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Unite™ D400 manhole covers

Simply the best D400 access cover range available in the market, in fact it's so good Unite is available with a 10 year warranty*. Packed full of design features that combine to give Unite the longest life and lowest whole life cost of any D400 access cover available. Designed and manufactured to exceed BS EN 124 and Highways England’s Design Manual for Roads and bridges (DMRB) specification CD 534 v0.1.0.

Unite D400

Over the course of 40 years we have a deep understanding of pavement and highway ironwork performance. Using the very latest tools and software, the Unite range of manhole covers have been engineered for extremely long life.

Key to Unite’s longevity is minimising seat wear between covers and frames. The range has the stiffest cover structure in its class and on top of this, seating which is less vulnerable to any movement caused by cover flexing which may take place. We're so confident in Unite's performance, it's available with a 10 year warranty*.

Unite has been designed to work sympathetically with bedding mortars, reducing stresses on the frame foundation, which has been identified by WRC as a major cause of manhole cover failure.

    BS EN 124, CD 534 v0.1.0, Kitemark


    Engineered for an exceptionally long life:

    • Available with a 10 year warranty*
    • In service on highways for over 20 years
    • Over 500,000 installations with zero reported failures
    • Unique cover design substantially reduces seat wear
    • Frame features that are sympathetic to bedding materials
    • Exceeds BS EN 124-2:2015
    • Complies with DMRB, CD 534 v0.1.0 (formerly HA 104/09) and Series 500
    • Kitemarked by BSI 100% recyclable product

    Square and rectangular manhole covers

    Stock code Range Clear opening
    (mm)
    Overall frame
    (mm)
    Frame depth
    (mm)
    Options My Wrekin
    DMT0D4/6060/KU Unite 600 x 600 810 x 810 110
    DMT0D4/6767/KU Unite 675 x 675 885 x 885 110
    DMT0D6/6767/KU Unite 675 x 675 885 x 885 150
    DMT0D6/1267/KU Unite 1,220 x 675 1,465 x 920 150
    DMT0D6/1867/KU Unite 1,830 x 675 2,075 x 920 150
    DMT0D6/6060/KUE Unite 600 x 600 820 x 820 150
    Unite 10 year warranty

    Unite 10 year warranty

    When installed with either our Unipak polymer resin bedding mortar, or Instarmac Envirobed® CD534 flowable bedding mortar, the Unite range is available with a 10-year product warranty*.

    Due to its unique design and overwhelming success in the local authority and utilities sector, Unite is the proven choice for durability and longevity for highway ironwork installations.

    View further warranty information

    * Subject to terms and conditions

    Packed full of features

    • 70+ PSRV tested at top surface of chequer by UKAS accredited 3rd party.

      PSRV tested
    • GritBlocker™ anti-blockage keyway insert comes pre-installed.

      Anti-blockage keyway
    • The covers feature a universal beam (also known as an I beam) providing significant improvements to rigidity, reducing seat wear for an enhanced service life.

      Universal beam icon
    • The high seating position ensures that forces are transmitted more directly downwards, meaning conversion of traffic loads into mortar-compatible compression forces.

      Cover support geometry
    • Surface texturing above and below the flange enables better mortar engagement, reducing any lateral movement which could result in cracking.

      Textured mortar engagement flange surface
    • The enlarged frame corners help to dissipate loads onto the foundation, providing a longer service life and increased reliability.

      Enlarged frame corners
    • Mechanical lifting points are provided.

      Mechanical lifting point
    • Safety keyway prevents accidental disengagement of the lifting key during the handling process.

      Safety keyway
    • Meets the requirements of CD 534 v0.1.0 (formerly HA 104/09).

      CD534 v0.1.0
    • Unite is available with a 10 year warranty (subject to terms).

      Unite 10 year warranty
    • Keyway lifting points are provided on the frame for safe handling.

      Keyway lifting point in the frame
    Unite manhole cover installed in Piccadilly Circus

    Should I upgrade to an E600 cover?

    There are several advantages, and reasons driven by standards, to increase the load classification of an access cover from D400 to E600, including:

    Increased frame bedding area

    E600 covers feature an increased frame bedding area, this results in a reduction in bedding stresses during trafficking, increasing the longevity of the product and its installation.

    Increased resistance to unintended traffic

    E600 products are more likely to be resistant to unintended traffic loads e.g. pre-service loads as commonly found on construction sites which can result in damage to installed ironwork.

    AADT >1,500?

    National Highways CD 534 stipulates where the Annual Average Daily Traffic (AADT) of light goods vehicles travelled on a road is greater than 1,500 in each direction, an E600 cover must be installed. Most A roads will have an AADT above this.

    Read more about CD 534
    Unite D400 manhole cover showing mortar gripping feature
    Mortar ‘gripper’ system

    Effectively interlocked with bedding material

    Unites flange surface provides a textured finish for bedding mortar to adhere to and the holes allow for interlocking between both sides. This will enable Unite to utilise the mechanical properties of bedding mortar, not just its adhesive characteristics.

    The built-in bevelled frame edge as standard, prevents sharp edges from cutting into and breaking mortar away over time, as vibrations from traffic are transferred into the foundation.

    These unique, mortar-sympathetic, and advanced design features, allow Unite installations to stand the test of time in extreme environments.

    Unite D400 manhole cover with a large cover seat area
    Large cover seating area

    Increase your asset life

    Cover seating wear has been attributed as a major reason for failed manhole covers, which can lead to rocking, unwanted noise and eventually, failure.

    To further increase the lifespan of our Unite range, we have included a larger cover seating area. This increases the resistance to general wear by providing a large interface between covers and frames.

    In addition, we seat our covers as high up the frame as possible. This minimises frame movement, which otherwise would be transferred through the frame to the flange and bedding mortar, causing premature failures.

    A locking bolt entered into a Unite D400 manhole cover
    Locking bolt provision

    Provide controlled access

    Our Unite range can improve site security and provide security from theft and malicious damage or unauthorised access, with the addition of a factory-fitted locking bolt.

    In order to provide controlled access, Unite access covers can be supplied with robust factory-fitted screw fasteners. A specifically formed recess is provided for this purpose.

    Exploded render of Unite D400 manhole cover showing Internal accessory receiver
    Flood and odour control

    Retrofittable sealing plates

    Unite manhole covers are fully compatible with our range or no leak and low leak sealing plates, thanks to the built-in internal accessory receiver. This internal skirt is provides a sealing face to mate with different specifications of seal plate, depending on the application requirements (only available on products with reference ending in "/KUE").

    This simple solution provides easy, effective and adaptable flood and odour control to access chambers, and does not need to be specified at point of order, unlike nearly flood and odour plate alternatives.

    Retrofittable identification bolt being installed in a Unite access cover
    Only with Wrekin

    Retrofittable badging and antenna options

    Unite* and Highway access covers are the only ranges on the UK market to include provisions for communications equipment, such as antennas, to be installed within the cover.

    Antenna in cover linked to hardware in chamber

    The ID bolt provision can be used for antennas, allowing communications equipment, such as water meter monitoring, to be installed within a chamber beneath a cover whilevproviding a strong signal above ground without the need to dig or adjust the surrounding road surface. Saving significant time, effort and money while minimising disruption.

    * references ending /KUE

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    Whether you are looking for live project support, or are in the initial stages of specification, we are always on hand and happy to help.