National Oilheat Research Alliance 35
Thermal relief valves
When fuel is trapped within a closed section
of fuel line (such as between a check valve
and a fuel unit or solenoid valve) and the fuel
temperature rises, the thermal expansion can
cause dramatic pressure rise which can damage
heating equipment. This can easily occur when
the fuel is stored outside, either above or below
ground. Anytime a check valve is installed in
a fuel line, a thermal relief valve should be
installed to avoid leaks in fittings and damage
to equipment.
For more information see: earthsafe.com/LPThermal
Expansion-In-Fuel-Oil-Piping
Diagram shows installation of a
TigerLoopTM de-aerator, designed
to remove air and gas bubbles from
the fuel line