What does schedule 40 seamless pipe mean?

Schedule 40 seamless pipe, this keyword involves two important concepts in the steel industry: seamless pipe and schedule 40. Seamless pipe is a special kind of steel pipe, and  schedule 40 is one of the specifications of seamless pipe.

1. Seamless pipe

Seamless pipe/tubing is a steel pipe made by billet heating, perforation, rolling and cooling. Compared with welded steel pipes, seamless pipes have obvious advantages in appearance and performance. First of all, it has a smooth appearance and no welded joints, so it has better aesthetics. Secondly, seamless pipes excel in strength and pressure resistance and can withstand higher pressures and temperatures. This makes seamless pipes widely used in some special fields, such as petroleum, chemical, natural gas and other industries.

2. Schedule 40 pipe specification mark

Schedule 40 pipe refers to a specification mark for seamless pipes, which represents the thickness of the pipe wall. Specifically, Schedule40 refers to seamless pipes with a wall thickness of 40S, where the "S" represents the standard wall thickness series. Schedule 40 is one of the common piping codes because it is moderately thick and is usually used in situations where it can withstand higher pressures and temperatures. Seamless steel pipes of this specification are widely used in petroleum, chemical industry, shipbuilding, heating and other industries.

Based on the NPS and schedule of a pipe, the pipe outside diameter (OD) and wall thickness can be obtained from reference tables such as those below, which are based on ASME standards B36.10M and B36.19M. For example, NPS 14 Sch 40 has an OD of 14 inches (360 mm) and a wall thickness of 0.437 inches (11.1 mm).
Sch 40 can be used for both Seamless steel pipes and ERW (Electric Resistance Welded) pipes.

SCH40, tube number, whether it is domestic or foreign, Sch.XX is used to indicate the wall thickness of the pipe. 
Pipe wall thickness grade Sch40, carbon steel, low alloy steel of a thickness class code, corresponding to a certain pipe thickness.

Sch40: indicates tensile strength, 40 kg pressure. It can be detected through standard thickness of 4.0mm. Tubes of different diameter, different pressures, different wall thickness.

3. Characteristics of schedule 40 seamless pipe

Schedule 40 seamless pipe has the following characteristics:
a. High strength: Sch40 pipe wall thickness is relatively large and can withstand high pressure and mechanical load.
b. Strong corrosion resistance: Seamless steel pipes are usually made of high-quality steel and can operate stably for a long time in harsh environments.
c. High dimensional accuracy: The production process of seamless steel pipe Sch40 is relatively precise and has high dimensional accuracy, making it suitable for occasions with strict dimensional requirements.

d. Wide application: Seamless steel pipe Sch40 is widely used in petroleum, chemical industry, heating, shipbuilding and other fields, and is used to transport various media such as liquids, gases and solids.

Pipes schedule 40 chart gives dimensions of steel pipes schedule 40. The chart includes sizes in inches and in millimeters.

Nominal size [inches]	Outside diameter [inches]	Outside diameter [mm]	Wall thickness [inches]	Wall thickness [mm]	Weight [lb/ft]	Weight [kg/m]
1/8	0.405	10.3	0.068	1.73	0.24	0.37
1/4	0.540	13.7	0.088	2.24	0.42	0.84
1/2	0.840	21.3	0.109	2.77	0.85	1.27
3/4	1.050	26.7	0.113	2.87	1.13	1.69
1	1.315	33.4	0.133	3.38	1.68	2.50
1 1/4	1.660	42.2	0.140	3.56	2.27	3.39
1 1/2	1.900	48.3	0.145	3.68	2.72	4.05
2	2.375	60.3	0.154	3.91	3.65	5.44
2 1/2	2.875	73.0	0.203	5.16	5.79	8.63
3	3.500	88.9	0.216	5.49	7.58	11.29
3 1/2	4.000	101.6	0.226	5.74	9.11	13.57
4	4.500	114.3	0.237	6.02	10.79	16.07
5	5.563	141.3	0.258	6.55	14.62	21.77
6	6.625	168.3	0.280	7.11	18.97	28.26
8	8.625	219.1	0.322	8.18	28.55	42.55
10	10.750	273.0	0.365	9.27	40.48	60.31
12	12.750	323.8	0.406	10.31	53.52	79.73
14	14	355.6	0.375	11.13	54.57	94.55
16	16	406.4	0.500	12.70	82.77	123.30
18	18	457.0	0.562	14.27	104.67	155.80
20	20	508.0	0.594	15.09	123.11	183.42
24	24	610.0	0.688	17.48	171.29	255.41
32	32	813.0	0.688	17.48	230.08	342.91

Summarize:

Schedule 40 seamless pipe is a seamless pipe specification with high strength, strong corrosion resistance and high dimensional accuracy. It plays an important role in petroleum, chemical industry, shipbuilding, heating and other industries. The use of schedule40 seamless pipe can ensure the stable operation of the pipeline and meet the requirements for various media transportation.

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