Lap Joint Flange
At Parmar TechnoForge Pvt. Ltd., we are a trusted manufacturer and exporter of Lap Joint Flanges, designed to provide efficient and cost-effective solutions in piping systems that require frequent dismantling for inspection, maintenance, or cleaning.
A Lap Joint Flange (LJ Flange) works in combination with a Stub End, allowing the flange to rotate freely around the pipe. This unique design minimizes bolt hole alignment issues and reduces stress on the piping system. Our Lap Joint Flanges are manufactured as per international standards such as ASME B16.5, ASME B16.47, MSS-SP-44, and API 605, ensuring precision, durability, and superior corrosion resistance.
These flanges are ideal for low-pressure and non-critical applications, particularly in systems where corrosion resistance is required inside the pipe but cost-effective materials can be used externally.
| Types | WITH REST FACE / FLAT FACE |
|---|---|
| Size | 1/2" NB TO 48" NB |
| Class | 150#, 300#, 400#, 600#, 900#, 1500# & 2500# |
| Stainless Steel | ASTM A182 F304/304L/316/316L/321/Etc. |
| Carbon Steel | ASTM A105/A105N/A350 LF2, Etc. |
| Duplex / Super Duplex | ASTM A182 F51/F53/F55/UNS S31803/S32750/S32760 |
| Alloy Steel | ASTM A182 F5/F9/F11/F22/Etc. |
| Others Non-Ferrous / Exotic Grade | Monel, Inconel, Hastelloy, Copper Nickel (CuNi10Fe1,6Mn), 70/30 Copper Nickel (CuNi30Fe), DOW Copper, Aluminium, Etc. |
| Standards & Specifications | ASME-B16.5, ASME-B16.47, API-605, MSS-SP-44, DIN/BS, NACE-MR0175/MR0103, PED / IBR Certification (where applicable) |
Dimensions of CL. 150 Flanges
| Nominal Pipe Size | Outside Diameter of Flange O | Thickness of Flange tf | Thickness Lap Joint tf | Diameter of Hub X | Diameter Beginning of Chamfer Welding Neck Ah | Threaded Slip-on Socket Welding Y | Lapped Y | Welding Neck Y | Thread Length Threaded Min. T | Slip-on Socket Welding Min. B | Lapped Min. B | Welding Neck/Socket Welding B | Corner Bore Radius of Lapped Flange and Pipe r | Depth of Socket D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.5 | 0.38 | 0.44 | 1.19 | 0.84 | 0.56 | 0.62 | 1.81 | 0.62 | 0.88 | 0.9 | 0.62 | 0.12 | 0.38 |
| 3/4 | 3.88 | 0.44 | 0.5 | 1.5 | 1.05 | 0.56 | 0.62 | 2 | 0.62 | 1.09 | 1.11 | 0.82 | 0.12 | 0.44 |
| 1 | 4.25 | 0.5 | 0.56 | 1.94 | 1.32 | 0.62 | 0.69 | 2.12 | 0.69 | 1.36 | 1.38 | 1.05 | 0.12 | 0.5 |
| 1 1/4 | 4.62 | 0.56 | 0.62 | 2.31 | 1.66 | 0.75 | 0.81 | 2.19 | 0.81 | 1.7 | 1.72 | 1.38 | 0.19 | 0.56 |
| 1 1/2 | 5 | 0.62 | 0.69 | 2.56 | 1.9 | 0.81 | 0.88 | 2.38 | 0.88 | 1.95 | 1.97 | 1.61 | 0.25 | 0.62 |
| 2 | 6 | 0.69 | 0.75 | 3.06 | 2.38 | 0.94 | 1 | 2.44 | 1 | 2.44 | 2.46 | 2.07 | 0.31 | 0.69 |
| 2 1/2 | 7 | 0.81 | 0.88 | 3.56 | 2.88 | 1.06 | 1.12 | 2.69 | 1.12 | 2.94 | 2.97 | 2.47 | 0.31 | 0.75 |
| 3 | 7.5 | 0.88 | 0.94 | 4.25 | 3.5 | 1.12 | 1.19 | 2.69 | 1.19 | 3.57 | 3.6 | 3.07 | 0.38 | ... |
| 3 1/2 | 8.5 | 0.88 | 0.94 | 4.81 | 4 | 1.19 | 1.25 | 2.75 | 1.25 | 4.07 | 4.1 | 3.55 | 0.38 | ... |
| 4 | 9 | 0.88 | 0.94 | 5.31 | 4.5 | 1.25 | 1.31 | 2.94 | 1.31 | 4.57 | 4.6 | 4.03 | 0.44 | ... |
| 5 | 10 | 0.88 | 0.94 | 6.44 | 5.56 | 1.38 | 1.44 | 3.44 | 1.44 | 5.66 | 5.69 | 5.05 | 0.44 | ... |
| 6 | 11 | 0.94 | 1 | 7.56 | 6.63 | 1.5 | 1.56 | 3.44 | 1.56 | 6.72 | 6.75 | 6.07 | 0.5 | ... |
| 8 | 13.5 | 1.06 | 1.12 | 9.69 | 8.63 | 1.69 | 1.75 | 3.94 | 1.75 | 8.72 | 8.75 | 7.98 | 0.5 | ... |
| 10 | 16 | 1.12 | 1.19 | 12 | 10.75 | 1.88 | 1.94 | 3.94 | 1.94 | 10.88 | 10.92 | 10.02 | 0.5 | ... |
| 12 | 19 | 1.19 | 1.25 | 14.38 | 12.75 | 2.12 | 2.19 | 4.44 | 2.19 | 12.88 | 12.92 | 12 | 0.5 | ... |
| 14 | 21 | 1.31 | 1.38 | 15.75 | 14 | 2.19 | 3.12 | 4.94 | 2.25 | 14.14 | 14.18 | 0.5 | ... | |
| 16 | 23.5 | 1.38 | 1.44 | 18 | 16 | 2.44 | 3.44 | 4.94 | 2.5 | 16.16 | 16.19 | 0.5 | ... | |
| 18 | 25 | 1.5 | 1.56 | 19.88 | 18 | 2.62 | 3.81 | 5.44 | 2.69 | 18.18 | 18.2 | 0.5 | ... | |
| 20 | 27.5 | 1.62 | 1.69 | 22 | 20 | 2.81 | 4.06 | 5.62 | 2.88 | 20.2 | 20.25 | 0.5 | ... | |
| 24 | 32 | 1.81 | 1.88 | 26.12 | 24 | 3.19 | 4.38 | 5.94 | 3.25 | 24.25 | 24.25 | 0.5 | ... |
Note: (1) This dimension is for the large end of the hub, which may be straight or tapered. Taper shall not exceed 7° on threaded, slip-on, and lapped flanges.
Dimensions of CL. 300 Flanges
| DIMENSIONS OF CL. 300 FLANGES | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal Pipe Size | Outside Diameter of Flange (O) | Thickness of Flange Min. (tf) | Thickness Lap Joint Min. (t) | Diameter of Hub (X) | Diameter Beginning of Chamfer Welding Neck (Ah) | Threaded / Slip-on / Socket Welding (Y) | Lapped (Y) | Welding Neck (Y) | Thread Length Threaded Min. (T) | Slip-on Socket Welding Min. (B) | Lapped Min. (B) | Welding Neck / Socket Welding (B) | Corner Bore Radius of Flange and Pipe (r) | Counter-bore Threaded Flange Min. (Q) | Depth of Socket (D) |
| 1/2 | 3.75 | 0.5 | 0.56 | 1.5 | 0.84 | 0.81 | 0.88 | 2 | 0.62 | 0.88 | 0.9 | 0.62 | 0.12 | 0.93 | 0.38 |
| 3/4 | 4.62 | 0.56 | 0.62 | 1.88 | 1.05 | 0.94 | 1 | 2.19 | 0.62 | 1.09 | 1.11 | 0.82 | 0.12 | 1.14 | 0.44 |
| 1 | 4.88 | 0.62 | 0.69 | 2.12 | 1.32 | 1 | 1.06 | 2.38 | 0.69 | 1.36 | 1.38 | 1.05 | 0.12 | 1.41 | 1/2 |
| 1 1/4 | 5.25 | 0.69 | 0.75 | 2.5 | 1.66 | 1 | 1.06 | 2.5 | 0.81 | 1.7 | 1.72 | 1.38 | 0.19 | 1.75 | 5/9 |
| 1 1/2 | 6.12 | 0.75 | 0.81 | 2.75 | 1.9 | 1.13 | 1.19 | 2.63 | 0.88 | 1.95 | 1.97 | 1.61 | 0.25 | 1.98 | 5/8 |
| 2 | 6.5 | 0.81 | 0.88 | 3.31 | 2.38 | 1.25 | 1.31 | 2.69 | 1.12 | 2.44 | 2.46 | 2.07 | 0.31 | 2.5 | 2/3 |
| 2 1/2 | 7.5 | 0.94 | 1 | 3.94 | 2.88 | 1.44 | 1.5 | 2.94 | 1.25 | 2.94 | 2.97 | 2.47 | 0.31 | 3 | 3/4 |
| 3 | 8.25 | 1.06 | 1.12 | 4.62 | 3.5 | 1.63 | 1.69 | 3.06 | 1.25 | 3.57 | 3.6 | 3.07 | 0.38 | 3.63 | 4/5 |
| 3 1/2 | 9 | 1.12 | 1.19 | 5.25 | 4 | 1.69 | 1.75 | 3.13 | 1.44 | 4.07 | 4.1 | 3.55 | 0.38 | 4.13 | – |
| 4 | 10 | 1.19 | 1.25 | 5.75 | 4.5 | 1.82 | 1.88 | 3.32 | 1.44 | 4.57 | 4.6 | 4.03 | 0.44 | 4.63 | – |
| 5 | 11 | 1.31 | 1.38 | 7 | 5.56 | 1.94 | 2 | 3.82 | 1.69 | 5.66 | 5.69 | 5.05 | 0.44 | 5.69 | – |
| 6 | 12.5 | 1.38 | 1.44 | 8.12 | 6.63 | 2 | 2.06 | 3.82 | 1.81 | 6.72 | 6.75 | 6.07 | 0.5 | 6.75 | – |
| 8 | 15 | 1.56 | 1.62 | 10.25 | 8.63 | 2.38 | 2.44 | 4.32 | 2 | 8.72 | 8.75 | 7.98 | 0.5 | 8.75 | – |
| 10 | 17.5 | 1.81 | 1.88 | 12.62 | 10.75 | 2.56 | 3.75 | 4.56 | 2.19 | 10.88 | 10.92 | 10.02 | 0.5 | 10.88 | – |
| 12 | 20.5 | 1.94 | 2 | 14.75 | 12.75 | 2.82 | 4 | 5.06 | 2.38 | 12.88 | 12.92 | 12 | 0.5 | 12.94 | – |
| 14 | 23 | 2.06 | 2.12 | 16.75 | 14 | 2.94 | 4.38 | 5.56 | 2.5 | 14.14 | 14.18 | – | 0.5 | 14.19 | – |
| 16 | 25.5 | 2.19 | 2.25 | 19 | 16 | 3.19 | 4.75 | 5.69 | 2.69 | 16.16 | 16.19 | – | 0.5 | 16.19 | – |
| 18 | 28 | 2.31 | 2.38 | 21 | 18 | 3.44 | 5.12 | 6.19 | 2.75 | 18.18 | 18.2 | – | 0.5 | 18.19 | – |
| 20 | 30.5 | 2.44 | 2.5 | 23.12 | 20 | 3.69 | 5.5 | 6.32 | 2.88 | 20.2 | 20.25 | – | 0.5 | 20.19 | – |
| 24 | 36 | 2.69 | 2.75 | 27.62 | 24 | 4.13 | 6 | 6.56 | 3.25 | 24.25 | 24.25 | – | 0.5 | 24.19 | – |
Note: (1) This dimension is for the large end of the hub, which may be straight or tapered. Taper shall not exceed 7° on threaded, slip-on, and lapped flanges.
Dimensions of CL. 600 Flanges
| DIMENSIONS OF CL. 600 FLANGES | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal Pipe Size | Outside Diameter of Flange (O) | Thickness of Flange Min. (t) | Diameter of Hub (X) | Hub Dia. Beginning of Chamfer Welding Neck (A) | Length Through Hub Threaded/Slip-on (Y) | Length Through Hub Lapped (Y) | Length Through Hub Welding Neck (Y) | Thread Length Min. (T) | Bore Slip-on Min. (B) | Bore Lapped Min. (B) | Bore Welding Neck (B) | Corner Radius (r) | Counter-bore Threaded Flange (Q) | Depth of Socket (D) |
| 1/2 | 3.75 | 0.56 | 1.50 | 0.84 | 0.88 | 0.88 | 2.06 | 0.62 | 0.88 | 0.90 | To Be Specified By Purchaser | 0.12 | 0.93 | 0.38 |
| 3/4 | 4.62 | 0.62 | 1.88 | 1.05 | 1.00 | 1.00 | 2.25 | 0.62 | 1.09 | 1.11 | 0.12 | 1.14 | 0.44 | |
| 1 | 4.88 | 0.69 | 2.12 | 1.32 | 1.06 | 1.06 | 2.44 | 0.69 | 1.36 | 1.38 | 0.12 | 1.41 | 0.50 | |
| 1 1/4 | 5.25 | 0.81 | 2.50 | 1.66 | 1.12 | 1.12 | 2.62 | 0.81 | 1.70 | 1.72 | 0.19 | 1.75 | 0.56 | |
| 1 1/2 | 6.12 | 0.88 | 2.75 | 1.90 | 1.25 | 1.25 | 2.75 | 0.88 | 1.95 | 1.97 | 0.25 | 1.99 | 0.62 | |
| 2 | 6.50 | 1.00 | 3.31 | 2.38 | 1.44 | 1.44 | 2.88 | 1.12 | 2.44 | 2.46 | 0.31 | 2.50 | 0.69 | |
| 2 1/2 | 7.50 | 1.12 | 3.94 | 2.88 | 1.62 | 1.62 | 3.12 | 1.25 | 2.94 | 2.97 | 0.31 | 3.00 | 0.75 | |
| 3 | 8.25 | 1.25 | 4.62 | 3.50 | 1.81 | 1.81 | 3.25 | 1.38 | 3.57 | 3.60 | 0.38 | 3.63 | 0.81 | |
| 3 1/2 | 9.00 | 1.38 | 5.25 | 4.00 | 1.94 | 1.94 | 3.38 | 1.56 | 4.07 | 4.10 | 0.38 | 4.13 | ||
| 4 | 10.75 | 1.50 | 6.00 | 4.50 | 2.12 | 2.12 | 4.00 | 1.62 | 4.57 | 4.60 | 0.44 | 4.63 | ||
| 5 | 13.00 | 1.75 | 7.44 | 5.56 | 2.38 | 2.38 | 4.50 | 1.88 | 5.66 | 5.69 | 0.44 | 5.69 | ||
| 6 | 14.00 | 1.88 | 8.75 | 6.63 | 2.62 | 2.62 | 4.62 | 2.00 | 6.72 | 6.75 | 0.50 | 6.75 | ||
| 8 | 16.50 | 2.19 | 10.75 | 8.63 | 3.00 | 3.00 | 5.25 | 2.25 | 8.72 | 8.75 | 0.50 | 8.75 | ||
| 10 | 20.00 | 2.50 | 13.50 | 10.75 | 3.38 | 4.38 | 6.00 | 2.56 | 10.88 | 10.92 | 0.50 | 10.88 | ||
| 12 | 22.00 | 2.62 | 15.75 | 12.75 | 3.62 | 4.62 | 6.12 | 2.75 | 12.88 | 12.92 | 0.50 | 12.94 | ||
| 14 | 23.75 | 2.75 | 17.00 | 14.00 | 3.69 | 5.00 | 6.50 | 2.88 | 14.14 | 14.18 | 0.50 | 14.19 | ||
| 16 | 27.00 | 3.00 | 19.50 | 16.00 | 4.19 | 5.50 | 7.00 | 3.06 | 16.16 | 16.19 | 0.50 | 16.19 | ||
| 18 | 29.25 | 3.25 | 21.50 | 18.00 | 4.62 | 6.00 | 7.25 | 3.12 | 18.18 | 18.20 | 0.50 | 18.19 | ||
| 20 | 32.00 | 3.50 | 24.00 | 20.00 | 5.00 | 6.50 | 7.50 | 3.25 | 20.20 | 20.25 | 0.50 | 20.19 | ||
| 24 | 37.00 | 4.00 | 28.25 | 24.00 | 5.50 | 7.25 | 8.00 | 3.62 | 24.25 | 24.25 | 0.50 | 24.19 | ||
Note: (1) This dimension is for the large end of the hub, which may be straight or tapered. Taper shall not exceed 7° on threaded, slip-on, and lapped flanges.