Solenoid valves - Bürkert Fluid Control Systems

2.2.
Direct-acting solenoid
valves: plungers
General characteristics:
■ Rugged design
■ Good value for money
■ Universal field of application
■ Broad nominal diameter range
■ AC, DC and UC variants available
■ Friction leads to restricted service
life without lubrication
■ Restricted pressure range results
from media separation
■ On 3/2-way version, one port points
upwards
■ Circuit function B (normally open),
available for many versions
■ Also available as explosion-proof
version
■ With push-over coil.
2.2.1. 2/2-way plunger-type
solenoid valves
Direct-acting 2/2-way plunger-type
solenoid valves (e.g. Bürkert Types
6011 and 6013), also referred to as
through-way valves, are shut-off valves
with two ports: one inlet P and one
outlet A, see Figure 1: Inlet P is connected
to the pressurized fluid or gas.
In the de-energized state, the core
spring, assisted by the fluid pressure,
forces the solenoid core (plunger)
with the valve seal onto the valve seat;
passage to outlet A is thus shut-off.
If voltage is applied, the solenoid core
with the valve seal is pulled into the
coil as the result of the magnetic force
and the valve opens; the passage is
unobstructed again.
Characteristics:
■ Flow direction normally above seat
■ The maximum pressure depends
on the nominal diameter and power
consumption of the coil
■ Weak springs in use, i.e. low backpressure
tightness (dependent on
spring force and nominal diameter).
Solenoid coil
Electrical connection
Core spring
Core, plunger
Valve seal
Valve seat
P
A
Valve body
Figure 1:
Direct-acting 2/2-way plunger-type solenoid valve,
shown closed at left and open at right
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