HPL Tubes are seamless, cold-drawn precision steel tubes primarily utilized as pressure lines in hydraulic or pneumatic systems. They can be connected using both detachable and non-detachable fittings. These tubes must withstand velocity and pressure changes, leading to pressure surges superimposed on the static internal pressure during operation.

 

- Outside Diameter: 4 - 120 mm*

- Wall Thickness: 1.0 - 12.5 mm

- Standard Length: 6 m +10/-0 mm (Other dimensions available upon request)

- *Dimensions and deviation limits:

  - For OD 4 mm ≤ OD ≤ 80 mm: DIN EN 10305-4

  - For OD > 80 mm: DIN EN 10305-1 Table 5

 

- Adheres to detailed delivery program specifications for outside and inside diameter dimensions and tolerances.

- Straightness in accordance with EN 10305-4.

- Maximum permissible eccentricity for tubes ordered by outside diameter and inside diameter is 7.5%.

- Standard length of 6,000 mm -0/+10 mm, with shorter lengths down to 4,000 mm bundled separately.

 

- Steel grades: E 235 or E 355 as per EN 10305-4.

- Chemical Composition (maximum values):

  - E235: C 0.17%, Si 0.35%, Mn 1.20%, P 0.025%, S 0.015%

  - E355: C 0.22%, Si 0.55%, Mn 1.60%, P 0.025%, S 0.015%

  - Minimum aluminum content regulated, with allowances for nitrogen-binding elements (Nb, Ti, V).

 

- E235:

  - Tensile Strength (Rm): 340 - 480 MPa

  - Yield Strength (ReH): 235 MPa

  - Elongation (A): 25%

- E355:

  - Tensile Strength (Rm): 490 - 630 MPa

  - Yield Strength (ReH): 355 MPa

  - Elongation (A): 22%

  - For OD ≤ 30 mm and wall thickness ≤ 3 mm, ReH minimum values are 10 MPa lower.

Steel Grade	Tensile Strength Rm (MPa)	Yield Strength ReH (MPa)	Elongation A % (min)
E235	340 - 480	235	25
E355	490 - 630	355	22

 

- Cold Workability: Suitable for cold working due to final heat treatment. Bending causes a decrease in wall thickness and out-of-roundness. Reduction factors for bends and non-circular cross-sections are given in DIN 2413 Part 2.

- Weldability: Tubes can be welded without preheating using standard welding techniques.

 

- Technical Delivery Conditions: Tubes are normalized (+N) in a controlled atmosphere according to EN 10305-4.

- Surface Condition: Smooth inside and outside surfaces with roughness Ra ≤ 4 μm as per EN 10305-4.

- Passivation: Externally galvanized with a zinc coating (12 to 15 μm) plus a passivation layer. Cr(VI)-free coating complies with Directive 2000/53/EG.

  - Resistance to Corrosion: White rust resistance ≥ 300 h for OD < 20 mm, ≥ 200 h for OD ≥ 20 mm (ISO 9227). Red rust resistance ≥ 400 hours for all dimensions.

  - Temporary Corrosion Protection: Inhibitor-containing mineral oil coating:

    - Black tubes: oil-coated internally and externally.

    - Galvanized tubes: non-greased or oiled depending on dimensions.

 

- Standard: Smooth un-machined.

- Exception: Pinched off ends for tubes with OD < 8 mm or ID ≤ 4 mm.

- End Seal: Plastic end caps for ID ≤ 4 mm, plastic plugs for ID > 4 mm. Tubes ≤ 42 mm OD and non-standard lengths have open ends protected with blue plastic bags.

 

- Testing: Conducted as per DIN EN 10305-4. Additional inspections can be arranged.

- Inspection Certificates: Supplied with a 3.1 inspection certificate as per EN 10204. A 3.2 inspection certificate is available upon request.

 

- Continuous full-length marking including:

  - Manufacturers mark

  - Tube type

  - Dimensions

  - Delivery standard

  - Steel grade

  - Delivery condition

  - Batch number

  - Additional information

  - Country of Origin

  - Example: Lordtubing HPL 15 x 11 x 2 EN 10305-4 E235 +N 3484711 Cr6-free MADE IN CHINA

 

- Tubes ≥ 15 mm OD: Packed in steel-strapped hexagonal bundles.

- Short Lengths & Tubes < 15 mm OD: Supplied in round bundles.

- Custom Packaging: Crates, cardboard tubes, or bundles with foil available by agreement. Crate packing recommended for thin-walled tubes and overseas shipments.