Bolts and gaskets are important in this order which we got from one of our regular customer. There are usually three parts combined into a spiral wound gasket, inner ring, outer ring and the filler. However, client require the inner and outer ring to be in different material. And the key point for bolts is they are required to be HDG, hot dipping galvanized, which will extend the delivery time. We have offered with the shortest term we can about the coating process and discussed it with the client to get the order.
Product List
| Description of Goods | Quantity (PCS) | |
| 1 | BTH,A320 L7, UNC, 70MM, 1IN, HDG | 26 |
| 2 | GASW,CL300,316,GPH,DN200 | 26 |
| 3 | SB2N,L7,4,UNC,1IN,130MM,HDG | 12 |
| 4 | SB2N,L7,4,UNC,1IN,130MM,HDG | 12 |
Inspection Photos
Specification For ASTM A320 L7 Bolts
ASTM A320 L7 Bolts This is the most common A320 bolt grade. A320 Grade L7 bolts and threaded studs are manufactured from alloy steel with chromium, manganese, and molybdenum. The bolts undergo a heat treating process to reach their required mechanical properties.
| ASTM | A320 L7 |
| Standard | ASME B18.2.1, B18.3 |
| Threads Configuration | ASME B1.1 2A/3A Inch Unified Threads and B1.13M 6h Metric Coarse Threads |
| Type | Stud Bolts, Heavy Stud bolt, Tie Bar, Tie Rod, Continuous Threaded Stud Bolts (Fully Threaded Studs without Chamfered Ends), Tap End Stud Bolts, Double End Stud Bolts, Double End Stud Bolts with Reduced Shank, Flange Stud Bolts (Fully Threaded Studs with Chamfered Ends), MS Stud Bolts, Metric Thread Stud Bolt, Rough Forged Stud Bolts, Stud Half Thread Bolts etc. |
| A320 Grade L7 Bolts Neck type | Square, Hex, Oval, Triangular & Knurled etc |
ASTM A320 Grade L7 Bolts Chemical Composition
| Element | Composition,%A |
| Chromium MolybdenumD | |
| Carbon,max | 0.38-0.48 |
| Manganese | 0.75-1.00 |
| Phosphorus,max | 0.035 |
| Sulfur,max | 0.040 |
| Silicon | 0.15-0.35 |
| Chromium | 0.80-1.10 |
| Molybdenum | 0.15-0.25 |
Mechanical Properties of ASTM A320 L7 Stud Bolts
| Grade | Size | Tensile ksi, min | Yield, ksi, min | Elong, %, min | RA % min |
| L7 | Up to 2-1/2 | 125 | 105 | 16 | 50 |
Bolts Applications
Mechanical Manufacturing: Used for assembling various machines, equipment, and components.
Construction: Used for connecting steel structures, bridges, and prefabricated components.
Automotive and Aerospace: Used for fastening key components such as engines, chassis, and fuselages.
Oil and Gas: Used for connecting pipelines, valves, and pressure vessels.
Spiral Wound Gasket
A Spiral Wound Gasket is the most common metallic gasket used in industrial plants. A properly selected and installed spiral wound gasket can withstand high temperatures and pressures, preventing leaks throughout their intended lifespan.
The spiral wound gasket has good sealing performance. Its spiral winding structure allows the metal belt and filling material to fit tightly on the sealing surface when the gasket is under pressure, filling the tiny unevenness of the sealing surface, thereby effectively preventing medium leakage. Spiral wound gaskets are widely used in the sealing of flange connections of pipelines, valves, pressure vessels, condensers, heat exchangers and other equipment in the petroleum, chemical, metallurgy, electric power, shipbuilding, machinery and other industries.
Spiral Wound Gasket Dimension
| Dimensions for Spiral-Wound Gaskets Used With ASME B16.5 Flanges | ||||||||||||||||
| Flange Size (NPS) | Outside Diameter of Gasket [Note(1)] | Inside Diameter of Gasket by Class [Notes(2). (3)] | Outside Diameter of Centering Ring by Class [Note(4)1 | |||||||||||||
| Classes 150,300, 400,600 | Classes 900,1500, 2500 | |||||||||||||||
| 150 | 300 | 400(5) | 600 | 900(5) | 1500 | 2500 (5) | 150 | 300 | 400(5) | 600 | 900(5) | 1500 | 2500(5) | |||
| 1/2 | 31.8 | 31.8 | 19.1 | 19.1 | 19.1 | 19.1 | 19.1 | 47.8 | 54.1 | 54.1 | … | 63.5 | 69.9 | |||
| 3/4 | 39.6 | 39.6 | 25.4 | 25.4 | 25.4 | 25.4 | 25.4 | 57.2 | 66.8 | 66.8 | 69.9 | 76.2 | ||||
| 1 | 47.8 | 47.8 | 31.8 | 31.8 | 31.8 | 31.8 | 31.8 | 66.8 | 73.2 | 73.2 | 79.5 | 85.9 | ||||
| 1 1/4 | 60.5 | 60.5 | 47.8 | 47.8 | 47.8 | 39.6 | 39.6 | 76.2 | 82.6 | 82.6 | 88.9 | 104.9 | ||||
| 1 1/2 | 69.9 | 69.9 | 54.1 | 54.1 | 54.1 | 47.8 | 47.8 | 85.9 | 95.3 | 95.3 | 98.6 | 117.6 | ||||
| 2 | 85.9 | 85.9 | 69.9 | 69.9 | 69.9 | 58.7 | 58.7 | 104.9 | 111.3 | 111.3 | 143.0 | 146.1 | ||||
| 2 1/2 | 98.6 | 98.6 | 82.6 | 82.6 | … | 82.6 | 69.9 | 69.9 | 124.0 | 130.3 | … | 130.3 | 165.1 | 168.4 | ||
| 3 | 120.7 | 120.7 | 101.6 | 101.6 | 101.6 | 95.3 | 92.2 | 92.2 | 136.7 | 149.4 | 149.4 | 168.4 | 174.8 | 196.9 | ||
| 4 | 149.4 | 149.4 | 127.0 | 127.0 | 120.7 | 120.7 | 120.7 | 117.6 | 117.6 | 174.8 | 181.1 | 177.8 | 193.8 | 206.5 | 209.6 | 235.0 |
| 5 | 177.8 | 177.8 | 155.7 | 155.7 | 147.6 | 147.6 | 147.6 | 143.0 | 143.0 | 196.9 | 215.9 | 212.9 | 241.3 | 247.7 | 254.0 | 279.4 |
| 6 | 209.6 | 209.6 | 182.6 | 182.6 | 174.8 | 174.8 | 174.8 | 171.5 | 171.5 | 222.3 | 251.0 | 247.7 | 266.7 | 289.1 | 282.7 | 317.5 |
| 8 | 263.7 | 257.3 | 233.4 | 233.4 | 225.6 | 225.6 | 222.3 | 215.9 | 215.9 | 279.4 | 308.1 | 304.8 | 320.8 | 358.9 | 352.6 | 387.4 |
| 10 | 317.5 | 311.2 | 287.3 | 287.3 | 274.6 | 274.6 | 276.4 | 266.7 | 270.0 | 339.9 | 362.0 | 358.9 | 400.1 | 435.1 | 435.1 | 476.3 |
| 12 | 374.7 | 368.3 | 339.9 | 339.9 | 327.2 | 327.2 | 323.9 | 323.9 | 317.5 | 409.7 | 422.4 | 419.1 | 457.2 | 498.6 | 520.7 | 549.4 |
| 14 | 406.4 | 400.1 | 371.6 | 371.6 | 362.0 | 362.0 | 355.6 | 362.0 | 450.9 | 485.9 | 482.6 | 492.3 | 520.7 | 577.9 | ||
| 16 | 463.6 | 457.2 | 422.4 | 422.4 | 412.8 | 412.8 | 412.8 | 406.4 | … | 514.4 | 539.8 | 536.7 | 565.2 | 574.8 | 641.4 | |
| 18 | 527.1 | 520.7 | 474.7 | 474.7 | 469.9 | 469.9 | 463.6 | 463.6 | 549.4 | 596.9 | 593.9 | 612.9 | 638.3 | 704.9 | ||
| 20 | 577.9 | 571.5 | 525.5 | 525.5 | 520.7 | 520.7 | 520.7 | 514.4 | 606.6 | 654.1 | 647.7 | 682.8 | 698.5 | 755.7 | ||
| 24 | 685.B | 679.5 | 628.7 | 628.7 | 628.7 | 628.7 | 628.7 | 616.0 | 717.6 | 774.7 | 768.4 | 790.7 | 838.2 | 901.7 | ||
How Bolts and Gaskets Work Together
In most fastening and sealing applications, bolts and gaskets are an inseparable pair. Bolts provide the necessary clamping force, firmly pressing the joints together. Gaskets, on the other hand, deform under the pressure exerted by the bolts, filling any irregularities in the joint surface and forming a tight barrier to prevent fluid leakage or structural loosening. For example, in a flange connection, bolts tightly connect the two flanges while simultaneously compressing the sealing gasket between them to prevent leakage of the pipeline media.
ZIZI specialize in selling all kinds of stainless steel pipe fittings, tubes, plates, flanges, bolts and nuts. our products are widely used in many fields, from precision machinery manufacturing to warm home decoration and even high-end aerospace industry. We have become a trusted choice for many industries due to our superior product quality and wide range of applications. Not only do we offer a wide range of products, but we can also provide customized processing services according to the specific needs of our customers, ensuring that your expectations are accurately met every time we work together. With advanced production equipment and strict quality management system, we are committed to providing high-quality piping solutions to customers worldwide. Welcome to contact us.