Lap Joint Flanges

What are Lap Joint Flanges?

Lap Joint Flanges are two-piece pipe connection components consisting of a flange and a stub end. The flange slides freely over the pipe and is positioned behind the stub end, which is welded to the pipe. This design allows for easy alignment and rotation of the flange, making it ideal for piping systems that require frequent disassembly or realignment.

Asiad Steel Industries is a leading manufacturer and exporter of high-quality Lap Joint Flanges in stainless steel, carbon steel, and special alloys for diverse industries worldwide.

Key Features

Strong &
Reliable Connection

Durable
Construction

Easy Installation
& Removal

Wide
Compatibility

Corrosion
Resistant

Specifications

Specification Category Parameter / Feature Details / Options
Size Range Nominal Pipe Size (NPS) ½” to 48” (DN15 – DN1200)
Pressure Ratings ANSI / ASME Class
Class 150, 300, 600, 900, 1500, 2500

PN Ratings
PN6, PN10, PN16, PN25, PN40, PN64

Fitting Types Lap Joint Flanges Standard Lap Joint, Slip-On Lap Joint, Weld Neck Lap Joint
Material Options Stainless Steel SS 304, SS 304L, SS 316, SS 316L, SS 321
Carbon Steel ASTM A105, ASTM A350 LF2
Alloy / Superalloy Alloy Steel (A182 F1, F5, F9, F11, F22, F91), Inconel 600/625/825
Duplex & Super Duplex Duplex 2205, Super Duplex 2507
Other Materials Monel 400/K500, Nickel 200/201, Titanium (Grade 2, Grade 5)
Standards & Certifications ASME / ANSI ASME B16.5, ASME B16.47 (Series A & B)
ASTM ASTM A182, ASTM A105
European Standards DIN 2501, EN 1092-1
Certifications ISO 9001, PED 2014/68/EU, NACE MR0175, IBR Approved
Design Features Wall Thickness As per ASME B16.5, customized options
Face Type Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)
End Connections Socket Weld Ends, Beveled Ends, Plain Ends
Tolerance As per ASME/ANSI standards
Coating & Surface Finish Anti-Corrosion Coating Rust Preventive Oil, Black Oxide, Hot-Dip Galvanized
Optional Coatings Epoxy, PTFE, Polyurethane
Surface Finish Machined, Pickled, Polished, Passivated
Testing & Inspection Pressure Testing Hydrostatic, Pneumatic
Non-Destructive Testing Radiography (RT), Ultrasonic (UT), Magnetic Particle (MPI), Dye Penetrant (DPT)
Destructive Testing Tensile, Hardness, Impact

Dimensions

NPS (in) Class OD (mm) Thickness T (mm) BCD (mm) No. of Bolts Bolt Size RF Dia (mm)
½ 150 92 16 62 4 ½”-13 UNC 70
½ 300 102 19 68 4 ½”-13 UNC 76
½ 600 114 22 79 4 ½”-13 UNC 89
½ 900 127 25 92 4 ½”-13 UNC 102
½ 1500 140 32 105 4 ½”-13 UNC 114
½ 2500 152 38 117 4 ½”-13 UNC 127
¾ 150 102 16 70 4 ½”-13 UNC 79
¾ 300 114 19 76 4 ½”-13 UNC 89
¾ 600 127 22 89 4 ½”-13 UNC 102
¾ 900 140 25 102 4 ½”-13 UNC 114
¾ 1500 152 32 114 4 ½”-13 UNC 127
¾ 2500 165 38 127 4 ½”-13 UNC 140
1 150 114 19 79 4 ½”-13 UNC 89
1 300 127 22 89 4 ½”-13 UNC 102
1 600 140 25 102 4 ½”-13 UNC 114
1 900 152 28 114 4 ½”-13 UNC 127
1 1500 165 32 127 4 ½”-13 UNC 140
1 2500 178 38 140 4 ½”-13 UNC 152
150 152 22 102 4 ⅝”-11 UNC 108
300 165 25 114 4 ⅝”-11 UNC 127
600 178 28 127 4 ⅝”-11 UNC 146
900 190 32 133 4 ⅝”-11 UNC 165
1500 203 38 146 4 ⅝”-11 UNC 178
2500 216 41 159 4 ⅝”-11 UNC 190
2 150 165 22 114 4 ⅝”-11 UNC 127
2 300 178 25 127 4 ⅝”-11 UNC 146
2 600 190 28 133 4 ⅝”-11 UNC 165
2 900 203 32 146 4 ⅝”-11 UNC 178
2 1500 216 38 159 4 ⅝”-11 UNC 190
2 2500 229 41 171 4 ⅝”-11 UNC 203
150 190 25 133 4 ⅝”-11 UNC 146
300 203 28 146 4 ⅝”-11 UNC 165
600 216 32 159 4 ⅝”-11 UNC 178
900 229 38 171 4 ⅝”-11 UNC 190
1500 241 41 184 4 ⅝”-11 UNC 203
2500 254 44 196 4 ⅝”-11 UNC 216
3 150 216 25 156 4 ⅝”-11 UNC 165
3 300 229 28 159 4 ⅝”-11 UNC 178
3 600 241 32 171 4 ⅝”-11 UNC 190
3 900 254 38 184 4 ⅝”-11 UNC 203
3 1500 267 41 196 4 ⅝”-11 UNC 216
3 2500 279 44 209 4 ⅝”-11 UNC 229

Mechanical Properties

Property Value Unit / Standard
Tensile Strength 485 – 750 MPa (Carbon Steel, Stainless Steel, Alloy Steel)
Yield Strength 170 – 450 MPa
Hardness 120 – 200 HB (Brinell)
Elongation ≥ 20 – 30 %
Density 7.8 – 8.0 g/cm³
Impact Toughness ≥ 27 – 70 J (Charpy, grade-dependent)
Modulus of Elasticity (E) ~200 GPa
Fatigue Strength 200 – 400 MPa
Corrosion Resistance Good to Excellent (SS > CS > Alloy Steel)
Thermal Conductivity 15 – 50 W/m·K
Coefficient of Thermal Expansion 11 – 17 ×10⁻⁶ /°C
Yield Ratio (YS/UTS) 0.40 – 0.65
Poisson’s Ratio 0.27 – 0.30
Brinell Hardness Range 120 – 200 HB
Surface Finish Serrated / Stock / Smooth finish per ASME B16.5
Welding Type Socket weld or butt weld to pipe (as per application)
Operating Temperature Range -46 to 600 °C (material-dependent)
Pressure Rating Class 150, 300, 600, 900, 1500 ASME B16.5 Standards

Chemical Composition

Element SS 304 (%) SS 304L (%) SS 316 (%) SS 316L (%)
Carbon (C) ≤ 0.08 ≤ 0.03 ≤ 0.08 ≤ 0.03
Manganese (Mn) ≤ 2.00 ≤ 2.00 ≤ 2.00 ≤ 2.00
Silicon (Si) ≤ 1.00 ≤ 1.00 ≤ 1.00 ≤ 1.00
Phosphorus (P) ≤ 0.045 ≤ 0.045 ≤ 0.045 ≤ 0.045
Sulfur (S) ≤ 0.030 ≤ 0.030 ≤ 0.030 ≤ 0.030
Chromium (Cr) 18.0 – 20.0 18.0 – 20.0 16.0 – 18.0 16.0 – 18.0
Nickel (Ni) 8.0 – 10.5 8.0 – 12.0 10.0 – 14.0 10.0 – 14.0
Molybdenum (Mo) 2.0 – 3.0 2.0 – 3.0
Iron (Fe) Balance Balance Balance Balance

Applications of Lap Joint Flanges

Construction &
Infrastructure

Power Generation &
Energy Sector

Manufacturing &
Fabrication

Medical & Laboratory
Equipment

Electrical &
Electronics Assembly

Oil, Gas & Petrochemical
Installations

Do you have questions?

Why choose a Lap Joint Flange over other types?
Can Lap Joint Flanges handle high-pressure environments?
Are Lap Joint Flanges reusable?
Do you offer stub ends along with the flanges?

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