Averaging & Cooling Pits

Application

Commercial laundromats and on-premises laundries where discharge temperature exceeds the trade waste limit

Hot water entering the tank passes through a removable lint basket. The tank is sized to retain water long enough that its contents cool to an acceptable temperature before discharge to the sewer.

Many Australian trade waste rules limit discharge to around 38–40°C at the treatment plant inlet. Sydney Water’s limit is 38°C. Commercial laundry effluent typically leaves the machines at 38–45°C, and industrial laundries disinfecting linen can run far hotter, so an averaging and cooling pit is often required alongside the lint trap rather than instead of it.

Viking also supplies straining tanks. Talk to the technical team about combining a cooling pit with a NP44AG or NP46AG lint trap.

VP15AG Above Ground, Thin Skin

Internal tank dimensions. Pipe sizes unless otherwise requested: inlet 100 mm, outlet 100 mm, vent 100 mm. Tanks larger than 300 L are fitted with external steel support frames — add 40 mm to all sides.

VP15BG Below Ground, Thin Skin

Internal tank dimensions. The tank has a 50 mm flat-rim flange and external keying strips. Tanks installed below ground must be surrounded with concrete — trade waste guidelines require a minimum 100 mm thickness to walls and base. The tank must be supported internally to prevent the walls collapsing while concrete is poured. Covers can be supplied.

VPT15AG Above Ground, Paneltim

External tank dimensions, not including the lid. Pipe sizes unless otherwise requested: inlet 100 mm, outlet 100 mm, vent 100 mm. Above-ground tanks are fitted with an air-tight lid with a screw-in removable cover. Tanks installed externally should be protected from direct sunlight.

VPT15BG Below Ground, Paneltim

Pipe sizes unless otherwise requested: inlet 100 mm, outlet 100 mm, vent 100 mm. Paneltim® tanks installed below ground may be surrounded with crushed rock and/or stabilised sand only. Installation must comply with the Viking Below Ground Paneltim® Tank Installation Guidelines. Tank widths greater than 900 mm may require covers with support beams, price on application. Covers for below-ground tanks are supplied separately.

Trade Waste Compliance

Water authority requirements for averaging and cooling pits generally call for a pit that:

• is designed to promote mixing of wastewater without any bypass before discharge, with the mixing effect explained in the product manual;
• has an inspectable surge baffle providing a stilling zone at the inlet, to prevent turbulence in the tank;
• has an inspectable double baffle to trap contaminants by gravity separation based on their densities;
• has an adequate opening so the device can be safely and effectively cleaned during regular maintenance;
• has a DN 100 mm vent pipe provision to assist with cooling the water within the pit.

Two further requirements apply specifically to concrete cooling pits: those used for boiler blowdown must not contain steel reinforcement or components, because of corrosion and loss of structural integrity over the tank’s life; and interior surfaces must be coated with high-temperature resistant coatings carrying a minimum five year warranty. Viking’s pits are fabricated from polypropylene and Paneltim® rather than concrete.

Requirements vary between authorities and change over time. Confirm the current standard with your local water authority before submitting, and obtain prior trade waste approval.

Related Products

NP44AG Lint Trap — the compact model, for up to three machines.
NP46AG Lint Trap — for machine banks of three to five or more units.
Lint Trap Sizing Guide — machine count, temperature and load profile.

Contact Viking Plastics today for custom solutions and Australia-wide delivery. For further information you can request a quote, or call Viking Plastics on 1800 143 143.

Viking Plastics Averaging & Cooling Pits are an Australian Made Product