ASTM A795 Grade A
ASTM A795 Grade A
ASTM A795 Grade A is a type of steel grade specifically intended for use in sprinkler pipe applications. It is available in both seamless and welded varieties, and each offers its benefits. Seamless pipes are often considered to be stronger and more durable, while welded pipes are typically easier to install. Both types of pipe are available in a variety of sizes to suit different applications. ASTM A795 Grade A steel is a high-quality material that can offer long-term durability and performance in a wide range of environments. When selecting this steel grade for your next project, be sure to consider the advantages and disadvantages of both seamless and welded options to find the best fit for your needs.
ASTM A795 is the standard specification for black and hot-dipped galvanized welded and seamless steel pipe. This pipe is used for fire sprinkler systems because it is able to withstand high temperatures. The wall thickness of the pipe is listed in the table below. This standard is important because it helps to ensure that the pipe will be durable and will not fail under intense conditions. When choosing a pipe for a fire sprinkler system, it is important to make sure that it meets the requirements of ASTM A795. This will help to ensure that the system will be effective and will not cause any damage to the building or its occupants.
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Since 1998, Tianjin United Steel Pipe Co., Ltd (TUSPIPE) has been committed to supplying high-quality line pipes.
With over 500,000 tons annual production capacity, the company serves various fields and industries, such as oil & gas exploitation and transmission, ship & auto-building, water & electricity, environmental protection, mechanical engineering, infrastructure construction and etc.
TUSPIPE places a premium on product quality and rigorous product quality control. In order to maintain good product quality, the company has established a Test & Inspection Center since 2004. With a series of state-of-the-art tests and inspection equipment, the test & inspection center is able to perform the tensile tests, hydro tests, impact tests, DWTT, etc.
Chemical Composition of ASTM A795 Grade A
The ASTM A795 Grade A covers black and hot-dipped galvanized welded steel pipes. This standard applies to the following types of pipes: Type E—Electric-resistance-welded, Grades A and B; and Type S—Seamless, Grades A and B. When doing a chemical composition analysis on the pipes, two pipes must be sampled from each lot of 500 lengths, or a fraction thereof. The table below outlines the requirements for the chemical composition. The results of the analysis must conform to these requirements to be considered compliant with the standard.
| Steel Grade | C, max | Mn | P | S | Mo | Ni | Cr | Cor | Others |
| Grade A | 0.25 | 0.95 | 0.035 | 0.035 | – | – | – | – | – |
Dimensions, Weights, and Test Pressure for ASTM A795 Grade A Pipe
| TABLE 1 Dimensions, Weights, and Test Pressure for Light-Weight Fire Protection ASTM A795 Pipe—Schedule 10A | ||||||||||
| NPS Designator | Outside Diameter | Nominal Wall Thickness | Weight Plain End | Test Pressure | ||||||
| Furnace-Welded | Seamless and Electric-Resistance-Welded | |||||||||
| in. | mm | in. | mm | lb/ft | kg/m | psi | MPa | psi | MPa | |
| 3/4 | 1.05 | (26.7) | 0.083 | (2.11) | 0.86 | (1.280) | 500 | (3.45) | 700 | (4.83) |
| 1 | 1.315 | (33.4) | 0.109 | (2.77) | 1.41 | (2.090) | 500 | (3.45) | 700 | (4.83) |
| 1.25 | 1.66 | (42.2) | 0.109 | (2.77) | 1.81 | (2.690) | 500 | (3.45) | 1000 | (6.89) |
| 1 1/2 | 1.9 | (48.3) | 0.109 | (2.77) | 2.09 | (3.110) | 500 | (3.45) | 1000 | (6.89) |
| 2 | 2.38 | (60.3) | 0.109 | (2.77) | 2.64 | (3.930) | 500 | (3.45) | 1000 | (6.89) |
| 2 1/2 | 2.88 | (73.0) | 0.12 | (3.05) | 3.53 | (5.260) | 500 | (3.45) | 1000 | (6.89) |
| 3 | 3.5 | (88.9) | 0.12 | (3.05) | 4.34 | (6.460) | 500 | (3.45) | 1000 | (6.89) |
| 3 1/2 | 4 | (101.6) | 0.12 | (3.05) | 4.98 | (7.410) | 500 | (3.45) | 1200 | (8.27) |
| 4 | 4.5 | (114.3) | 0.12 | (3.05) | 5.62 | (8.370) | 500 | (3.45) | 1200 | (8.27) |
| 5 | 5.56 | (141.3) | 0.134 | (3.40) | 7.78 | (11.580) | B | B | 1200 | (8.27) |
| 6 | 6.63 | (168.3) | 0.134 | (3.40) | 9.3 | (13.850) | B | B | 1000 | (5.51) |
| 8 | 8.63 | (219.1) | 0.188C | (4.78) | 16.96 | (25.260) | B | B | 800 | (4.83) |
| 10 | 10.75 | (273.1) | 0.188C | (4.78) | 21.23 | (31.620) | B | B | 700 | (6.89) |
| A：Schedule 10 corresponds to Schedule 10S as listed in ANSI B 36.19 for NPS 3⁄4 through 6 only. | ||||||||||
| B：Furnace-welded pipe is not made in sizes larger than NPS 4. | ||||||||||
| C：Not Schedule 10. | ||||||||||
| TABLE 2 Dimensions, Weights, Test Pressures for Standard-Weight Fire Protection ASTM A795 Pipe—Schedule 30 and Schedule 40 | ||||||||||
| NPS Designator | Outside Diameter | Nominal Wall Thickness | Weight Plain End | Test Pressure | ||||||
| Furnace-Welded | Seamless and Electric-Resistance-Welded | |||||||||
| in. | mm | in. | mm | lb/ft | kg/m | psi | MPa | psi | MPa | |
| 1/2 | 0.84 | (21.3) | 0.109 | (2.77) | 0.85 | (1.270) | 700 | (4.83) | 700 | (4.83) |
| 3/4 | 1.05 | (26.7) | 0.113 | (2.87) | 1.13 | (1.690) | 700 | (4.83) | 700 | (4.83) |
| 1 | 1.32 | (33.4) | 0.133 | (3.38) | 0.68 | (2.500) | 700 | (4.83) | 700 | (4.83) |
| 1 1/4 | 1.66 | (42.2) | 0.14 | (3.56) | 2.27 | (3.390) | 1000 | (6.89) | 1000 | (6.89) |
| 1 1/2 | 1.9 | (48.3) | 0.145 | (3.68) | 2.72 | (4.050) | 1000 | (6.89) | 1000 | (6.89) |
| 2 | 2.38 | (60.3) | 0.154 | (3.91) | 3.66 | (5.450) | 1000 | (6.89) | 1000 | (6.89) |
| 2 1/2 | 2.88 | (73.0) | 0.203 | (5.16) | 5.8 | (8.640) | 1000 | (6.89) | 1000 | (6.89) |
| 3 | 3.5 | (88.9) | 0.216 | (5.49) | 7.58 | (11.290) | 1000 | (6.89) | 1000 | (6.89) |
| 3 1/2 | 4 | (101.6) | 0.226 | (5.74) | 9.12 | (13.580) | 1200 | (8.27) | 1200 | (8.27) |
| 4 | 4.5 | (114.3) | 0.237 | (6.02) | 10.8 | (16.090) | 1200 | (8.27) | 1200 | (8.27) |
| 5 | 5.56 | (141.3) | 0.258 | (6.55) | 14.63 | (21.790) | C | C | 1200 | (8.27) |
| 6 | 6.63 | (168.3) | 0.28 | (7.11) | 18.99 | (28.290) | C | C | 1200 | (8.27) |
| 8 | 8.63 | (219.1) | 0.277A | (7.04) | 24.72 | (36.820) | C | C | 1200 | (8.27) |
| 10 | 10.75 | (273.1) | 0.307A | (7.80) | 34.27 | (51.050) | C | C | 1000 | (6.89) |
| A：NPS 1⁄2 through 6—Schedule 40; NPS 8 and 10—Schedule 30. | ||||||||||
| B：Based on 20-ft (6.1-m) lengths. | ||||||||||
| C：Furnace-welded pipe is not made in sizes larger than NPS 4. | ||||||||||
Test Requirements of ASTM A795 Grade A Pipe
- Hydrotest of ASTM A795 Grade A Pipes
The hydrostatic test is a very important part of the manufacturing process for ASTM A795 Grade A pipes. This test ensures that the pipe will be able to withstand the high pressures that it will be subjected to in its intended application. The test involves filling the pipe with water and then subjecting it to very high pressure. If there are any leaks in the pipe, they will be revealed during this test. The hydrostatic test is an essential part of the manufacturing process for pipes and helps to ensure that the finished product is of high quality.
- Nondestructive Electric Test of ASTM A795 Grade A Pipes
The ASTM A795 standard outlines a nondestructive electric test that can be used as an alternative to the hydrostatic test. This test involves sending an electric current through the pipe and then measuring the resistance of the pipe material. If the pipe material is resistant to the current, it is likely that it is strong enough to withstand the stresses of use. This test is less destructive than the hydrostatic test, which involves filling the pipe with water and then measuring the pressure required to break the pipe. As a result, the nondestructive electric test is often seen as a more efficient and reliable method for testing pipes.
- Flattening Test of ASTM A795 Grade A Pipes
The standard requires that a flattening test be performed on ASTM A795 Grade A pipes to assess their ductility. The pipes are flattened between parallel plates in 3 steps, with the weld located either 0 or 90 degrees from the line of force.
- The first test is for the ductility of the weld. This tests to see if any cracks or breaks occur on the inside or outside surfaces until the distance between the plates is less than two-thirds of the original outside diameter of the pipe.
- The second test is for ductility exclusive of the weld. This test is to see if any cracks or breaks occur on the inside or outside surfaces until the distance between the plates is less than one-third of the original outside diameter of the pipe, but is not less than five times the wall thickness of the pipe.
- The third and final test is for soundness. This test is conducted by continuing the flattening until the specimen breaks or the opposite walls of the specimen meet. Evidence of laminated or unsound material or incomplete weld that is revealed during this flattening test shall be cause for rejection.
Coating of ASTM A795 Grade A Pipes
ASTM A795 Grade A galvanized pipe is coated with zinc on both the inside and outside by the hot-dip process. The zinc used for the coating must conform to the specification laid out in the galvanized pipes requirements. The pipe shall be free from uncoated areas, blister, flux deposits, and gross dross inclusions. Lumps, projections, globules, or heavy deposits of zinc that will interfere with the intended use of the material are not permitted. The pipe shall be free from cracks, holes, or other defects that would cause leaks. All joints in the pipe shall be watertight. The ends of the pipe shall be prepared for connection to fittings or other pipes in such a way that there will be no difficulty in making a leakproof joint.
