Solenoid Valves

Technology from Bürkert, particularly solenoid valve technology, is not only encountered in industrial installations in an extremely wide variety of sectors, it can also be found literally on the street: inside many useful devices and apparatuses that make our daily life easier.

Bürkert’s solenoid range has evolved over decades. Only the fittest valves have survived the test of adding true value to our customers around the world. Some designs have already stood the test of time while some display the newest innovations. One thing is for sure … we have the right solution for your most demanding process solenoid requirement.

Direct Acting Valve Anatomy

Coil
Wrapped enamelled copper coil which concentrates the effect of the magnetic field produced when current passes
through a conductor. Available to employ alternating (AC) or direct current (DC). DC coils are quieter, show less wear on the plunger or core tube and demonstrate a high holding force whereas an AC coil, although it displays faster switching times, can hum, requiring a shading ring and facing a risk of burn-out if the plunger is ever jammed.

Plunger
A precision mass which reacts to the influence of the magnetic field created by the coil when current is added. The
plunger is held by the coil for as long as current flows. When the flow of electric current is halted the spring forces
the plunger back to its rest position. Stringent magnetization properties, low magnetic memory effect, high wear resistance as well as high chemical resistance are required.

Spring
The spring usually works against the coil to revert the valve back to its normal position when the valve sees no power.

Electrical Connection
A wide range of global electrical connections are available. Many solenoid systems are designed for IP65 protection. Core tube Accurate tube in which the plunger moves. Shading ring (Required on AC Only) An electrically conductive ring located in the stopper to prevent constant oscillation based on the mains frequency.
Without this addition noise would result from the interaction of the spring force and the magnetic force when, twice
per cycle, the voltage drops to zero and the spring wins the contest.

Air Gap and Stopper
Stringent requirements in regards to evenness, flatness and peak-to-valley height are made on the pole faces of the stopper and plunger to achieve a hum-free holding force which is as high as possible. A large air gap between the poles substantially reduces the holding force since the magnetic conductivity of air is substantially less than that of iron.

Encapsulation
Either polyamide or epoxy coating is molded around the coil to protect it from damage. The material determines the working rate of the coil. The encapsulation material and the coil surface area predict good heat dissipation and radiation from the surface. The chemically resistive encapsulation protects the electrical system against harmful influences such as dust, dirt and moisture.

Orifice
Usually measured by diameter in mm this determines the area on which the media pressure will act and the gap
through which the media will flow when the valve is energized. Bürkert deliver valves with orifice diameters from
0.05 mm to 65 mm.

Fluidic Connection
Many fluidic sizes and connections are available to meet local geographic or industry specific standards.

Seal & Seat
A seal is the soft material, connected permanently to the plunger, which halts the flow of fluid from one side of the
orifice to the other when sitting on the seat which is a raised area on the orifice which concentrates the pressure
of the seal.