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PLB Duct Pipes

PLB Duct Pipes

AS PER TEC / GR SPECIFICATIONS

HDPE Permanently Lubricated Ducts for Utility Networks

Every digital and utility connection, from fibre internet and telecom to power and smart city networks, depends on protected underground cabling. NATRAJ PLB Permanently Lubricated Duct Pipes create a safe, durable pathway for OFC and other utility cables, enabling faster, smoother and more reliable installation.

Co extruded from virgin HDPE, the duct combines a silicone enriched low friction inner layer with a UV stabilised outer sheath to support long pulls across varied ground conditions. Tight OD and ID control, low ovality and uniform wall thickness deliver a smooth, consistent bore, while colour coding, tracer stripes, continuous print line and metre marking support on site identification and traceability.

Designed for blowing, jetting and controlled hauling, the round snag free bore helps protect cable sheath integrity and supports long continuous runs with fewer joints. Permanent lubrication is created through a silicone enhanced lubricity package locked into the inner layer during co extrusion, delivering predictably low drag and retaining performance after ageing and moisture exposure. Typical dynamic coefficient of friction can be ≤ 0.06 with standard optical fibre cables. Actual values depend on cable design, installation method and site conditions.

Natraj PLB Duct Pipes are available in standard sizes suitable for OFC and other underground utility cabling, with options for project specific customisation.

  • Standard Sizes: 32/26 mm, 40/33 mm, 50/42 mm (other sizes on request)

  • Coil Lengths: 1000 m, 500 m, 200 m (custom coil lengths on request)

  • Colours and Coding: Green, orange, red, yellow, grey, with single or double tracer stripes as per client coding scheme

  • Construction: Co extruded duct with permanently lubricated low friction inner layer and UV stabilised outer sheath

  • Material Grade: Virgin HDPE conforming to IS 4984 classification, PE grades such as PE63, PE80, PE100 as specified in the order

  • Compliance Reference: Produced to relevant Indian requirements and TEC and GR specifications for PLB ducts, with test methods referenced to IS, ASTM and ISO as applicable

Natraj PLB Duct Pipes are designed to create a protected underground pathway for fibre and utility cables across long haul, access and last mile networks, and mission critical infrastructure.

  • National and regional backbones including inter city links and metro rings

  • Access and last mile FTTx networks including FTTH and FTTB distribution

  • Rail and transit networks including signalling and operations communication

  • Roads and intelligent transport systems including highways, toll plazas and CCTV backbones

  • Airports and ports including terminal connectivity and yard communication routes

  • Utilities and energy networks including SCADA and automation links for power, water and gas utilities

  • Campuses and data estates including IT parks, universities, hospitals and industrial estates

  • Smart city and security networks including city Wi Fi, surveillance and IoT sensor grids

  • Rural and community broadband corridors including gram panchayat connectivity

  • Defence and critical facilities requiring secure communication routes

Natraj PLB Duct Pipes are engineered to improve installation speed, protect cable integrity and deliver dependable service life in varied ground and climate conditions.

  • Virgin HDPE construction delivers long term strength and underground durability
  • Low friction inner lining enables smoother pulling, blowing and jetting with reduced drag
  • Permanent lubrication locked into the inner layer delivers uniform lubricity and retains performance after ageing and moisture exposure
  • High crush and impact strength supports trench loads, handling shocks and settlement conditions
  • Controlled ovality and tight OD and ID tolerances maintain roundness for snag free cable passage and long continuous runs
  • UV stabilised outer sheath supports outdoor storage and exposed route requirements
  • High ESCR resistance reduces risk of environmental stress cracking in real world installation environments
  • Clear identification and traceability through customer colour, tracer stripe options, continuous print line and metre marking for easy site control
  • Standards aligned manufacturing with TEC GR references and IS, ASTM, ISO test methods as applicable, supporting consistent quality across projects
  • Long service life and system reliability supporting utility and telecom network uptime

Parameter Details

Size range

32/26 mm, 40/33 mm, 50/42 mm (other sizes on request)

Colours and coding

Green, orange, red, yellow, grey; customer colour schemes with single or double tracer stripes

Coil lengths
1000 m, 500 m, 200 m (custom coil lengths on request)

Material grade (base resin)

Virgin HDPE conforming to IS 4984:1995 classification (PE grades such as PE63 / PE80 / PE100 as specified in the order)

Compliance and references

Produced to relevant Indian requirements and TEC/GR for PLB ducts; test methods referenced to IS, ASTM, ISO as applicable

PLB DUCT 40/33 MM
Parameter / Test Method / Standard Requirement

Density

ASTM F2160

0.940–0.955 g/cc

Melt flow index

ASTM F2160

< 0.55 g / 10 min

Workmanship and finish

ASTM F2160

Co extruded layers to be homogeneous and uniform in colour opacity density; inner and outer surfaces free from visible defects such as cracks, blisters, holes, voids, inclusions

Dimensions and tolerances

Drawing / QAP

OD 40.0 ± 0.4 mm; wall thickness 3.3–3.7 mm

Silicone inner layer thickness

GR No. GR/CDS/08/02

0.28–0.42 mm

Identification stripes

ASTM F2160

Tracer stripe(s) provided as per customer coding scheme

End roundness at cut (toe in)

ASTM F2160

OD at cut end ≤ 1.5% lower than OD measured 300 mm from the end

Lubrication system compatibility

ASTM F2160

Lubricant compatible with conduit material and common cable jackets

Crush resistance

ASTM F2412

After 15% deflection, duct recovers ≥ 95% within 2.5 min

ESCR

ASTM D1693

No cracking after 96 h in 10% Igepal at 50 ± 1 °C

Ovality on coil

ASTM F2160

< 7%

Tensile strength

ASTM F2160 (Specimen Type IV per ASTM D638)

≥ 20 N/mm²

Elongation at break

ASTM F2160

≥ 400%

Impact performance

ASTM F2160 (per ASTM D2444, Type B tup 9.1 kg)

No failure when impacted at centre from 1.5 m after conditioning at −20 °C for ≥ 1 h

Hydrostatic strength

ISO 1167

No swelling, leakage or burst for 165 h at 3.5 MPa, 80 °C

Carbon black content (outer sheath)

ISO 4427-2

2.5% ± 0.5%

Carbon black dispersion

ISO 4427-2

Uniform dispersion as per standard

Thermal reversion

As per specification

≤ 3%

Internal coefficient of friction

As per specification

< 0.6

Identification marking

As per approved print line

Ink jet high contrast print with brand, size 40/33, colour stripe, lot date; metre marks at 1 m intervals

To support safe storage, quicker laying and cleaner installations, Natraj PLB Duct Pipes can be supplied with essential accessories as per project requirement.

Push Fit Couplers

Precision couplers designed to align the duct bore accurately and ensure a secure joint. Provided with sealing O ring and locking ring for reliable connection. Typically supplied with coils unless specified otherwise.

End Caps / Sealing Plugs

Used to seal duct ends before and after installation to prevent entry of dust, water, mud and debris, helping maintain a clean bore for smooth cable pulling, blowing or jetting.

Warning Tape

Used in backfill to identify the duct route and alert excavation teams during future digging, reducing the risk of accidental damage.

Pulling Rope / Jetting Leader

Helps in cable hauling setups and blowing or jetting preparation, supporting faster installation and better site handling.

  • Socket and Spigot Jointing
  • Push Fit Couplers
  • Mechanical Couplings