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FLANGES & FITTINGS MANUFACTURING · STEEL PIPE SUPPLYinfo@lkpiping.com

LEKE PIPING / PRODUCTS

Lap Joint Flanges

Lap joint flanges pair with matching stub ends. Specify both components and whether the stub end is included.

Lap joint flanges stacked with open bores visible

PRODUCT DETAILS

Specify the connection completely.

We can also make custom sizes, thicknesses and other dimensions to your drawing. Send your specifications with your RFQ so we can confirm the details.

ParameterDetails to confirm
AssemblyBacking flange and matching stub end
CompatibilityProvide flange bore and corner radius, stub end type, lap dimensions and matching pipe wall
MaterialsSpecify the material standard, grade and certificate requirements for each component
StandardIdentify the flange and stub end standards, editions and assembly drawing revision

Product dimensions, material grades and documentation are confirmed against your enquiry and applicable project requirements.

Primary dimensional reference: ASME B16.5 (NPS 1/2–24 where the type is covered); specify the matching stub end. Confirm the product type, edition and applicable size before order.

DIMENSIONAL REFERENCE

Lap Joint Flange dimensional drawing.

Use the section view to identify the dimensions to confirm in your enquiry.

Lap Joint Flange dimensional reference
Lap Joint Flange
View full-size drawing ↗

Reading this drawing

D
Flange outside diameter
t
Flange thickness indicated by the drawing
X
Hub outside diameter indicated by the drawing
B₃
Lap-joint bore dimension indicated by the drawing
R
Internal corner radius indicated by the drawing
T₃
Overall length through the hub indicated by the drawing

Symbols describe this supplied drawing. Confirm their correspondence with the selected standard and dimension table; notation may differ.

Review the backing flange and stub end as an assembly. Confirm lap geometry, gasket-contact surface and mating connection against the approved drawing; do not apply a generic facing-height value to the assembly.

SELECTION & ENQUIRY

The details that make the difference.

01

Define the assembly

State whether you need the backing flange, the stub end or both. List the quantity of each component separately.

02

Confirm compatibility

Provide the stub end drawing, including lap diameter, thickness, radius and length. Check compatibility with the backing flange and connected pipe before ordering.

03

Specify materials separately

List both material grades and required inspection records. Any difference in materials must meet the approved project specification and service requirements.

TECHNICAL REFERENCES

Check dimensions before your RFQ.

ASME B16.5 / B16.47

Flange dimensions and connection references

Check that the reference covers the required lap joint flange and matching stub end. A large-diameter flange reference alone does not establish assembly compatibility; use the specified standards and approved drawing.

Open technical resources →

DIMENSIONAL REFERENCES

Product reference dimensions.

Reference data retained from the existing product page. Check the stated standard, edition, units and the approved project specification.

Open dimensional reference tables

Standard & Custom Flange Solutions

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Third-party Inspection

Expert Technical Support

Material Selection Advice

Custom Dimensions Available

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Response within 24 hours

Legacy lap joint flange dimensional reference; check the stated units and specification

ANSI B16.5 CLASS 150 FORGED Lap Joint FLANGES dimensions specification

Nominal Pipe SizeOutside Diam.DDiam. at Base of Hub X O.D. of Raised Face G Thickness t Lap Joint B3Lap Joint T3Diam. of Hub at Bevel ARadius of Fillet R
1/28930.2 35.1 11.2 22.9 15.7 21.3 3.0
3/49938.1 42.9 12.7 28.2 15.7 26.7 3.0
110849.3 50.8 14.2 35.1 17.5 33.5 3.0
1 1/411758.7 63.5 15.7 43.7 20.6 42.2 4.8
1 1/212765.0 73.2 17.5 50.0 22.4 48.3 6.4
215277.7 91.9 19.1 62.5 25.4 60.5 7.9
2 1/217890.4 104.6 22.4 75.4 28.4 73.2 7.9
3191108.0 127.0 23.9 91.4 30.2 88.9 9.7
3 1/2216122.2 139.7 23.9 104.1 31.8 101.6 9.7
4229134.9 157.2 23.9 116.8 33.3 114.3 11.2
5254163.6 185.7 23.9 144.5 36.6 141.2 11.2
6279192.0 215.9 25.4 171.5 39.6 168.4 12.7
8343246.1 269.7 28.4 222.3 44.5 219.2 12.7
10406304.8 323.9 30.2 277.4 49.3 273.1 12.7
12483365.3 381.0 31.8 328.2 55.6 323.9 12.7
14533400.1 412.8 35.1 360.2 79.2 355.6 12.7
16597457.2 469.9 36.6 411.2 87.4 406.4 12.7
18635505.0 533.4 39.6 462.3 96.8 457.2 12.7
20699558.8 584.2 42.9 514.4 103.1 508.0 12.7
24813663.4 692.2 47.8 616.0 111.3 609.6 12.7
» All dimensions are in mm.
» These flanges will be furnished with a 1/16″ raised face unless otherwise specified.
» Standard Bore will be furnished unless otherwise specified.

ASME B16.5
Welding Neck Flanges
ASME B16.47 Series B
Welding Neck Flanges
ASME B16.47 Series A
Welding Neck Flanges
Class 150Class 75
Class 300Class 150Class 150
Class 600Class 300Class 300
Class 900Class 400Class 400
Class 1500Class 600Class 600
Class 2500Class 900Class 900

COMMON QUESTIONS

Before you send the enquiry.

Does the quotation include the stub end?

Specify whether you need the backing flange only or the complete flange-and-stub-end assembly.

How should quantities be listed for a lap joint assembly?

List the required number of loose flanges and stub ends separately, or explicitly define the contents of each set. Use matching item references to avoid an incomplete assembly.

Which stub-end dimensions should be checked?

Provide the stub-end drawing and check the neck, lap and contact dimensions against the loose flange. Confirm that the two components are intended to work together.

Must the loose flange and stub end use the same material?

Specify the material for each part separately. Material selection must follow the project design, including which component contacts the process fluid.

What helps prevent a mismatched lap joint assembly?

Send both component drawings, quantities and the mating connection requirements. Do not select a loose flange solely from its outside diameter or photograph.

SEND YOUR REQUIREMENT

From your specification
to a clearer quotation.

Email your item list with quantities, destination and required delivery date. Flag any open points.

USEFUL TO INCLUDE
  • Flange size, standard and class
  • Stub end type and dimensions
  • Flange and stub end materials
  • Quantity, drawing and documentation

The quotation will confirm supply scope, required documents and delivery terms.