Multiple hinged steel cover installation guide

The covers and frame need to be lifted as one unit and placed centrally over the chamber's clear opening. Local spacers should be used below the frame to set the top of the assembly to the finished floor level. If the finish is too deep for a mortar bed use courses of engineering brickwork to raise the frame, the base of the frame needs to be fully supported.

Unlock the covers (see separate data sheet for the operation of turn catch ‘lock-lift’ devices if fitted) and retain any removable locking screws for replacement later.

Open the covers ensuring that the safety stay bars are fully engaged in the open position.

The demountable safety barriers and fall protection grids are optional factory-fitted extras and are not supplied as standard, these items cannot be retrofitted.

Note: Assisted lift products may have the spring pre-tension reduced for safety during transport and handling, be aware that this considerably increases the opening weight of the covers at the installation stage, once fully installed the springs can be reversed to activate. Covers supplied in this condition will be labelled accordingly on the underside of the lid.

Check the position of the frame in the rebate or on the cover slab, ensuring that the clear opening of the frame aligns with the chamber opening. Note that overhanging, unsupported framework can cause premature cover failure.

The top edge of the frame needs to be set level and at the correct finished floor height, use hard shim material between the frame and the cover slab to achieve this.

Also ensure that the frame is square and that all sides are straight, space and pack if required, close the covers as necessary to check the fit during this operation.

When in the open position the cover sides should be vertical and not interfere or collide with adjacent lids, all covers should close and open independently, unless intentionally interlocked for sequential opening. Colliding covers (open or closed) indicates that the hinged side of the frame is out of true and must be adjusted.

Close the covers as a trial fit, ensure that the covers do not rock and that they sit neatly with even gaps around the frame and adjacent covers, making any necessary adjustments to the frame to achieve this.

Check engagement of the cover locks but do not overtighten, covers should sit flat without excessive clamping from the locks.

Note: It is critical to achieve a good fit at this stage, it cannot be improved once the frame is cast in. Do not cast the frame in position without checking the operation of the covers and locks.

Secure the frame in position using M12 anchors through the 13 mm diameter holes provided in the frame flange or fixing lug. Do not overtighten as this can distort the frame.

The base of the frame must be fully supported on a mortar bed either by hand packing or pourable grout.

The outside of the frame should be encased in mortar either within the rebate or cast into the floor slab.

Once the frame is secure the fabricated pockets supporting the cross beams need to be fixed to the chamber wall with M12 anchor bolts, and shim any gaps between the pocket and the chamber wall to avoid distortion of the frame.

Clear any debris and loose material from inside the frame and cross beams.

Grease the cover locks or removable locking bolts before finally closing the covers.

Care should be taken when removing and handling beams as weights can be in excess of 40kg per metre.

If the beams are fixed in place, remove the bolts, nuts, and washers, and retain them for replacement later.

Remove the shorter transverse beam first, followed by the longer main beams (beams that are bolted to the frame should be identified / marked to ensure that they are returned to their original locations).

For safety reasons springs on some covers may have been disabled, removing pre-tension from the frame during transport and installation.

Be aware that covers in this condition may not be suitable for one man lift until fully installed and the springs reactivated.

In the case of shallow frames, where the spring retaining brackets protrude below the base of the frame, support must be provided by the chamber wall, add packing between the bracket and chamber if necessary.

Failure to provide proper support for the bracket will allow it to flex, resulting in loss of spring tension and increased cover lifting weights.

1. Open the cover ensuring the stay bar is fully engaged.
2. Remove the spring retaining bolt & nut or pin & D clip.
3. Rotate the springs through 180°.
4. Replace the spring retaining pin.
5. Close and lock the cover.

Spring in deactivated (transport) position

Springs in working position