compatible ring-joint flange groove. They are different sealing systems.
There is no universally best filler. Flexible graphite is commonly considered for many steam and hydrocarbon applications, while PTFE may be suitable for a wide range of chemically aggressive services. The correct choice depends on process compatibility, temperature, pressure, gasket construction and manufacturer data.
Not in every application. SS316L offers improved resistance in many corrosive environments, but the appropriate winding material depends on the process fluid, temperature and material requirements. Confirm the exact alloy grade against the operating conditions and specification.
ASME B16.20 covers applicable metallic gasket requirements for ASME flange systems. The relevant flange standard, such as ASME B16.5 or ASME B16.47, must also be identified. Other flange systems may require different gasket standards.
Yes. The standard includes marking requirements within its scope. Check the applicable edition and the specified material and configuration rather than relying on a simplified colour chart.
No. Inner-ring requirements depend on the applicable standard, gasket configuration, flange arrangement and service conditions. Confirm the required construction against the project specification and relevant technical documentation.
A compressed spiral wound gasket should generally be replaced when a flange joint is dismantled. Reuse can compromise sealing reliability because the gasket has already undergone compression and may have been affected by service conditions or handling.
Common causes include incorrect dimensions, unsuitable materials, insufficient or uneven bolt load, damaged flange faces, flange misalignment, thermal cycling and improper installation. Repeated leakage requires an assessment of the complete flange-joint system.
There is no single pressure or temperature rating applicable to all spiral wound gaskets. Suitability depends on the gasket construction, winding and filler materials, flange pressure-temperature rating, process media and joint assembly. Verify the complete operating envelope against the relevant engineering requirements and product data.
ASME B16.20 covers applicable metallic gasket requirements, including dimensions, materials, tolerances and markings. ASME B16.5 covers pipe flanges and flanged fittings within its scope. Both may need to be considered when specifying a compatible gasket for an ASME flange.
EN 1514-2 specifies dimensional and marking requirements for spiral wound gaskets used with applicable steel flange systems within its scope. Confirm the relevant edition, flange standard, DN size and PN designation before selecting the gasket.
Custom requirements can be evaluated based on the available drawings, flange dimensions, material specifications and operating conditions. Provide the relevant technical information so the required configuration and dimensions can be assessed before manufacture.
Inspect the flange faces, verify the gasket specification, position the gasket correctly and tighten the bolting using an approved assembly procedure. The target bolt load and tightening method must suit the complete joint. Follow applicable engineering guidance, such as ASME PCC-1 where relevant, rather than using a generic torque value for every application.
