Use

Rainwater and yard water treatment.

The gravitational oil trap, defined by class II according to UNI EN

858-1, are setting tanks that separate mixtures with petrol, oils,

mineral fats and other light fractions of petroleum products that

are highly polluting and are not biodegradable. They are installed

in places such as parking areas, service stations, car parks, car

washes, etc. to avoid that oil-based residues flow into drains or the

environment, polluting the territory after a rainfall.

Operation

The process of oil extraction uses the principles of settling by

flotation. The oils, fats and substances that are lighter than water

are separated into a setting area, floating on the surface, while

all solid particles that are heavier than water go to settle on the

bottom of the tank. The oil trap should be selected based on the

drainage area that can be covered (covered car park) or uncovered

(uncovered square) and the maximum drainage capacity.

Maintenance

To maintain the proper operation of the plant the flowing controls

must be carried out every six months:

•

the level of the inert substances in the grease separator;

•

the level of oil/hydrocarbons in the grease separator;

If an excessive amount of sludge (inert) is found in the grease

separator, proceed to its removal.

If an excessive amount of oil/hydrocarbons are found in the

grease separator, proceed to their elimination.

COVERED AND UNCOVERED PAVED AREAS

PRIMARY TREATMENT

Specification Item

Grease separator/sand trap suitable to separate by gravity the non-

emulsified oil/hydrocarbons lighter than 0.85 g/cm

3

from the drained

wastewater through static separation with efficiency increased by

90%.

Grease separators/sand traps manufactured in rotational

polyethylene, in a single structure, free of joints and reinforcement

plating, equipped with inlet and outlet holes, and inspection and

sampling lids. Suitable for underground installation. The plant has

been designed with the following parameters:

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PROJECT PARAMETERS

Type of oil/hydrocarbons (specific weight)

Retention time in the treatment stage

Rainfall for the calculation of

absorbing surface

Fire system flow (covered areas)

g/cm

3

min

l/s m

2

l/s m

2

0.85

approx. 4

5,5 l/s x 1000m

2

2,2 l/s x 1000 m

2

Example of installation

INSPECTION

WELL

OIL