Lids, Seats & Slabs (click on underlined link to navigate to one page brochure of lid of choice)
Six types of concrete lid are discussed here, all having extremely robust locking mechanisms:
1. Screw lid - A custom tool is inserted into an access tube and turned to screw the lid out of the seat. The lid is now turned through 90 degrees, the tool is partially withdrawn, and the lid is rolled away on tracks. Suitable for large heavy lids in reservoirs, valve-chambers, etc.
2. Slab-top hand lid - A custom tool is inserted into the access hole and used to unlock two opposite rack-levers below. The lid may now be lifted out of the slab by the tool's handle. Suitable for small manholes in valve chambers or reservoirs.
3. Seat & hand lid - Same opening sequence as above. The relatively small lid fits into a seat which is large enough to cover a relatively large manhole. The seat is also removeable if required. Suitable for valve chambers that have relatively large (steel) lids that have been vandalised.
4. Roof-slab & hand lid - Same opening sequence as above. The relatively small lid fits into a roof-slab that is large enough to span the full with/length of the valve chamber. Suitable for valve chambers.
5. Sliding lid - An custom tool is inserted into the access tube, and turned by the handle. The rack-lever retracts out of an anchor-cavity. The lid may be pushed open with relative ease. Suitable for valve chambers where a large opening is required for servicing the valves etc.
6. Roll-open lid - Suitable for relatively large manholes in valve chambers where quick and easy access is required, and where the opened lid must be clear of the manhole. Once the custom tool has unlocked the lid as in point 2, the lid may be rotated through 90 degrees
1. Screw lid - A custom tool is inserted into an access tube and turned to screw the lid out of the seat. The lid is now turned through 90 degrees, the tool is partially withdrawn, and the lid is rolled away on tracks. Suitable for large heavy lids in reservoirs, valve-chambers, etc.
2. Slab-top hand lid - A custom tool is inserted into the access hole and used to unlock two opposite rack-levers below. The lid may now be lifted out of the slab by the tool's handle. Suitable for small manholes in valve chambers or reservoirs.
3. Seat & hand lid - Same opening sequence as above. The relatively small lid fits into a seat which is large enough to cover a relatively large manhole. The seat is also removeable if required. Suitable for valve chambers that have relatively large (steel) lids that have been vandalised.
4. Roof-slab & hand lid - Same opening sequence as above. The relatively small lid fits into a roof-slab that is large enough to span the full with/length of the valve chamber. Suitable for valve chambers.
5. Sliding lid - An custom tool is inserted into the access tube, and turned by the handle. The rack-lever retracts out of an anchor-cavity. The lid may be pushed open with relative ease. Suitable for valve chambers where a large opening is required for servicing the valves etc.
6. Roll-open lid - Suitable for relatively large manholes in valve chambers where quick and easy access is required, and where the opened lid must be clear of the manhole. Once the custom tool has unlocked the lid as in point 2, the lid may be rotated through 90 degrees