Installation
- Outside installations must be a minimum of 50mm above ground level to exclude stormwater.
- Chequerplate covers can be fitted with recessed drop handles and/or frame to suit brick paved areas.
- Cast iron covers can be supplied.
- Epoxy coating is available upon request.
- Increments are available on request.
- Heavy duty and light duty concrete covers with cast in cast iron covers and frames are available.
- Trade waste arresters are available as either oil and grease arresters, settling pits or acid neutraliser pits.
Excavation, Base Preparation and Backfill
- Over excavate by 300mm all around to all sides for backfill.
- Base preparation shall consist of excavating flat uniform surface to a depth of 100mm below the required level and backfilling with 10-12mm gravel for bedding of the tank.
- Where natural ground is extremely soft, over excavate by 200mm, compact 100mm of 50-75mm ballast into the surface and backfill to the required level with 10-12mm gravel.
- Complete backfilling with approved granular material such as sand compacted in 150mm layers to 90% maximum dry density in accordance with AS3798.
- After installation of the tank, backfilling shall be raised evenly around the tank with a maximum backfill height differential of 400mm at any time.
Please Note: Where circular gas-tight inspection covers are fitted a minimum of 600mm vertical clearance between the underside of the cover slab and the static water level in the arrester is necessary to facilitate routine servicing.
