Precision Fabrication for Oil & Gas, Petrochemical, Energy and Process Applications.

RESTRICTION ORIFICES

Restriction Orifices | Piping Products

Restriction Orifices. Machined to Specification.

Avasi Energy fabricates and supplies Restriction Orifices in Sabah and Malaysia according to customer-approved drawings, material specifications and project requirements.

Our scope focuses on precision machining, fabrication, material compliance, dimensional control, inspection and project documentation for Restriction Orifice plates and selected assemblies.

Requirements may include single-hole, multi-hole and multi-stage configurations, manufactured according to the dimensions, hole geometry, material, thickness, connection details and tolerances defined by the approved engineering design.

Send Your Drawing / RFQ

YOUR DESIGN. OUR FABRICATION.

Manufactured Against the Approved Requirement.

Restriction Orifices are used within piping systems to create a fixed restriction for pressure reduction or flow limitation. Specialist manufacturers design their geometry around process conditions such as flow, differential pressure, fluid properties, cavitation, critical flow and noise.

Avasi Energy’s standard scope begins after those engineering requirements have been defined.

We manufacture according to the customer-approved:

You define the engineered requirement. We manufacture it to specification.

WHAT IS A RESTRICTION ORIFICE?

A Fixed Restriction Within the Piping System.

A Restriction Orifice, commonly abbreviated as RO, is a fixed restriction installed within a piping system to create a defined pressure loss or limit flow.

Depending on the engineered design, it may use a single opening, multiple openings or multiple restriction stages. Specialist RO manufacturers currently offer all three configurations. Deltafluid

The required configuration is determined by the engineering design and process conditions.

Avasi Energy does not assume responsibility for defining the hydraulic design unless specialist engineering has been separately included within the agreed scope.

OUR RESTRICTION ORIFICE FABRICATION RANGE

From Simple Plates to Project-Specific Assemblies.

Single-Hole Restriction Orifices

Precision-Machined to the Approved Bore.

Single-hole Restriction Orifices incorporate one engineered opening within the restriction element.

Avasi Energy can machine and fabricate single-hole RO plates according to the customer’s approved drawing, including specified requirements for:

The bore size is manufactured to the dimensions stated on the approved drawing.

Send Single Hole RO RFQ

Multi-Hole Restriction Orifices

Complex Hole Patterns. Controlled Machining.

Multi-hole Restriction Orifices incorporate several engineered openings arranged according to the approved design.

The configuration may be used by the design engineer to address specific process-performance requirements. Specialist engineering companies, for example, use multi-hole arrangements in applications where noise reduction is required.

Avasi’s scope is to accurately reproduce the approved geometry, which may specify:

The engineering defines the pattern. Avasi manufactures the pattern.

Send Multi Hole RO RFQ

Multi-Stage Restriction Orifice Components & Assemblies

Fabricated According to the Approved Multi-Stage Design.

High differential-pressure duties may be engineered using multiple restriction stages rather than one plate. Specialist RO designers determine the number, geometry and spacing of stages from process data.

Where drawings and specifications are provided, Avasi Energy can support the fabrication of multi-stage Restriction Orifice components and selected assemblies, subject to the required construction and agreed manufacturing scope.

Requirements may involve:

All manufacturing is performed according to the approved drawing and fabrication specification.

Send Multi Stage RO RFQ

PRECISION MACHINING MATTERS.

Simple Appearance. Critical Dimensions.

A Restriction Orifice may appear to be a relatively simple machined component.

However, its engineered performance depends on the geometry defined by the designer.

Manufacturing therefore requires close attention to dimensions such as:

  1. Orifice Bore Diameter

    • The restriction opening must be machined according to the approved design dimension and tolerance.

  2. Hole Pattern

    • For multi-hole plates, quantity, spacing, position and individual bore size must follow the drawing.

  3. Plate Thickness

    • The finished thickness must comply with the approved manufacturing requirement.

  4. Concentricity & Position

    • The restriction geometry must be located according to drawing requirements.

  5. Edge Geometry

    • Square, sharp, rounded, bevelled or other edge configurations may be specified by the designer.

  6. Surface Finish

    • Machined surfaces may require project-specific finish requirements.

  7. Overall Dimensions

    • Outside diameter, handle/tab arrangement, connection interface and other dimensions must match the intended installation.

Correct engineering can only perform as intended when the manufactured geometry follows the approved design.

FABRICATED TO DRAWING.

No Assumptions. No Generic Bore Selection.

Avasi Energy does not select an orifice bore simply from:

4-inch Class 300 Restriction Orifice

The manufacturing requirement should identify the actual engineered dimensions.

This approach protects the integrity of both the engineering design and the supplied component.

Our fabrication is based on:

Drawing Approved. Dimensions Confirmed. Manufacturing Begins.

MATERIALS

Machined in Project-Specified Materials.

Depending on the application, customer specification and material availability, Avasi Energy can support Restriction Orifice requirements in materials including:

Stainless Steel

Common requirements may include:

Duplex Stainless Steel

For selected corrosive and offshore applications.

Super Duplex Stainless Steel

For demanding corrosion-resistant requirements where specified.

Carbon Steel

For applicable plate, body, spool or assembly components according to the approved design.

Nickel & Special Alloys

Materials such as nickel-based alloys may be sourced and machined where specified, subject to material availability and manufacturing capability.

Current international RO portfolios commonly include stainless steel, duplex, super duplex and selected nickel alloys for different process environments.

Final material selection remains the responsibility of the project/design specification.

PLATE & ASSEMBLY CONFIGURATIONS

Manufactured Around the Installation Design.

Restriction Orifices may be integrated into piping systems through different mechanical arrangements.

Depending on customer drawings, Avasi can support requirements such as:

  1. Between-Flange Restriction Plates
    • Machined restriction plates intended for installation between compatible flanges.
  2. Paddle-Type Restriction Plates
    • Plate configurations incorporating an identification or handling tab according to the customer’s drawing.
  3. Carrier / Holder Arrangements
    • Components designed for installation within customer-specified carriers or holders.
  4. Flanged Assemblies
    • Fabricated assemblies using specified flange connections.
  5. Butt-Weld / Spool Assemblies
    • Selected multi-stage or engineered configurations incorporated into fabricated spool arrangements, subject to Avasi’s agreed fabrication scope.
  6. Custom Components
    • Project-specific configurations manufactured according to approved engineering drawings.

RESTRICTION ORIFICE VS FLOW-MEASUREMENT ORIFICE PLATE

Similar Form. Different Function.

Restriction OrificeMeasurement Orifice Plate
Primary purposeCreate fixed pressure loss / limit flowMeasure flow using differential pressure
Design objectiveHydraulic restrictionMeasurement performance
Bore geometryDefined by RO engineering requirementDefined by measurement design
Avasi scopeFabricate to approved drawingFabricate to approved drawing where within product scope
Engineering responsibilityCustomer / appointed specialist unless separately agreedCustomer / appointed specialist unless separately agreed

International technical references clearly distinguish the pressure-reduction role of restriction orifices from measurement-oriented primary elements.

Similar appearance does not mean identical engineering purpose.

DESIGN BASIS & STANDARDS

The Drawing Defines the Manufactured Product.

There is no single universal standard that defines every Restriction Orifice design and sizing application.

Restriction Orifices are fabricated according to customer-approved drawings, project specifications, applicable material standards and relevant piping/interface standards.

Depending on the requirement, drawings may reference standards associated with:

INSPECTION & DIMENSIONAL CONTROL

Verify What Has Been Manufactured.

Depending on the agreed scope and project requirements, inspection may include verification of:

Manufactured to Drawing. Inspected Against Drawing.

MATERIAL TRACEABILITY

Know the Material Behind the Component.

Depending on project requirements, Avasi can maintain and coordinate traceability information including:

For critical project components, identification should remain traceable to the relevant manufacturing and material documentation.

TESTING & DOCUMENTATION

Documentation That Supports the Fabrication.

Depending on customer specifications and agreed scope, Avasi can coordinate documentation such as:

For fabricated pressure-containing assemblies, additional examination or pressure testing may be required according to the approved fabrication specification.

OPTIONAL ENGINEERING SUPPORT

Need Restriction Orifice Sizing or Hydraulic Calculation?

Avasi Energy’s standard scope is fabrication and machining according to customer-approved drawings and specifications.

Where the customer requires:

Avasi Energy can, upon request, coordinate specialist third-party engineering support as a separately agreed scope.

The engineering work may require dedicated calculation methodologies or specialist software, as demonstrated by established international RO engineering providers.

Clear Scope. Appropriate Expertise.

APPLICATIONS

Supporting Project-Specified Restriction Requirements.

Restriction Orifices are commonly engineered for applications involving pressure reduction or fixed flow limitation.

Applications may include:

Avasi’s responsibility is to fabricate the component according to the approved project design for the intended application.

TECHNICAL ENOUGH FOR ENGINEERING. CLEAR ENOUGH FOR PROCUREMENT.

Confidence Beyond the RO Fabrication.

Engineering teams need confidence that the manufactured geometry matches the approved design.

Procurement teams need clarity regarding:

Avasi Energy brings those requirements together through a fabrication-led supply approach.

Drawing Controlled. Material Traceable. Dimensions Verified.

WHAT TO SEND US FOR AN ACCURATE RFQ

Your Drawing Is the Best Starting Point.

Please provide, where available:

Where available, attach:

Send Your Drawing / RFQ

Example RFQ Description

Single-Hole Example

Restriction Orifice Plate, 4" Class 600, SS316L, Bore Ø22.50 mm, Plate Thickness 12 mm, dimensions and tolerances as per Drawing AV-RO-001 Rev.2, complete with MTC 3.1 and Dimensional Inspection Report.

Multi-Hole Example

Multi-Hole Restriction Orifice Plate, SS316L, 12 Holes X Ø8.0 mm, hole pattern, plate thickness and overall dimensions as per approved drawing, PMI and MTC 3.1 required.

Multi-Stage Example

Multi-Stage Restriction Orifice Components / Assembly, material and dimensions as per approved drawing and project specification, complete with specified inspection and manufacturing documentation.

Examples only. Final requirement must follow the customer’s approved drawing and specification.

FROM REQUIREMENT TO DELIVERY

A Focused Supply Process.

  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.

Specification Reviewed. Supply Coordinated. Documentation Aligned.

SUPPORTING SABAH’S INDUSTRIAL REQUIREMENTS

Based in Sabah. Connected Beyond Sabah.

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:

Local Presence. Wider Sourcing Capability.

COMPLETE THE FLANGED JOINT

Need the Matching Flanges / Gaskets / Stud Bolts?

Avasi Energy also supplies:

Pipe Fittings

Elbows, tees, reducers, caps, forged fittings and branch connections.

Flanges

Weld neck, blind, slip-on and other project-specified flange configurations.

Gaskets

Spiral wound, RTJ, kammprofile, non-metallic and selected industrial sealing solutions.

Pipes

Carbon steel, stainless steel, alloy and project-specific piping requirements.

Stud Bolts & FastenersLine Blanks

FREQUENTLY ASKED QUESTIONS

Does Avasi design and calculate Restriction Orifices?

Avasi Energy's standard scope is fabrication and machining according to customer-approved drawings and specifications.

If hydraulic sizing or specialist process engineering is required, third-party engineering support can be coordinated separately upon request.

Can Avasi machine single-hole Restriction Orifices?

Yes. Single-hole plates can be manufactured according to the bore diameter, plate thickness, material, overall dimensions and tolerances stated on the approved drawing.

Can Avasi fabricate multi-hole Restriction Orifices?

Yes, subject to drawing and manufacturing review. Hole quantity, diameter, pattern, spacing and other geometry must be defined by the approved design.

Can Avasi fabricate multi-stage Restriction Orifice assemblies?

Selected multi-stage components and assemblies can be fabricated according to approved engineering drawings and agreed manufacturing scope.

What information does Avasi need to quote a Restriction Orifice?

The most useful document is the manufacturing or approved engineering drawing. Material grade, dimensions, tolerances, quantity, inspection requirements and required documentation should also be provided.

Can Avasi supply stainless steel, duplex and super duplex Restriction Orifices?

Avasi can support project-specific material requirements including stainless steel, duplex, super duplex and selected special alloys, subject to material availability and manufacturing capability.

Can Avasi provide MTC and dimensional inspection reports?

Yes, material certification and dimensional inspection documentation can be coordinated according to the agreed project and supply requirements.

What if we only have process data and no manufacturing drawing?

Avasi's normal manufacturing scope requires defined dimensions or an approved drawing.

Where engineering is required to convert process information into an engineered Restriction Orifice design, Avasi can coordinate suitable third-party specialist support as a separate scope.

Have a Restriction Orifice Drawing?

Send Avasi Energy your RFQ, approved drawing, material requisition or project specification.

Whether your requirement involves a single-hole plate, multi-hole plate or multi-stage Restriction Orifice component, our team will review the manufacturing scope and coordinate fabrication according to the specified material, dimensions, inspection, documentation and delivery requirements.

Send Your Drawing / RFQ

AVASI ENERGY SDN BHD

Piping. Flow Control. Smarter Sourcing.