Solenoid valves - Bürkert Fluid Control Systems

7.1.
Safety valve for burner
control
Field of application
Safety valves are fitted in the supply or
return of the oil line for use in oil burner
installations.
Design
Two versions of safety valve are mounted
on the block.
Use as supply valve: the valve is normally
open and is tight up to 30 bar.
Use as return valve: the valve is normally
closed and is tight up to 30 bar
in the direction of the safety shut-off.
At the same time, the valve operates
as a check valve and opens starting
with a pressure of 0.15 bar in the return
direction.
If a burner or installation is switched
off, the return valve operates as a
check valve (spring-controlled). Oil
which is not used flows unhindered
back into the tank. The supply valve
shuts off in the safety shut-off (both
valves are energized). No oil is routed
to the burner and the oil in the line at
the burner end is discharged via the
return valve.
Characteristics
■ Body material: brass, stainless steel
■ Seal material: brass, stainless steel
■ Seal material: FPM, PTFE, graphite
■ Media: neutral gases and fluids;
oils and hydraulic fluids
■ Media temperature: 10 to +140 °C
■ Ambient temperature: max. +55 °C
■ Operating voltage: 110 V, 50 Hz
■ Voltage tolerance: ±10%
■ Duty cycle: continuous operation
■ Electrical connection: tag connectors
in accordance with DIN 43
650 A for Type 2508 appliance
plug socket
■ Installation position: any position,
preferably actuator pointing upwards
■ Type of protection: IP 65 with
appliance plug socket
■ Upstream filter: the use of the valves
is allowed only with upstream
strainer (mesh aperture less than
0.5 mm)
Supply valves
P U
Burner
Tank
Return flow
Return valves
Components/Function Quantity Typical parameters
Supply valve 1 2/2-way valve ; WW B (normally open)
DN 13 mm, flow rate = 2.0 m 3 /h
Pressure range = 1 to 30 bar; back-pressure 1 bar
Return valve 1 2/2-way valve; WW A (normally closed)
DN 13 mm, flow rate = 2.0 m 3 /h
Pressure range = 1 to 30 bar; back-pressure 1 bar