Telephone: 01229 814 340

D400 Composite Covers

Handling & Installation Removal & Replacement Guide

1. Handling & Installation

Frames and covers should only be installed using the installation and fitting guidelines below.

  1. Frame must be fully supported on a concrete base all the way around.
  2. Frame must be seated perfectly level.
  3. Frame and cover seating faces must be thoroughly cleaned before inserting the cover into the frame.


Following the correct installation guidelines will ensure a long and trouble free life for both the frame and cover.

1. To ensure frames are not installed distorted or twisted we advise the cover is placed in the frame when set on mortar and concreted in place.

2. Do not allow cement or concrete to set hard on the surface of the cover and frame during installation

1. Pour vous assurer que les cadres ne sont pas déformés ou tordus, nous vous conseillons de placer le couvercle dans le cadre lorsqu’il est fixé au mortier et bétonné.

2. Ne laissez pas le ciment ou le béton durcir à la surface du couvercle et du cadre lors de l’installation.

1. Um sicherzustellen, dass die Rahmen nicht deformiert oder verdreht installiert werden, empfehlen wir, die Abdeckung im Rahmen zu platzieren, wenn dieser in Mörtel eingelegt und betoniert wird.

2. Zement und Beton dürfen während der Installation nicht auf der Oberfläche der Abdeckung und des Rahmens hart werden.

1. Para asegurarse de que los marcos no se instalen deformados o torcidos, aconsejamos que la cubierta se coloque en el marco cuando se fije en la argamasa y se emplace en el hormigón.

2. No permita que el cemento o el hormigón se endurezcan en la superficie de la cubierta y el marco durante la instalación.

2. Cover Removal


DO NOT attempt to lift covers and dip caps with any other tooling device, this will damage the cover, seal and locking mechanism.

Evidence of a failure to use the ThuBeam Seal Breaker Lifting Tool will invalidate the product warranty.


Remove cover lock security plug.

Insert lifting tool into cover lock security plug, turn through 90° anti-clockwise, unscrew and remove. DO NOT lose security plug.


Insert seal breaker lifting tool & unlock cover.

Insert lifting tool into the keyhole and turn the handle through 90° clockwise towards you to automatically disengage the cover lock.


Release the foot plate from the seal breaker lifting tool.


Press down firmly on the foot plate to release the cover from frame.


Fold back the foot plate into the lifting tool and lift cover from frame.


Cover can now be pulled safely back away from the frame.

3. Cover Replacement

Before re-inserting the cover back in its frame, ensure the seating face of the frame and cover is clean and free of any debris or stones. Clean the frame seal with a damp cloth and wipe the inside of the frame thoroughly.


Ensure lifting tool is inserted and in the position as shown above before pushing cover.

Push cover back into frame using your foot. Keep fingers away from cover/frame edge.


Keep lifting tool inserted and in the above position whilst re-instating cover back into the frame.

Stamp cover down firmly to engage seal. DO NOT use a hammer to aid replacement.


Turn the lifting tool through 90° anti-clockwise to re-engage the cover lock and lift the tool free of the lock housing.


Clean out any debris in the lock housing, check and clean the security plug and seal before re-inserting.

Re-insert the cover lock security plug. Turn the security plug clockwise to tighten. A firm finger tight seal will be sufficient.

4. Care & Maintenance Guidelines

ThruBeam covers and frames can only perform to the highest standards if they are routinely checked and maintained in accordance with our guidelines.

Thorough cleaning of seals, frame seating face and cover edges at each lift is essential.

Damaged or missing seals and missing key housing security plugs should be immediately replaced.

We advise all cover service teams carry a full ThruBeam maintenance kit which contains all the necessary replacement components.


Routine Cleaning Procedure

The frame seating face should be brushed and cleaned every time the cover is lifted.

Cover seals and seating faces should be cleaned with a damp microfibre cloth.

Cover Seal Orientation



Cover Seal Replacement

Remove damaged seal. Inspect & clean the seal channel with a damp microfibre cloth.

More information and videos on seal fitting and replacement here.

Use a rubber faced hammer only.

Ensuring correct orientation. Taking care, ‘gently’ tap new seal into position.



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    ThruBeam ®

    Structural Science Composites Company
    Unit 8 James Freel Court
    James Freel Close, Barrow in Furness,
    UK, LA14 2NG

    Tel: +44 (0)1229 814 340

    Registered Name: Structural Science Composites Ltd.
    Company Registration: 5553133

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