WWP Landing

Explanation of Wastewater Pressure Pipe Types & Materials

PIPE TYPES 

M90SE is a black PE100 RC pipe with external twin stripes to identify the pipes application (Pressure Sewer or Stormwater) and light coloured internal layer to assist with CCTV inspection.  The three elements of the pipe CCTV pipe are co-extruded to BS EN 12210-2, using PE100 RC compounds complying to BS EN 12201-1.  The three elements of a CCTV pipe are the inner orange layer, identification stripes and the black pipe body.  These produce a single homogeneous pipe, meaning the colour layer and stripes cannot be separated in any way once the pipe is extruded.  M90SE pipe is supplied in sizes from DN100 (110mm OD) to DN 1350 (1600mm OD) using PE100 RC compounds as standard.  PE100+ compounds (Non RC pipe) is only supplied if specially ordered as M90S pipe.

CCTV PIPE has an inner light orange colour layer (See Fig. 2 - RAL 2003 in granule form) which is 15% of the pipes wall thickness.  Orange PE100 RC pipe grade material is typically used for the manufacturer of Gas pipes and it is supplied pre-coloured, ready to extrude by the compound manufacturer.  DSD Appendix Clause 3.1 states compounds may not be pigmented or coloured by the pipe manufacturer. Factory pigmented compounds or using different grades or brands of PE presents a risk of incompatibility during extrusion, typically delamination of the layers, leading to structural wall failure in the pipe and ultimately premature pipe failure.

CCTV Colour layer - Because the Orange thickness is specified at 15% of the pipes wall thickness, the colour of the inner CCTV lining varies according to the diameter of the pipe.  In small pipes DN100 (110 OD), the Orange colour is approx 1.0mm thick, it is more translucent against the black compound and appears lighter (more yellow) in colour. As the pipe size increases, the orange layer becomes thicker, translucency reduces, until it is bright orange. Full orange colour occurs in sizes of approximately DN300 (See Fig.1 below).  

This variation in colour is perfectly normal, it has no impact on CCTV inspections and demonstrates the manufacturer is correctly using a PE100 RC gas compound to make the CCTV layer. If the orange inner layer does not exhibit these characteristics, this indicates the pipe maker has likely used pigments to manufacture the CCTV inner layer on line, rather than using a certified PE100 RC Orange Gas Compound required in DSD Appendix 5A, Clause 3.3. Use of Pigmented colours poses a significant risk of delamination and pipe wall failures in the future. (See Fig.3 below, an example of pigmented pipe supplied to Hong Kong)

STRIPES are used to identify the pipes application (Pressure or Drainage, Sewer or Stormwater).  The Hong Kong Drainage Services Department (DSD) uses the European colour coding system:

  • Red Brown (RAL 8012) - indicates Sewerage use (See Fig.4 below)
  • Fern Green (RAL 6025)- indicates Stormwater use (See Fig.5 below)
  • Single stripes around the circumference of the pipe - indicate gravity drainage (non-pressure)
  • Pairs of stripes around the circumference of the pipe - indicate rising main (pressure)

Mill-Pro manufacturers our own stripe compound using a certified non-pigmented (clear) PE100 RC compound and engaging a third party compounder to pigment the compound to RAL 8012 Red-Brown and RAL 6025 Fern-Green.  Our pipe manufacturer uses this certified PE100 RC compound to stripe the pipe. This process, whilst more time consuming, ensures that the stripes are 100% compatible with the rest of the pipe body and there is no possibility of stripes peeling off the surface of the pipe. 'Stripe delamination' can lead to leaking at the joints, through electrofusion couplers.

Refer here for a case of delaminating stripe coupler leakage and the associated contract delays and legal battles over the repair costs.

M100 / M100S-Pipe is a 100% solid black wall pipe (no CCTV inner layer), the pipe is extruded from a single PE100 RC compound for M100E or with PE100 RC co-extruded coloured stripes to identify the pipes service use for M100SE.

 

PIPE MANUFACTURING STANDARDS

All Mill-Pro pipes and fittings are manufactured in accordance with:

BS EN 12201-1 for Compounds,

BS EN 12201-2 for Pressure pipes

BS EN 12201-3 for Pressure fittings

Drainage Services Department Particular Specification Appendix 5A

Mill-Pro Pipes and fittings also generally comply with ISO 4427-1/2 and AS/NZS 4130 for pipe, AS/NZS 4131 for PE Compounds, although are not marked as such.

 

PIPE COMPOUNDS

M90S / M100S Pipes are manufactured from a PE100+ association approved compound www.pe100plus.com providing 1000 hrs slow crack growth performance.  Since 2007 PE100+ compounds have been progressively superseded by PE100 RC (Resistant to Crack) compounds, which provide far superior performance and life. Mill-Pro only supplies M90S / M100S pipes by special order.

M90SE / M100SE Extreme Pipes are manufactured ONLY using PE100 RC compounds for the pipe body, the CCTV layer and the stripes.  PE100 RC compounds provide approximately 8 x greater slow crack growth resistance when compared to traditional PE100+ Compounds, for a negligible extra cost. All pipes supplied by Mill-Pro in Hong Kong are PE100 RC (M90SE / M100SE).

PE100 RC (Resistant to Crack) sometimes known as Extreme Stress Crack Resistant (ESCR) or High-Stress Crack Resistant (HSCR) compounds, are defined in the German publicly available standard: PAS 1075:2009-04. PE100 RC compounds are designed to provide lifelong resistance (>100 years) to traditional Slow Crack Growth (SCG) failures caused by rock impingement and point loading stress.

Designed for applications all commonly found in Hong Kong: Where sand bedding around the pipe is not used, where backfill material is ungraded and typically contains broken concrete or where secondary excavation (repeated excavation alongside the PE pipe, to access other services in close proximity) leaves the PE pipes without the required bedding around the pipe to prevent rocks or concrete point loading on the pipe surface.

Read more about PE100RC compounds or refer to the Borouge website on Borsafe™ HE3490-LS-H here.

Global PE100 RC compound manufacturers – updated as at Q4 2019

Mill-Pro uses only 100% virgin, Pre-Pigmented and Pre-Compounded raw materials, complying to BS EN 12201-1 for its pipe and fitting products.

Mill-Pro does not manufacture PE 80 pipe or use any recycled materials in the manufacture of any of our products, although our products are 100% end of life recyclable.

Mill-Pro E (Extreme) pipes are manufactured using only 100% virgin PE100 RC compounds. CCTV inner colour, black pipe body and all striping materials are all pre pigmented, certified PE100 RC compounds.

Some manufacturers use non-compliant linear low-density striping compounds during pipe manufacture. These are not PE100 RC compounds.  Incompatibility with the PE100 RC and couplers can lead to leaking along the stripe path when the pipes are joined using electrofusion couplers. Refer here for more information on these risks.

Manufacturer

Compound Model / Datasheet

Colour

RAL Colour Certification

Borealis

Borsafe HE3490LS-H

Black

RAL 9011

Borealis

Borsafe HE3492LS-H

Orange

RAL 2003

Borealis

Borsafe HE3497LS-H

Red Brown

RAL 8012

Borouge

Borsafe HE3490LS-H

Black

RAL 9011

Borouge

Borsafe HE3492LS-H

Orange

RAL 2003

Sabic

P6006RC Black

Black

-

Total

XSC50 Orange

Orange

-

LyondellBasell

Hostalen CRP100 RESIST CR Black

Black

-

LyondellBasell

Hostalen CRP100 RESIST CR Orange

Orange

-

Ineos

Eltex TUB 121N6000

Black

-

Ineos

Eltex TUB 125N6000

Orange

-

Qenos

Alkadyne HCR193B

Black

-