English to Greek Tech/Engineering Mechanics / Mech Engineering

The oil level indicator also has a minimum and maximum level switch.
The indicator bar contains two types of rollers:
Red: full;
White: empty.
The tracing is used when thick oil or fat is stored.
The tracing warms the piping and prevents oil or fat to thicken in the indicator.
Extra connection fresh oil supply
An extra connection can be installed to supply fresh oil to the tank.
A free contact is installed to fill the oil tank with fresh oil.
Tracing on piping
Tracing warms the piping and prevents oil to thicken.