The designation "DN 17175" is a combination of two separate standards that define the pipe's dimensions and material.
DN 150: This is the Diameter Nominal (DN) metric designation. It specifies the pipe's approximate internal diameter in millimeters. A DN 150 pipe is roughly equivalent to a 6-inch NPS (Nominal Pipe Size) pipe.
PN 175: This is the Pressure Nominal (PN) rating. It indicates the maximum design pressure the pipe can handle in bar at 20°C. PN 175 is an extremely high-pressure rating, equivalent to 175 bar (~2550 psi or ~17.5 MPa).
When combined, DN 17175 refers to a carbon steel pipe with a nominal diameter of 150mm (6 inches) and a pressure rating of 175 bar.
Key Specifications and Standards
This pipe would typically be manufactured to a specific international standard that defines its dimensions, tolerances, and material properties. The most common standard for such high-pressure pipes is:
EN 10216 / EN 10217: These are European standards for seamless and welded steel tubes for pressure purposes.
ASTM A106 / A53: These are common American standards for seamless and welded carbon steel pipe. For PN 175, the seamless (ASTM A106) version is almost always used.
ASME B36.10M: This standard defines the exact dimensions (outer diameter, wall thickness) for pipe sizes.
Dimensions for DN 150 (NPS 6) Pipe
For a DN 150 pipe, the standard outside diameter (OD) is 168.3 mm.
The wall thickness for a PN 175 rating would be classified as an Extra Strong (XS) or Double Extra Strong (XXS) schedule.
Common Wall Thickness for PN 175: You would be looking at a schedule XXS pipe.
OD: 168.3 mm
Wall Thickness (approx.): 18.26 mm (0.719 inches)
Schedule: 160 (Metric) / XXS (Imperial)
Inside Diameter (ID): OD - (2 x Wall Thickness) = 168.3 - (2 x 18.26) ≈ 131.8 mm
Important Note: The exact wall thickness must be confirmed with the manufacturer's data sheets or the relevant material standard (like EN 10216-2 for seamless pipes), as PN ratings can correspond to different wall thicknesses depending on the steel grade.
Material: Carbon Steel
The pipe is made from carbon steel, which is an alloy of iron and carbon. For high-pressure applications, the specific grade is critical. Common grades include:
P235GH (EN Standard): A non-alloy quality steel for elevated temperature service.
P265GH (EN Standard): A slightly higher strength grade.
ASTM A106 Grade B: This is the most common grade for high-temperature service. It has a minimum yield strength of 240 MPa and tensile strength of 415 MPa.
Applications
Due to its very high pressure rating, DN 17175 carbon steel pipe is used in demanding industrial applications, such as:
High-Pressure Steam Lines: In power plants and industrial process plants.
Oil & Gas Transmission: For main lines and gathering lines with high wellhead pressures.
Hydraulic Lines: In large industrial machinery requiring ultra-high pressure fluid power.
Process Piping: In chemical, petrochemical, and fertilizer plants where high-pressure fluids are transported.
Boiler Tubes: As part of the pressure circuit in high-pressure boilers.
Advantages and Disadvantages
| Advantages | Disadvantages |
|---|---|
| High Strength: Withstands extreme internal pressures. | Very Heavy: Difficult to handle, transport, and install. |
| Durability: Resistant to mechanical damage. | High Cost: More material required, leading to higher price. |
| High-Temperature Resistance: Suitable for steam and hot fluids. | Difficult to Fabricate: Requires specialized tools for cutting, welding, and threading. |
| Widely Available: Standard size and material. | Potential for Corrosion: Like all carbon steel, it requires protection (painting, coating) if used in corrosive environments. |
Summary
DN 17175 Carbon Steel Pipe is a heavy-duty, high-pressure pipe with a 150mm nominal bore. Its defining characteristic is its very thick wall, which allows it to operate safely in systems with pressures up to 175 bar. It is a critical component in power generation, oil and gas, and other heavy industries where safety and reliability under extreme conditions are paramount. When sourcing this pipe, always specify the complete material standard (e.g., EN 10216-2 P235GH) to ensure you get the correct product for your application.
