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Underground Drainage

In this section you will find:

Concrete Drainage 

Keyline offers an extensive range of precast flexible jointed pipes from DN 300 to DN 2400, including bends, junctions and shorter lengths for rocker and butt pipes. Pipes are supplied with various jointing options, dependent upon contractors’ needs and manufacturers’ production processes.
Contractors should refer to our manufacturers’ installation recommendations, in addition to relevant regulations, as there are lifting and handling systems and specific jointing procedures available. 
Products are available to meet all classes of potential sulphate attack. Concrete pipes are vertically cast using vibration to compact a semi-dry concrete mix into the mould. Pipes are manufactured to BS EN 1916 and Kitemarked accordingly.

Lock Lift Anchor System

Pipes from DN1350 should be handled using our purpose designed Anchor System. Special lifting Anchors can be cast into pipes during manufacture. A Universal Head Link can then be hooked onto the exposed anchor heads to lift the pipe. Use the equal lengths (1 & 2) for lifting the pipe. Join the longer chain (3) onto the pipe already laid and place the shorter length (2) onto the hook. The pipe can then be jointed without moving the jib of the crane.

Manhole Rings

Concrete Manhole Chambers

Precast concrete manholes made to BS EN 5911-3 and BS EN 1917 are available in DN 900 – 3000 with metric depths of 1000, 750, 500 and 250mm, all with tongue and groove joints. They are available plain or perforated with the option of mild or stainless steel plastic encapsulated double steps, or without steps for use with ladders or winches. 
A wide variety of cover slabs and cover frame adjusting units with either standard access or special access is available. Designers and users should take into account current requirements for manhole access as detailed in the Health and Safety Code of Practice Regulations and Guidance issued by the Health & Safety Executive under the Confined Spaces Regulations 1997 and other relevant requirements.

Manhole Cover Slabs

Easi-Safe Fall Arrest System: Award Winning Safety Solution For Manhole Construction.

The client, consultant engineer, contractors and suppliers all have a duty to mitigate hazards on site whenever reasonably practicable. One such hazard identified is the risk of operatives falling through manhole openings particularly during the construction process and also in follow up maintenance work. Working with partners Severn Trent Water, engineer Grontmij and contractor to the water sector, Morgan Sindall plc, FP McCann have designed a safety award winning solution. Easi-Safe is a temporary or permanent fall arrest system that allows for safe working around the manhole opening prior to the fitting of the ironwork. In the construction of a manhole, operatives often work unprotected from the opening at surface level when the final stages of completion occur. This includes the final brickwork up to the manhole frame and the mortar bedding of the frame itself.

Manhole Solutions 

FP MCCann – Easi-Base
A prefabricated manhole base unit with integral benching, channels and connectors that provides an immediate and long lasting watertight solution in the management of waste water. 

CPM – Perfect Manhole Systems and Bases
After an extensive research programme, CPM introduced the 1200mm Perfect Manhole system in October 2009 to meet the challenges of modern day construction. Today it is available in 1200mm, 1500mm and 1800mm diameters and comprises of a monolithic precast concrete base (available pre-benched in any configuration within just days of requisition), a sealed chamber ring (with thicker walls than a standard CPM chamber ring), a rubber joint and a sealed cover slab which is supplied with your required access. Other diameters are available upon request. The Perfect Manhole complies with BS EN 1917:2002 and BS5911-3 and meets with WRC Approval and is accepted for use by all major UK companies.

Wide Wall Manhole Chamber
A 130mm thick Wide Wall Manhole Chamber in combination with the Easi Base unit, provides a sealed watertight manhole system. No concrete back fill required in accordance with Sewers for Adoption 7 (2012).

Stanton Bonna – Perfect Manhole Systems and Bases
The Perfect Manhole System is a precast off-site solution which enables contractors to install a modular watertight manhole in a fraction of the time of a traditional build, without the need for a concrete surround. The unique system comprises a monolithic precast watertight concrete base prebenched to any inlet/outlet configuration together with thick walled chamber rings with watertight joints incorporating an elastometric gasket and a sealed cover slab. The system also incorporates push fit elastometric seals for inlet and outlet pipes. Specifiers, designers and contractors can be assured that the Perfect Manhole System offers a safer, faster, sustainable, precast off-site and bespoke manhole solution.

Pipe Lining 

Pipe Doctor available from Keyline is the market leader in no-dig patch repair and is the first WRc approved patch repair system in the UK.

The Pipe lining is cost effective and low disruption, with an efficient working time, unique kit format, with a waste-free pre-measured resin bag, a WRc Approved (no. PT/318/0311) core range, excellent bonding to virtually all pipe materials and meets requirements outlined in WRc’s ‘Drain Repair Book’.


Precast Concrete Headwalls provide an ideal end connection point to outfall pipes into open watercourses such as rivers, culverts and collection and balancing ponds. They are a very efficient alternative to intrusive shuttering of soil embankments and costly on-site formwork with ready mixed concrete making them particularly suitable for use in hard to reach locations and in environmentally sensitive areas. 
Where time constraints exist such as in tidal flow situations, concrete headwalls can be quickly positioned, secured and backfilled, providing immediate stability around the point of water discharge. Standard headwalls can accommodate pipe sizes from DN150 to DN900 and with the recent addition of the extra large twopiece unit, pipe sizes up to DN1500 can be connected. Additionally, accessories such as flap valves, penstocks, silt traps, handrails and safety grating, can be built in as part of the specification. A front weir wall can be fabricated onto any of the standard headwall range on request.

Precast Special 

The Hydro StormTrain™ Series of Surface Water Treatment Devices

Hydro StormTrain™ Series from Hydro International is a comprehensive toolbox of surface water treatment devices. The Hydro StormTrain™ Series provides an unrivalled range of performance-verified and internationally recognised technologies to meet current and expected water quality regulations in the UK. Four products: First Defense®, Downstream Defender®, Up-Flo™ Filter and Hydro Filterra™, are Sustainable Drainage Systems (SuDS) that can be used independently or in combination to deliver a Treatment Train that meets the water quality requirements for most sites. They can also be used to protect, enhance or enable natural SuDS features.

Flow Control Units

The vortex flow control is a self-activating flow control device which induces a vortex motion in the flow to control the rate at which water is allowed to enter downstream drainage systems. The energy inherent in the water flow is harnessed to generate the vortex and hence has no need of external energy requirements. The flow control itself has no moving parts. The VFC has a superior hydraulic performance when compared to conventional flow controls such as orifice plates, throttle pipes and penstocks. With outlet diameters up to 400% larger than conventional flow control devices, the risk of blockage is minimised. VFCs have a unique head/flow characteristic with a distinctive “S” shaped curve with high flush and kick-back flow points. This characteristic can reduce storage volume requirements thereby lowering project costs.

Precast CSOs (Combined Sewer Overflow)

In areas where combined sewers (storm and foul) are used, excessive water flows can create unsatisfactory intermittent discharges (UIDs). Under European legislation water authorities are required to reduce the pollution created by UIDs. The use of CSOs reduces the hydraulic loading on the treatment plant by diverting excess flows to appropriate alternative drains.Keyline Utilities can offer solutions for most applications, reducing the need for wet trades on site, reducing the installation time and reducing the overall cost of the project whilst offering factory made product quality.


Key Benefits:

  • Full range of pipes and fittings from 100 to 600mm
  • Incorporates recycled plastic
  • BBA Approved
  • Longer lengths so fewer joints for improved resilience to leakage
  • Structured wall design for high ring stiffness and strength
  • Lower weight for reduced transport/installation costs and improved Health and Safety benefits
  • Reduced CO2 consumption in production, transportation and on-site handling up to 94% lighter than concrete means fewer delivered to site
  • Withstands ground movement and differential settlement
  • Extremely smooth bore so less likely to block and more easily maintained
  • Integral sockets in diameters 150-600mm for ease of installation – greater joint integrity Interceptors and Separators

Linear Drainage

This drainage system is suitable for a wide range of civilsapplications. Products include an extensive ACO range. Certified to BS EN 1433:2002 D 400.

  • Available in 100, 150 and 200mm channel widths and a range of depths to suit many different catchment areas
  • Manufactured from Vienite® recycled polymer concrete with UltraSTEEL™ protective edge rails
  • Wide choice of grating styles available to cater for many different pedestrian and vehicular trafficked applications
  • Gratings fitted with ACO Drainlock™ – a bar-less locking device which reduces the risk of blockages
  • Corrosion resistant stainless steel channel and grating options available
  • Off-set brickslot galvanised and stainless steel grating available for discreet slot drainage applications
  • Suitable for commercial and residential developments, pedestrian precincts, landscaping and parking areas for all vehicle types.*

 *This system is not suitable for carriageways of public roads or motorways.


For more information Download a PDF of the Underground Drainage section of our Utilities guide here.