Slotted PK Drainage Pipe PipeKorr – Double-wall corrugated HDPE pipe with slots for drainage

The Slotted PK Drainage Pipe is the drainage version of the double-wall PipeKorr system. Manufactured in HDPE with a smooth inner wall and corrugated outer wall, it is processed with calibrated slots for the collection of rainwater and groundwater.

Available in SN4 class (≥ 4 kN/m²) for standard depths and SN8 class (≥ 8 kN/m²) for deep installations and heavy loads. Three slotting configurations are available: type A (360° around the full perimeter), type B (240°) and type C (120°), customizable on request. Complete range from DN 125 to DN 1200 mm.

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Slotted PK Drainage Pipe

Rigidity classes

The slotted PK Drainage Pipe is available in two rigidity classes. For the same diameter, dimensions and slotting configurations are identical: only the structural mechanical resistance changes.

SN4 class (≥ 4 kN/m²) for standard depths. 11 diameters from DN 125 to DN 1200. Type A (360°), B (240°) and C (120°) slotting with detailed tables for slotted area and number of slots per corrugation.

Parameter Value Unit
Annular stiffness ≥ 4 kN/m²
Resistance to heating 60 min
Annular flexibility 30 %
Available diameters DN 125–1200 mm
Format Bars ~6 m
Types of slotting A (360°), B (240°), C (120°)
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Technical specifications

Dimension table (both SN4 and SN8 classes)

OD/OD [mm] ID/ID [mm] e1 min e2 min L [mm]
125 106 1.1 1.0 6484
160 137 1.2 1.0 6474
200 172 1.4 1.0 6455
250 215 1.7 1.4 6433
315 272 1.9 1.6 6407
400 343 2.3 2.0 6378
500 433 2.8 2.8 6351
630 546 3.3 3.3 6354
800 686 4.1 4.1 6310
1000 856 5.0 5.0 6277
1200 1030 5.0 5.0 6179

Tolerance ± 10 mm up to OD 500 mm; from OD 500 ± 6%. Slotting may affect mechanical performance.

Types of slotting

The slots are made in the corrugated outer wall and are classified according to the circumferential coverage angle:

  • Type A — 360°: Slots distributed around the full perimeter. Maximum intake, ideal for uniformly saturated soils. From 3 to 8 slots per corrugation depending on diameter.
  • Type B — 240°: Slots distributed over 2/3 of the perimeter (240°). Good intake with a blind bottom for flow conveyance. From 2 to 5 slots per corrugation.
  • Type C — 120°: Slots concentrated on 1/3 of the perimeter (120°). Directional drainage, with the closed side oriented downward for conveyance. From 1 to 3 slots per corrugation.

Custom configurations available on request, subject to approval by the NTET technical office.

Structure and material

  • Material: High-Density Polyethylene (HDPE)
  • Structure: Double wall — smooth inside, corrugated outside (type B)
  • Colour: Black (both walls)

Standards

  • Annular stiffness: EN ISO 9969
  • Resistance to heating: ISO 12091
  • Annular flexibility: EN ISO 13968

Technical documentation

Scarica le schede tecniche complete con tabelle di fessurazione dettagliate per tipo A (360°), B (240°) e C (120°).

Applications

Slotted PK Drainage pipes are designed for the collection and conveyance of groundwater and rainwater in infrastructure applications.

  • Road and motorway drainage

    Collection of infiltration water along drainage trenches at the roadside. Type A slotting (360°) maximizes intake in uniform soils.

  • Foundation and retaining wall drainage

    Reduction of hydrostatic pressure behind retaining walls and around foundations. Type B slotting (240°) with blind bottom conveys water toward discharge points.

  • Agricultural drainage and land reclamation

    Regulation of the water table level in agricultural land. Calibrated slotting makes it possible to control the intake flow according to soil permeability.

  • Sports fields and green areas drainage

    Rapid removal of excess rainwater from the sub-base of sports fields and permeable surfaces.

  • Tunnel and underground works drainage

    Collection of infiltration water in road and railway tunnels. SN8 is preferable for the depths and loads typical of these applications.

FAQ

Type A (360°): for omnidirectional drainage in uniformly saturated soils. Type B (240°): when a blind bottom is required for flow conveyance (for example behind retaining walls). Type C (120°): for directional intake, with the closed side facing downward. The NTET technical office can recommend the optimal configuration for the project.

SN4 (≥ 4 kN/m²) is for standard installation depths. SN8 (≥ 8 kN/m²) is for deep installations and heavy loads. Dimensions, slotting and tables are identical: only the structural wall resistance changes.

Yes, the slotting process may slightly reduce mechanical performance compared with the non-slotted pipe. The annular stiffness, resistance to heating and annular flexibility values shown in the data sheets refer to the intact pipe. Consult the technical office for sizing based on the specific project.

Yes. In addition to standard types A, B and C, NTET can produce custom slotting configurations — different width, pitch, angle or combination — subject to approval by the technical office.

PK Drainage pipes are double-wall (smooth inside + corrugated outside), have SN4/SN8 annular stiffness and are available in diameters up to DN 1200 — intended for infrastructure and major works. Drainage from Conduit pipes are single-wall, with 450–750 N compression resistance, and cover small diameters (DN 63–200) — intended for building applications and cable ducts.

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