On January 15, 2025, we received an inquiry from a long-standing Vietnamese client regarding ASME B16.5 weld neck flanges, ASME B16.20 metal wound gaskets, bolts, nuts, and other flange pipe fittings. After confirming specifications, materials, quantities, and packaging requirements, we promptly provided a quotation based on the client’s provided list. As this client is a long-term partner, we are thoroughly familiar with their application conditions and procurement practices, enabling smooth communication throughout the process. The customer remained highly satisfied with our pricing, delivery schedule, and quality standards, placing an order one week later.
Procurement List
| Description | Material | Unit | Quantity |
| FLANGE 1″ LWN RF L=157 300# ASME B16.5 | SA-350 LF2 CL.1 | PCS | 2 |
| FLANGE 1″ LWN RF L=159 300# ASME B16.5 | SA-350 LF2 CL.1 | PCS | 1 |
| FLANGE 2″ LWN RF L=154 300# ASME B16.5 | SA-350 LF2 CL.1 | PCS | 1 |
| SPIRAL WOUND GASKET 1″ 300# ASME B16.20 | 316L+316L/FG+316L | PCS | 2 |
| SPIRAL WOUND GASKET 10″ 150# ASME B16.20 | 316L+316L/FG+316L | PCS | 1 |
| SPIRAL WOUND GASKET 16″ 150# ASME B16.20 | 316L+316L/FG+316L | PCS | 4 |
| HEX. NUT 1″-UNC | SA-194 2H | PCS | 128 |
| HEX. NUT 1.1/2″-8UN | SA-194 2H | PCS | 240 |
| HEX. NUT 1.1/4″-8UN | SA-194 2H | PCS | 96 |
| HEX. NUT 3/4″-UNC | SA-194 2H | PCS | 16 |
| HEX. NUT 5/8″-UNC | SA-194 2H | PCS | 64 |
| HEX. BOLT M22*100MM | SA-193 B7 | PCS | 2 |
| STUD BOLT 1″-UNC L=145MM | SA-193 B7 | PCS | 32 |
| STUD BOLT 1″-UNC L=155MM | SA-193 B7 | PCS | 32 |
| STUD BOLT 1.1/2″-8UN L=270MM | SA-193 B7 | PCS | 56 |
Inspection photos

Weld Neck Flanges feature a long tapered hub that transfers stress smoothly to the pipe, providing high strength and fatigue resistance under high pressure and temperature. The butt-weld connection reduces turbulence and stress concentration, ensuring reliable sealing in critical pipeline systems.
| Item | Details |
| Product Type | Lap Joint Flange (LWN RF) |
| Size & Pressure | 1″, 2″,300# |
| Production Standard | ASME B16.5 |
| Material Standard | ASTM A350 LF2 CL.1 |
| Material Composition | C ≤ 0.30%, Mn 0.60-1.35%, Si 0.15-0.30% |
Spiral Wound Gaskets consist of alternating layers of metal strips and flexible filler, such as graphite or PTFE. The structure maintains elasticity, compensates for flange surface irregularities, and withstands thermal cycling, offering stable and reliable sealing in high-pressure and high-temperature pipelines.
| Item | Details |
| Product Type | Spiral Wound Gasket |
| Size & Pressure | 1″, 10″, 16″,150#& 300# |
| Production Standard | ASME B16.20 |
| Material Standard | 316L / Flexible Graphite / 316L |
| Material Composition | C ≤ 0.03%, Cr 16.0-18.0%, Ni 10.0-14.0%, Mo 2.0-3.0% |
Bolts and nuts provide the clamping force needed for flange connections. When tightened to the specified torque, bolts generate tension that compresses the gasket, forming a leak-proof joint. The material of bolts and nuts must match the flange pressure rating and operating conditions to ensure strength, corrosion resistance, and long-term stability.
| Item | Details |
| Product Type | Stud Bolt / Hex Bolt |
| Size | 1″-UNC, 1.1/2″-8UN, M22 |
| Material Standard | ASTM A193 |
| Material Composition | C 0.37-0.49%, Cr 0.80-1.10%, Mo 0.15-0.25% |
| Item | Details |
| Product Type | Stud Bolt / Hex Bolt |
| Size | 1″-UNC, 1.1/2″-8UN, M22 |
| Material Standard | ASTM A193 |
| Material Composition | C 0.37-0.49%, Cr 0.80-1.10%, Mo 0.15-0.25% |

| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 95.20 | 15.70 | 14.20 | 52.30 | 21.30 | 38.10 | 35.00 | 4 | 15.70 | 66.55 | 0.75 |
| 3/4 | 26.70 | 117.3 | 20.80 | 15.70 | 57.15 | 26.70 | 47.70 | 42.90 | 4 | 19.00 | 82.50 | 1.26 |
| 1 | 33.40 | 123.9 | 26.70 | 17.50 | 62.00 | 33.50 | 53.80 | 50.80 | 4 | 19.00 | 88.90 | 1.52 |
| 1 1/4 | 42.20 | 133.3 | 35.10 | 19.00 | 65.00 | 42.20 | 63.50 | 63.50 | 4 | 19.00 | 98.50 | 2.03 |
| 1 1/2 | 48.30 | 155.4 | 40.90 | 20.60 | 68.30 | 48.30 | 69.85 | 73. 15 | 4 | 22.30 | 114.3 | 2.89 |
| 2 | 60.30 | 165. 1 | 52.60 | 22.30 | 69.85 | 60.45 | 84.00 | 91.90 | 8 | 19.00 | 127.0 | 3.4 |
| 2 1/2 | 73.00 | 190.5 | 62.70 | 25.40 | 76.20 | 73.15 | 100.0 | 104.6 | 8 | 22.30 | 149.3 | 5.17 |
| 3 | 88.90 | 209.5 | 78.00 | 28.40 | 79.25 | 88.90 | 117.3 | 127.0 | 8 | 22.30 | 168.1 | 6.93 |
| 3 1/2 | 101.6 | 228.6 | 90.20 | 30.20 | 81.00 | 101.6 | 133.3 | 139.7 | 8 | 22.30 | 184.1 | 8.67 |
| 4 | 114.3 | 254.0 | 102.4 | 31.70 | 85.80 | 114.3 | 146.0 | 157.2 | 8 | 22.30 | 200.1 | 11.2 |
| 5 | 141.3 | 279.4 | 128.3 | 35.00 | 98.50 | 141.2 | 177.8 | 185.7 | 8 | 22.30 | 234.9 | 15.1 |
| 6 | 168.3 | 317.5 | 154.2 | 36.50 | 98.50 | 168.4 | 206.2 | 215.9 | 12 | 22.30 | 269.7 | 19.1 |
| 8 | 219.1 | 381.0 | 202.7 | 41.10 | 111.2 | 219.2 | 260.3 | 269.7 | 12 | 25.40 | 330.2 | 29.9 |
| 10 | 273.0 | 444.5 | 254.5 | 47.70 | 117.3 | 273.0 | 320.5 | 323.8 | 16 | 28.40 | 387.3 | 42.7 |
| 12 | 323.8 | 520.7 | 304.8 | 50.80 | 130.0 | 323.8 | 374.6 | 381.0 | 16 | 31.70 | 450.8 | 61.8 |
| 14 | 355.6 | 584.2 | To be specified by the Purchaser |
53.80 | 142.7 | 355.6 | 425.4 | 412.7 | 20 | 31.70 | 514.3 | 85.8 |
| 16 | 406.4 | 647.7 | 57.15 | 146.0 | 406.4 | 482.6 | 469.9 | 20 | 35.00 | 571.5 | 106 | |
| 18 | 457.2 | 711.2 | 60.45 | 158.7 | 457.2 | 533.4 | 533.4 | 24 | 35.00 | 628.6 | 131 | |
| 20 | 508.0 | 774.7 | 63.50 | 162.0 | 508.0 | 587.2 | 584.2 | 24 | 35.00 | 685.8 | 158 | |
| 24 | 609.6 | 914.4 | 69.85 | 168.1 | 609.6 | 701.5 | 692.1 | 24 | 41.10 | 812.8 | 230 | |
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