Lap Joint Flanges

Misalignment during assembly and frequent flange replacements can slow plant output and increase total system cost. Our Lap Joint Flanges allows fast rotation alignment while reducing weld stress on high-value piping.

Standard Specification

ASME B16.5, ASME B16.47 Series B, MSS SP-43, EN 1092-1

Pressure Rating

Class 150 to 900 (PN10 to PN64) [Lower than WN due to stub-end design]

Material

Carbon Steel (ASTM A105), Stainless Steel (A182 F304/F316), Aluminum (ASTM B247)

Nominal Size

½” to 60″ (DN15 to DN1500) [Commonly used in 2″-24″ (DN50-DN600) range]

Flange Type

Lap Joint (LJ) – Requires stub end for pipe connection

Product Description

Some flange types introduce fixed alignment or cause long-term corrosion at the joint. We use a loose ring design with dissimilar stub-end material, making the system easier to install and longer lasting.

Facing Type

Flat Face (FF) [Always matches stub end facing]

Dimensions

Loose ring design [Custom thickness available for alignment needs]

Bolt Circle Diameter

Matches standard flanges (ASME B16.5/EN 1092-1) [±1% tolerance for alignment]

Number & Size of Bolt Holes

4 to 48 holes (½” to 1″ bolts) [Matches standard flange patterns]

Surface Finish

Smooth machined (125-250 RA) [Contact surfaces precision-ground]

Corrosion Resistance

Often carbon steel flange with SS stub end [Dissimilar material combinations common]

Temperature Rating

-29°C to +400°C [Limited by stub end material]

Material Certification

MTR, EN 10204 3.1, PED 2014/68/EU [Separate certs for flange and stub end]

Gasket Compatibility

Full-face gaskets only [Matches stub end dimensions]

Coating/Plating

Often uncoated (flange rotates) [Stub end may have Xylan/PTFE coating]

Manufacturing Method

Plate-cut (SA516) or forged (A105) flange + forged/machined stub end

Technical Advantages

Misalignment tolerance and gasket wear are common issues in fixed flange systems. Our Lap Joint Flanges allows rotation, matching bolt patterns easily without stressing the pipe.

We supply carbon steel, stainless steel, and aluminum grades with surface finishes between 125–250 RA to match sealing demands. Loose ring design offers better fit-up during multi-bolt tightening cycles, especially in large-diameter or insulated systems.

Let's Get Started

Need reliable Flanges for your next project? Get in touch with us today, and we’ll help you find exactly what you need!

Industry Applications

Petrochemical Piping Systems

Used with corrosion-resistant stub ends to handle acidic or caustic fluid transport across storage and distribution lines.

Shipbuilding and Marine Systems

Allows quick disassembly during vessel maintenance; stub ends resist seawater corrosion in ballast and bilge systems.

Power Plant Heat Exchangers

Enables repeated alignment in thermal expansion areas; reduces stress on long run piping due to its rotating design.

Food Processing Lines

Works well with stainless stub ends where hygiene and regular cleaning cycles demand minimal flange face wear.

Water Treatment Units

Used in large diameter low-pressure lines with plastic or lined pipes; ideal for slip-on stub end connections.

Chemical Reactors

Ensures better gasket centering during shutdown maintenance; common in reactors with frequent flange breaks.

Consistent Fitment with Lower Maintenance Downtime

Our Lap Joint Flanges reduce site-time during bolt-up and disassembly tasks in rotating or low-pressure joints. Each flange matches EN or ASME bolt patterns with ±1% tolerance for field adjustability.

We offer both plate-cut and forged variants with optional coatings depending on operating media and temperature. With quick MTR access and EN 10204 3.1 documents, we help you speed up inspection and keep supply aligned with project timelines.

Having Doubts? Our FAQ

Check all our Frequently Asked Question

Does the Lap Joint Flange reduce total system cost over time?

Yes, the rotating feature lowers installation time and prevents flange replacement during maintenance. The stub end absorbs wear, so the flange can often be reused. This setup reduces long-term cost in multi-disassembly systems.

Can we use different materials for the flange and stub end?

Yes, buyers often choose carbon steel for the flange and stainless steel for the stub end. This pairing balances corrosion resistance and cost efficiency. It also supports differential expansion in temperature-sensitive lines.

Are Lap Joint Flanges suitable for systems under frequent realignment?

Yes, their loose ring design supports bolt pattern matching without rotating the pipe. This helps during equipment repositioning or repeated access. It keeps gasket sealing consistent while lowering mechanical stress.

How do these flanges perform in large diameter lines?

They work well in DN600 and above, where pipe movement and bolt alignment are harder to control. The rotatable ring simplifies the bolt hole alignment process. Stub ends also help reduce warping at larger flange faces.

What certifications are supplied with the flange and stub end?

We provide separate MTRs and EN 10204 3.1 certificates for each component. This supports full traceability for regulated sectors like oil and gas. You can match the stub end and flange grade to meet PED or ASME code checks.

Can Frigate support bulk orders with consistent flange quality across batches?

Yes, we maintain strict batch traceability with heat numbers and MTR linkage

CNC-controlled machining ensures uniform dimensions across large volumes

Dedicated QA checks for each production lot before dispatch

Suitable for EPC contractors and long-term supply agreements

What is Frigate’s typical lead time for Lap Joint Flanges and stub ends?

Standard sizes: ready dispatch or within 7–10 days

Custom dimensions/materials: typically 2–4 weeks depending on specs

Parallel production of flange + stub end reduces total delivery time

Priority manufacturing slots available for urgent shutdown projects

Can Frigate customize Lap Joint Flanges based on project drawings?

Yes, we manufacture as per client drawings, GA diagrams, or BOQs

Custom thickness, OD, drilling, and tolerances supported

Reverse engineering available for replacement of existing systems

Technical team validates drawings before production to avoid site issues

Does Frigate provide complete flange + stub end supply packages?

Yes, we supply matched flange and stub end sets for direct installation

Material compatibility ensured for corrosion and temperature conditions

Optional gasket and bolting kits can be included on request

Reduces multi-vendor dependency and simplifies procurement

How does Frigate ensure compliance with international project standards?

Manufacturing aligned with ASME, EN, MSS, and project-specific specs

Full documentation: MTRs, EN 10204 3.1, inspection reports included

Third-party inspection (TPI) support available (BV, SGS, TUV, etc.)

Pre-dispatch inspection and dimensional reports shared for approval

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LOCATIONS

Registered Office

10-A, First Floor, V.V Complex, Prakash Nagar, Thiruverumbur, Trichy-620013, Tamil Nadu, India.

Operations Office

9/1, Poonthottam Nagar, Ramanandha Nagar, Saravanampatti, Coimbatore-641035, Tamil Nadu, India. ㅤ

Other Locations

GENERAL ENQUIRIES

LOCATIONS

Registered Office

10-A, First Floor, V.V Complex, Prakash Nagar, Thiruverumbur, Trichy-620013, Tamil Nadu, India.

Components Built for Critical Performance

Engineered Products for Critical Applications

Lap Joint Flanges

Standard Specification

Pressure Rating

Material

Nominal Size

Flange Type

Product Description

Facing Type

Dimensions

Bolt Circle Diameter

Number & Size of Bolt Holes

Surface Finish

Corrosion Resistance

Temperature Rating

Material Certification

Gasket Compatibility

Coating/Plating

Manufacturing Method

Technical Advantages

Let's Get Started

Industry Applications

Consistent Fitment with Lower Maintenance Downtime

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Threaded Flanges

Plate Flanges

Having Doubts? Our FAQ

Get Clarity with Our Manufacturing Insights

We'd love to Manufacture for you!

LOCATIONS

Registered Office

Operations Office

Other Locations

GENERAL ENQUIRIES

LOCATIONS

Registered Office

Other Locations

GENERAL ENQUIRIES

Get Your Quote Now

Lap Joint Flanges

Get Latest Price

Lap Joint Flanges

Get Latest Price