Schedule 80 Carbon Steel Pipe

What is Schedule 80 Carbon Steel Pipe?

Schedule 80 Carbon steel pipe is a carbon steel pipe manufactured according to ASME B36.10 (seamless and welded pipe) standard. Its wall thickness is thicker than Sch 40, with higher pressure bearing capacity and mechanical strength.

Standard material: Common grades include ASTM A106 (seamless), ASTM A53 (welded), API 5L (pipeline steel).
Size range: 1/8"~24" (DN6~DN600), larger sizes need to be customized.
Wall thickness grade: The wall thickness of Sch 80 is about 1.5~2 times that of Sch 40 (for example, the wall thickness of 2" Sch 40 is 3.91mm, while that of Sch 80 is 5.54mm).

Schedule 80 Carbon Steel Pipe is made up of carbon steel materials. The carbon steels can vary in composition based on the grades. The strengths and the toughness vary. To have an international and equal identification of the pressure capacities of the pipes, the schedule scale is used. The Schedule 80 Carbon Steel Pipe means that it has schedule 80 characteristics. There are schedules 5 to 160. 5 is the least pressure capable and 160 is the most pressure capable.

So the Schedule 80 Pipe Dimensions would be in half way through the spectrum. The nominal bore sizes range from 1/8 inches through 6 inches and the internal and external diameters vary. This in turn affects the wall thickness to vary from 0.095mm to 0.432mm. So the Schedule 80 Pipe Pressure Rating depends on all of these factors; the wall thickness, the diameter and the material grade. The stronger materials don’t need to have thicker walls to be in schedule 80. The Schedule 80 Pipe Thickness In Mm ranges only from 0.095mm to 0.432. The applications of the carbon steels pipes are in the less corrosive, high toughness and high wear and tear applications. The Schedule 80 Pipe Weight differs based on the grade, wall thickness, diameter and length of the pipe. Please contact us for more information and pricings.

Pipe Sch 80 Chart, Dimensions, Weight And Pipe Wall Thickness

Characteristics of Sch 80 steel pipe:

1. High pressure resistance: It can withstand higher pressure (usually above 300~500 psi) and is suitable for harsh working conditions.
2. Corrosion resistance: It is more resistant to wear and corrosion than Sch 40 (but requires galvanizing/coating for enhanced protection).
3. Mechanical strength: It has stronger pressure and impact resistance and is suitable for heavy-duty environments.
4. Weldability: Carbon steel is easy to weld (preheating is required to prevent cracks).
5. Weight & cost: It is heavier and more expensive than Sch 40 pipe, but the cost performance is better than stainless steel.

Typical applications of Sch 80 carbon steel pipe:

(1) Industrial high pressure system
Petroleum & Natural gas: high-pressure transmission pipelines, wellhead equipment.
Chemical/pharmaceutical: used to transport corrosive media (requires lining or coating), high-pressure reactor pipelines.
Power industry: boiler feed water, steam pipelines (Sch 80 resistant to high temperature and high pressure).

(2) Fire protection system
High-pressure fire main pipeline: fire hydrant system, fire pump outlet pipeline.
Industrial fire protection: chemical plants, oil depots and other high-risk places.

(3) Buildings & Infrastructure
Structural support: heavy scaffolding, bridge load-bearing components.
Underground buried pipes: high-pressure municipal water supply and drainage systems, requiring anti-corrosion treatment.

(4) Special purposes
Compressed air system: factory high-pressure pneumatic pipelines (≥150 psi).
Shipbuilding & marine engineering: resistant to seawater corrosion (requires galvanizing or special coating).

Sch 80 carbon steel pipe selection considerations:

a. Pressure calculation: Check the design pressure according to ASME B31.3 and other specifications.

b. Corrosion protection: In acidic/humid environments, galvanizing, epoxy coating or stainless steel are recommended. 

c. Temperature limit: Carbon steel Sch 80 long-term working temperature ≤400°C, higher temperatures require alloy steel. 

d. Alternatives: For extreme conditions, consider higher wall thickness Sch 160, seamless pipe or alloy steel pipe. 

FAQ:

Q1: What is the difference between SCH 80 steel pipe and SCH 40 steel pipe? 

A1: SCH 80 has thicker wall thickness than SCH 40 and has stronger pressure bearing capacity. 

Pressure rating: 

SCH 40 is suitable for medium and low pressure (usually ≤200 psi), such as building water supply and drainage, low-pressure gas. 

SCH 80 is suitable for high pressure (300~1000 psi, depending on the material), such as chemical high-pressure pipelines, fire mains, steam systems. 

Cost: SCH 80 is more expensive, but safer. SCH 80 is 30%~50% more expensive than SCH 40 (due to increased wall thickness and more material consumption).

Q2: How high a pressure can SCH 80 steel pipe withstand?

A2: Carbon steel (A106 Gr.B): about 300~600 psi (depending on pipe diameter and temperature).
Stainless steel (316): about 500~800 psi.
Higher pressure: SCH 160 or seamless alloy steel pipe is required.

Q3: Can SCH 80 steel pipe be used in fire protection systems?

A3: Yes, but it is mainly used for high-pressure fire protection main pipelines, such as: fire hydrant systems, industrial fire protection (chemical plants, oil depots, etc.).
Not applicable: low-pressure sprinkler systems (usually SCH 40 can meet the requirements).

Q4: Can SCH 80 steel pipes be buried underground?

A4: Yes, but anti-corrosion treatment is required:
Coating protection: such as 3PE (polyethylene coating), epoxy coal tar.
Cathode protection: with sacrificial anode or impressed current.
Direct burial is not recommended: wet soil will corrode carbon steel and shorten its life.

Q5: What is the maximum temperature resistance of SCH 80 steel pipe?

A5:
Carbon steel (A106): ≤ 400°C for long-term use, up to 450°C for short-term use.
Stainless steel (316): ≤ 800°C for long-term use (oxidizing environment).
Higher temperature: alloy steel (such as P91) or ceramic lined pipe is required.

Conclusion:
Schedule 80 carbon steel pipe is an ideal choice for applications requiring high pressure, high strength and durability, especially for the fields of petroleum, chemical, fire protection and heavy industry. When selecting, you need to choose the appropriate material (carbon steel, stainless steel, galvanized, etc.) according to the pressure, medium and environment, and follow the relevant industry standards (such as ASTM, ASME). For high pressure or corrosive environments, it may be necessary to upgrade to a higher grade wall thickness or special material pipe. Consult a professional engineer if necessary.

Read more: Schedule 40 Carbon Steel Pipe