FLANGES

Industrial Flanges for Reliable Piping Connections.

Avasi Energy supplies industrial pipe flanges in Sabah and Malaysia, supporting project, maintenance and operational requirements across oil & gas, petrochemical, energy and process industries.

Our sourcing scope covers standard and project-specific flange requirements, selected according to flange type, size, pressure class, material grade, bore, facing, dimensional standard, service conditions, inspection and documentation requirements.

Based in Kota Kinabalu, Sabah, Avasi Energy works with manufacturers and supply partners in Malaysia and internationally to coordinate flange requirements according to the customer’s specification and agreed supply scope.

A flange connection is more than two matching pieces of metal.

The integrity and compatibility of a flanged joint depend on several connected elements:

• Flange Type
• Size
• Pressure Class / Rating
• Material
• Facing
• Bore / Pipe Schedule
• Gasket
• Bolting
• Operating Conditions
• Applicable Standard

Selecting the correct flange therefore requires more than identifying the nominal pipe size.

Avasi Energy takes a requirement-first approach, reviewing the customer’s RFQ, material requisition, piping class, datasheet or project specification before coordinating suitable flange options.

Weld neck flanges feature a tapered hub and are butt welded directly to the pipe.

They are widely specified across process piping and industrial systems where the piping design requires a welded flange connection.

When ordering weld neck flanges, the bore and corresponding pipe wall thickness or schedule are important because they must align with the connecting pipe and project specification.

Requirements may involve:

• Raised Face — RF
• Ring Type Joint — RTJ
• Other project-specified facings

Material, class and dimensions are selected according to the applicable standard and service conditions.

Blind flanges are used to close the end of piping systems, equipment nozzles or other flanged connections where no central bore is required.

They may be used in systems requiring access for future modifications, inspection, maintenance or piping termination.

Selection depends on size, pressure class, material, facing, design standard and service conditions.

Slip-on flanges are positioned over the pipe and connected by welding according to the applicable piping design and fabrication requirements.

They are commonly specified in selected process and utility piping applications.

The correct flange must still align with the required size, bore, pressure class, material, facing and project specification.

Socket-weld flanges incorporate a socket into which the pipe is inserted before welding.

They are generally associated with smaller-bore piping systems where this type of connection is specified by the piping class or engineering requirement.

Selection must account for pipe size, pressure class, material, facing and applicable design standard.

Threaded flanges connect to compatible threaded piping and may be used in selected applications where the piping specification permits threaded construction.

Thread form, materials, pressure-temperature limitations and service conditions must follow the relevant project specification.

Lap joint flange arrangements are used together with compatible stub ends or lapped piping components.

Because the flange itself does not form the primary process-fluid contact surface in the same way as some other flange configurations, lap joint arrangements can provide practical benefits in selected piping systems.

Final configuration should follow the piping specification, material requirements and mating-component design.

Avasi Energy can also support selected project-specific flange requirements through suitable manufacturers and supply partners.

Depending on the specification, these may include:

1. Long Weld Neck Flanges

   • For equipment, vessel, nozzle or other project-specific connections where long-hub construction is required.

2. Orifice Flanges

   • Flange assemblies incorporating pressure differential connections for orifice-metering arrangements.
   • ASME B16.36 specifically covers orifice flanges and was updated in 2025.

3. Reducing Flanges

   • Where a flanged connection incorporates a change in nominal bore according to the engineering requirement.

4. Anchor or Special Forged Flanges

   • Project-specific configurations manufactured according to drawings, specifications or approved standards where required.

5. API Wellhead Flanges

   • Where specified for wellhead and tree equipment, requirements may involve flange connections governed by API Specification 6A and its applicable product requirements. API’s current 21st edition covers wellhead and tree equipment including flange-related components.

Availability of any special flange is subject to the applicable project specification and manufacturer capability.

Flange facing is not simply a surface-finish choice.

It forms part of the interface between the flange, gasket and mating connection.

Depending on the applicable standard and project requirement, flange facings may include:

1. Raised Face — RF

   • Commonly specified across many ASME flanged piping applications.

2. Ring Type Joint — RTJ

   • A machined ring groove arrangement used with the corresponding metallic ring gasket where specified.

3. Flat Face — FF

   • Specified for particular flange systems and equipment connections.

4. Other Facing Arrangements

   • Male-and-female or tongue-and-groove arrangements may also be required for selected project specifications.

The correct facing must align with the mating flange, gasket type and project design requirements.

ASME flange designations commonly include Classes such as:

• 150
• 300
• 400
• 600
• 900
• 1500
• 2500

depending on flange size and applicable standard.

However, a flange designated Class 300 does not simply mean a universal maximum pressure of 300 psi.

ASME B16.5 establishes pressure-temperature ratings based on factors including material grouping and temperature, in addition to dimensional and other requirements.

For that reason, the specified flange class must follow the piping design, material and operating conditions defined by the engineering specification.

1. ASME B16.5

   • ASME B16.5 covers pipe flanges and flanged fittings from NPS 1/2 through NPS 24, with class coverage depending on size. It addresses pressure-temperature ratings, materials, dimensions, tolerances, marking and testing.

2. ASME B16.47

   • For large-diameter steel flanges, ASME B16.47 covers NPS 26 through NPS 60 in rating Classes 75, 150, 300, 400, 600 and 900.
   • B16.47 also contains Series A and Series B flange dimensions.
   • This detail is particularly important because the two series are generally not interchangeable due to dimensional differences including bolt-circle arrangements.
   • For a B16.47 enquiry, the customer should therefore state:
     • Series A or Series B
     • rather than simply:
     • 30-inch Class 300 flange

3. ASME B16.36

   • Used for applicable orifice flange arrangements.

4. EN 1092-1

   • Where PN-designated European flange requirements apply, EN 1092-1 specifies steel flange requirements including type, facing, dimensions, materials and pressure-temperature ratings.

5. API Specification 6A

   • Where specified for wellhead and tree equipment.

Avasi Energy can support flange requirements in project-specified materials depending on application and manufacturer capability.

Carbon Steel

ASTM A105/A105M

A commonly specified forged carbon-steel material for pressure-system piping components in ambient and higher-temperature service.

Normalised condition may be required by the customer or project specification.

Low-Temperature Carbon Steel

ASTM A350/A350M, including specified LF grades such as LF2 where required.

ASTM A350 covers carbon and low-alloy steel forged components intended primarily for low-temperature service and requiring notch-toughness testing.

High-Yield Carbon / Alloy Steel

ASTM A694/A694M

Used for applicable high-strength transmission-service flange requirements, with grade selected according to project specifications.

Alloy Steel

Selected ASTM A182 grades may be specified for elevated-temperature or specialised process services.

Stainless Steel

Requirements may include project-specified 304/304L, 316/316L and other stainless grades covered by applicable material specifications.

Duplex & Super Duplex Stainless Steel

Requirements may include project-specified ASTM A182 grades such as F51, F53 or F55, depending on service conditions and engineering requirements.

ASTM A182/A182M covers forged or rolled alloy and stainless-steel piping components for pressure systems.

Special Alloys

Selected nickel and other corrosion-resistant alloy requirements may be sourced where specified and supported by suitable manufacturers.

Oil & gas applications may involve additional material and manufacturing requirements due to operating conditions.

Depending on the project specification, requirements may include:

• H₂S / Sour Service
• Low-Temperature Service
• High-Temperature Service
• Offshore / Marine Environment
• Corrosive Process Conditions
• Hardness Restrictions
• Additional NDE / NDT
• Impact Testing
• PMI Requirements
• Project-Specific Manufacturing Requirements

ISO 15156 currently governs material-selection principles for H₂S-containing oil and gas production environments, while a next edition is under development in 2026.

Avasi Energy coordinates these requirements according to the customer’s material requisition and project specification.

For critical piping systems, material traceability can be as important as flange dimensions.

Depending on the applicable specification and agreed supply scope, requirements may include verification of:

• Manufacturer
• Country of Origin, where required
• Heat Number
• Material Grade
• Flange Type
• Size
• Pressure Class
• Facing
• Standard
• Product Marking
• Material Certification
• Inspection Records

The product marking and documentation should remain traceable to the supplied material.

For oil & gas and project requirements, Avasi Energy can coordinate inspection, certification and documentation requirements according to manufacturer capability and the agreed supply scope.

These may include:

• Material Test Certificates — MTC / MTR
• EN 10204 3.1 / 3.2 Certification, where specified
• Chemical & Mechanical Test Results
• Dimensional Inspection
• Facing / Ring-Groove Inspection, where applicable
• Hardness Testing, where required
• Impact Testing, where required
• Positive Material Identification — PMI, where specified
• Non-Destructive Examination — NDE / NDT, where specified
• Third-Party Inspection — TPI
• Certificates of Conformity / Compliance
• Inspection & Test Plans — ITP
• Manufacturing Record Book / Data Book

The required inspection and documentation scope should be established during enquiry review rather than after manufacturing or delivery.

A flange rarely works alone.

The joint also depends on the compatible gasket and bolting arrangement.

That is why Avasi Energy’s piping-product portfolio also includes:

Gaskets

Metallic, semi-metallic and non-metallic sealing solutions according to flange design and project requirements.

Stud Bolts & Fasteners

Bolting requirements sourced according to flange class, materials and applicable project specifications.

For an accurate quotation, please provide the following information where available:

1. Flange Details
   • Flange Type
     • Weld Neck / Blind / Slip-On / Socket-Weld / Threaded / Lap Joint / Special
   • Size — NPS or DN
   • Pressure Class / PN Rating
   • Applicable Standard
   • Material Grade
   • Facing
     • RF / RTJ / FF / Other
   • Pipe Schedule or Bore Requirement
   • particularly for weld neck flanges
   • Quantity
2. Project Requirements
   • Service Conditions, where relevant
   • Sour-Service Requirement
   • Testing / Inspection Requirements
   • Documentation Requirements
   • Approved Manufacturer Requirements, if applicable
   • Country-of-Origin Requirements, if applicable
   • Required Delivery Date

Where available, attach:

• RFQ
• Material Requisition
• Piping Class
• Datasheet
• Drawing
• Project Specification

Example Flange Description

To make this section especially useful to procurement teams, show an example:

• Weld Neck Flange, NPS 10, Class 300, Sch 40 Bore, RF, ASME B16.5, ASTM A105, Qty 10

Example only — final description must follow the applicable project specification.

For large-diameter flanges, include the required ASME B16.47 Series A or Series B designation.

1. Review
   • We review the required pipe specification, grade, dimensions, quantity, testing and documentation requirements.
2. Source
   • Suitable manufacturers and supply sources are identified according to the stated requirement.
3. Technical Compliance
   • The proposed pipe is reviewed against the agreed technical and commercial scope.
4. Inspection & Documentation
   • Required certification, testing and inspection documentation is coordinated where included within the supply scope.
5. Delivery Coordination
   • Final documentation and delivery requirements are coordinated through order completion.

Avasi Energy is based in Kota Kinabalu, Sabah, supporting pipe and piping-material requirements for customers, projects and industrial operations in East Malaysia.

Our local presence is supported by access to manufacturers and supply partners in Malaysia and internationally, allowing us to coordinate requirements according to project specifications rather than restricting customers to a single source or product range.

This positioning is increasingly relevant as Sabah’s OGSE ecosystem develops. PETRONAS reported in February 2026 that contracts secured by recognised Sabah-based OGSE vendors had grown substantially since 2021.

We support requirements associated with:

• Oil & Gas
• Petrochemical & Process
• Energy
• Offshore & Onshore Projects
• Maintenance & Shutdowns
• Brownfield Modifications
• Replacement Requirements

Send Avasi Energy your RFQ, material requisition, piping class, datasheet or project specification.

Whether your requirement involves weld neck, blind, slip-on, socket-weld, threaded, large-diameter or specialised flanges, our team will review the scope and coordinate suitable sourcing options based on the stated technical, inspection, documentation and delivery requirements.