shouldered pipe

Pressure Pipes

A pressure pipe is an underground pipeline system used to transport liquids or gases under internal pressure. Pipes that meet three conditions are considered pressure pipelines:

  • Working pressure ≥ 0.1 MPa (approximately 1 kgf)
  • Pipe diameter ≥ 50 mm
  • Transporting gas/liquefied gas/steam/hazardous liquids or high-temperature liquids with a temperature ≥ the boiling point

As a carbon steel pipe manufacturer, we provide seamless and welded carbon steel pipes that comply with ASME, API and other standards, ensuring high strength, corrosion resistance and reliable operation to meet industrial and municipal needs.

size specification of Pressure Pipe

DN Outer Diameter Wall thickness (mm)
Inch mm SG105 SG1100 SG1101 SG120 SG130 SG140 SG140 SG180 SG1100 SG1102 SG1140 SG1140 Sln XS XGS  
50 2″ 60.3 1.65 2.77 3.91 5.54 8.74 3.91 5.54 11.07  
65 2 1/2″ 73 2.11 3.05 5.16 7.01 9.53 5.16 7.01 14.02  
80 3″ 88.9 2.11 3.05 5.49 7.62 11.13 5.49 7.52 15.24  
90 3 1/2″ 101.6 2.11 3.05 5.74 8.08 5.74 8.08  
100 4″ 114.3 2.11 3.05 6.02 8.58 11.13 13.49 6.02 8.56 17.12  
125 5″ 141.3 2.77 3.4 6.55 9.53 12.7 15.88 6.55 9.53 18.05  
150 6″ 168.3 2.77 3.4 7.11 10.97 14.27 18.26 7.11 10.97 21.95  
200 8″ 219.1 2.77 3.76 6.35 7.04 8.18 10.31 12.7 15.09 18.26 20.62 23.01 8.18 12.7 22.23
250 10″ 273.1 3.4 4.19 6.35 7.8 9.27 12.7 15.09 18.26 21.44 25.4 28.58 9.27 12.7 25.4
300 12″ 323.9 3.96 4.57 6.35 8.38 10.31 14.27 17.48 21.44 25.4 28.58 33.32 9.53 12.7 25.4
350 14″ 355.5 3.96 4.78 6.35 7.92 9.53 11.13 15.09 19.05 23.83 27.79 31.75 35.71 9.53 12.7
400 16″ 406.4 4.19 4.78 6.35 7.92 9.53 12.7 16.66 21.44 26.19 30.96 36.53 40.49 9.53 12.7
450 18″ 457.2 4.19 4.78 6.35 7.92 11.13 14.27 19.05 23.83 39.36 34.93 39.67 45.24
500 20″ 508 4.78 5.54 6.35 9.53 12.7 15.09 20.62 26.19 32.54 38.1 44.45 50.01
550 22″ 558.8 4.78 5.54 6.35 9.53 12.7 22.23 28.58 34.93 41.28 47.63 53.98
600 24″ 609.6 5.54 6.35 6.35 9.53 14.27 17.48 24.61 30.96 38.89 46.02 52.37 59.54

Pressure Pipe Standards

ASTM A53 Pipe – Grades A and B:

This is one of the most widely used carbon steel pipe standards in the United States, suitable for a wide range of general applications.

Main Applications:

  • Building Structures (for columns, supports, etc., especially Type F);
    Mechanical Structures: Low-pressure piping systems (steam, water, air, gas, oil, etc.);
  • Scaffolding, fencing, pressure pipe (must comply with applicable pressure pipe codes, such as ASME B31.1/B31.3); and protective casing.

EN 10255:

This European standard specifically covers steel pipe with threads and fittings, primarily for non-alloy steel piping systems. It is being gradually replaced by the EN 10217 and EN 10216 series, but it remains common in many existing projects, specialized applications (such as water and gas), and inventory.

Typical Applications:

  • Low-pressure fluid transportation: cold water, hot water, domestic gas (natural gas, liquefied petroleum gas), compressed air, and steam (low pressure). Building Services: Water, gas, and heating, ventilation, and air conditioning (HVAC) piping within buildings.
  • Threaded Systems: Pipe projects requiring on-site threaded connections.

EN 10217-1

This is part of a series of European standards specifically for welded steel pipes used in pressure systems. Part 1 specifies non-alloy (carbon) steel pipes with specified properties at room temperature.

Typical Uses:

  • Pressure Pipe Systems: Boilers, pressure vessels, and heat exchangers (shell and tube).
  • Industrial Piping: Pipes conveying various media (water, steam, oil, gas, and chemicals) in chemical and petrochemical plants, power plants, and ship piping systems.
  • Where Higher Strength and Reliability Required: Compared to EN 10255, it is suitable for systems with higher pressures and more stringent requirements.
  • Welded or Flange Connections: Typically used in engineering systems requiring welded or flanged connections rather than threaded connections.

JIS G3452 SGP:

A Japanese Industrial Standard for carbon steel pipes for general pipe applications. It is similar to ASTM A53 but is more commonly used in Japan and areas influenced by Japanese standards (such as some Asian projects).

Typical Uses:

  • Building Structures
  • Mechanical Structures
  • Low-Pressure Pipe Systems: Water, Steam, Air, Oil, Gas, etc.
  • Scaffolding
  • Protective Casing

AS 1074:An Australian Standard that provides a foundational specification for general requirements, materials, dimensions, tolerances, testing, and marking for steel pipes and fittings (both welded and seamless) for various applications.

It is often used in conjunction with specific product standards, such as AS 1163 – Welded and Seamless Steel Pipe for Structural Use. AS 1074 itself is not a product-specific technical specification, but rather defines general rules.

As a foundational standard, it applies to all applications covered by the specific steel pipe and fittings product standards that reference it, including:

  • Structural Pipe (Buildings, Bridges, Machinery)
  • Pipe for Piping (Water, Gas, Oil, Other Fluids)
  • Pile Pipe
  • Mechanical Pipe

Advantages of Our Pressure Pipe

In critical industrial areas, safety and reliability are of paramount importance. We provide durable pressure pipe products and services:

Excellent Product Performance

  • High-Pressure Resistance: Maximum operating pressures exceed 42 MPa, with burst pressures significantly exceeding the rated value (up to 2.5-4 times) to provide a robust safety margin for handling pressure fluctuations easily.
  • High Corrosion Resistance: Customized material options (such as super stainless steel and nickel-based alloys) are available for corrosive media such as acids, alkalis, oil and gas. The critical corrosion rate is strictly controlled to < 0.1 mm/year, significantly extending pipeline life (design life >20 years) and reducing maintenance and replacement costs.
  • Wide Adaptability: With the ability to withstand extreme temperatures ranging from -196°C to +800°C and excellent fatigue resistance, it ensures stable operation under complex operating conditions.

Professional Company Guarantee

  • Precision Customization: We provide customized solutions from design to manufacturing to meet your specific pressure, temperature, media and space requirements and solve unique engineering challenges.
  • Strict Quality Control: We hold a Class A manufacturing license for pressure pipe components for special equipment and adhere to a strict ISO 9001 quality management system. All products comply with core international and domestic standards (ASME, EN, GB/T).
  • Reliable Verification: Our production process is certified internationally. We use 100% non-destructive testing. Each pipe also goes through tough hydrostatic and pneumatic tests at design pressures. This ensures they are leak-tight and strong. Full material traceability is guaranteed.

Pressure Pipe Coating Types

– Fusion Bonded Epoxy (FBE) Coating

Fused bonded epoxy (FBE) coating is a thermally active powder coating based on epoxy resin, applied to metal surfaces via electrostatic spray technology. Its molecular structure has polar reactive epoxy groups. This creates a uniform, durable protective layer at high temperatures. As a result, it’s commonly used for corrosion protection on metal pipes, valves, and other equipment.

– Three-layer Polyethylene (3PE) Coating

Three-layer Polyethylene (3PE) coating provides superior corrosion protection and is widely applied to chemical pipelines in marine and harsh environments. The 3PE coating consists of a base layer of epoxy powder (FBE) or specialized adhesive, a middle layer of copolymer adhesive, and an outer layer of polyvinyl chloride. It is commonly utilized in the pharmaceutical, food and beverage, and water treatment sectors. Various types of internal coatings exist, such as epoxy coatings, which are ideal for acidic and alkaline conditions, and polytetrafluoroethylene (PTFE) coatings, which are perfect for low-friction, non-stick surfaces.This three-layer structure provides a strong synergistic effect, effectively preventing external corrosion on the pipe.

– Three-layer Polypropylene (3PP) Coating

3PP coating is a three-layer polypropylene anti-corrosion coating consisting of an epoxy powder base layer, a middle adhesive layer, and a polypropylene (PP) outer layer. The basecoat provides a good foundation for adhesion, the middlecoat is the core of the 3PP coating, and the topcoat primarily provides aesthetics and wear resistance.

– Epoxy Coal Tar Anticorrosive Coating

Epoxy coal tar anticorrosive coating consists of epoxy coal tar anticorrosive coating and a curing agent. It offers excellent corrosion resistance. It also exhibits excellent weathering and abrasion resistance. After high-temperature curing, epoxy coal tar anticorrosive coating forms a strong and ductile protective layer. It is widely used for corrosion protection in infrastructure such as oil and gas, bridges, and docks.

– Silicone Anticorrosive Coating

Silicone anticorrosive coating is a polymer coated with an organic silicone anticorrosive coating. It consists of polysiloxane, with silicon and oxygen atoms alternating to form a main chain and organic side chains. This compound is extremely chemically stable and resistant to corrosion from acids, alkalis, and salt media. It offers excellent stability and corrosion resistance. It is resistant to high temperatures and pressures, with an operating temperature of up to 600°C. It is commonly used in bridges, wind turbine towers, and petrochemical equipment.

– Internal Coating

Internal coating technology not only improves corrosion resistance on equipment surfaces but also enhances lubricity and reduces fluid resistance. It is widely used in the pharmaceutical, food and beverage, and water treatment industries. A variety of internal coatings are available, including epoxy coatings, which are suitable for acidic and alkaline environments, and polytetrafluoroethylene (PTFE) coatings, which are ideal for low-friction, non-stick surfaces.

FAQs

The pressure capacity of a pressure pipe depends on several factors:

  • Material: Carbon steel (such as Q235, 20#) generally withstands pressures ≤16 MPa; stainless steel (304/316) can withstand pressures above 25 MPa, and alloy steel (such as 15CrMo) can withstand pressures up to 100 MPa.
  • Design Standards: Comply with standards such as ASME B31.3 (process piping) and GB/T 20801 (domestic), and verify using wall thickness calculation formulas (such as *t = PD/(2SEW + 2PY)*).
  • Operating Conditions: Temperature, media corrosiveness (e.g., an increased corrosion allowance is required for acidic environments), and cyclic loading directly affect the allowable stress.

We recommend providing specific operating conditions (pressure/temperature/media) so we can accurately calculate the pressure rating.

We do, and the range includes:

  • Sizes: DN15 to DN3000 (diameter), wall thickness 0.5 to 50 mm. Materials: Carbon steel, stainless steel (304/316L/duplex steel), alloy steel (P91, Inconel), titanium alloy, etc.
  • Processing: Seamless, welding (ERW/SAW), heat treatment (annealing/solutionizing), surface treatment (sandblasting/pickling/polishing).
  • Certifications: PED (EU), ASME, GB/T, etc., available.

Pressure pipes are mainly used in:

  • Petrochemical: Crude oil transportation, reactor pressure piping, cracking units
  • Energy and power: Power plant boiler piping, steam transportation, nuclear power cooling systems
  • Food and pharmaceutical: Clean fluid transportation, fermentation tank piping (316L electrolytic polishing)
  • Shipbuilding: Fuel/lubricating oil piping, seawater cooling systems
  • Semiconductor: High-purity gas transportation (EP-grade stainless steel pipe)

Selection Recommendations:

  • Corrosive Environments (seawater, acidic media) → 316L Stainless Steel/Duplex Steel
  • High-Temperature and High-Pressure Steam (≤425°C) → Carbon Steel + Insulation
  • Food/Pharmaceutical → 316L Electropolished (Ra ≤ 0.8μm)

Standard products take one to two weeks (stock available, common specifications available). For custom requirements, please contact a UNIASEN piping expert for project evaluation and lead time.

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