Is the spool of the solenoid valve magnetic? What kind of properties are required?

The spool of a solenoid valve must not be magnetic, and this is related to the law of electromagnetic induction; when the coil is energized, it generates a magnetic field that directly moves the spool.

If the valve core is non-magnetic, it is equivalent to an iron rod; then can a charged coil push this iron rod to move? It seems it won’t work, right?

The spool of the solenoid valve contains magnetic elements to meet the requirements, but the material of the spool should depend on the application environment: different types of spools should be used in environments such as water, oil, steam, and corrosive liquids.

Whether it is an AC or DC electromagnet, the core should not be magnetic when uncharged. For DC electromagnets, low-carbon steel (soft iron) can be used for the core, while silicon steel sheets are used for AC electromagnets

The wind cooling one’s buttocks makes one think deeply; you really wouldn’t think of this question if you didn’t ask. When the solenoid coil is powered, a magnetic field is generated, which allows it to attract the armature and drive the valve stem to move within the valve body; the armature is not an electromagnet. When a magnet is brought near an iron piece, it gets attracted to it; the iron piece itself doesn’t have magnetism, but it does have ferromagnetism. The armature is likely similar in this regard. If the armature has magnetism and its poles remain constant, then the poles of the alternating current coil change, causing the armature to be attracted for half a cycle and repelled for the other half. Therefore, there should be no magnets inside the solenoid valve.

It is the energized coil that generates a magnetic field in the opposite direction to that of the valve stem, thereby pushing the valve stem to move and causing the valve core to shift as well. So it should be the valve stem that is magnetic, rather than the valve core. It is mainly about distinguishing between what a valve stem is and what a valve core is. I am humble and earnestly seek your guidance

This post was last edited by WindBlowsCool on May 13, 2012, at 20:36. I see now: To be precise, there should be an iron core inside the coil of an electromagnet. This iron core remains stationary; its function is simply to enhance the collection of the electromagnetic field and increase the magnetic force, right? ) By the switching on and off of current through the coil, north and south poles are formed on the iron core, which in turn pushes or pulls the armature; and is it the armature that drives the valve element of the solenoid valve? But if it is used for propulsion, then the armature should be magnetic, and its poles should be opposite to those of the iron core in the coil, is that correct?

Why are the core materials of electromagnets different when using direct current and alternating current? Is it because, when alternating current is used, the silicon steel acts as a filter for this current, thereby keeping the north and south poles at both ends of the coil unchanged?

Core of an AC electromagnet: made of silicon steel sheets. This helps to reduce eddy current losses. The core of an AC electromagnet operates in an alternating current environment, and power losses occur not only due to the resistance of the coil but also within the core that is magnetized by the alternating current. The power loss in the core is generally referred to as \"core loss,\" and this loss is caused by two factors: \"hysteresis loss\" and \"eddy current loss.\" Hysteresis loss is the iron loss that occurs in the core during magnetization due to the hysteresis phenomenon; the magnitude of this loss is proportional to the area enclosed by the material’s hysteresis loop. Silicon steel has a narrow hysteresis loop, which results in lower hysteresis losses when used as the core of transformers, thereby **reducing** their level of heating. Given the aforementioned advantages of silicon steel, why isn’t it used in its whole form as the core, but instead is it processed into sheets? This is because the laminated core can reduce another type of iron loss—eddy current loss. During operation, an alternating current flows through the coil, and the magnetic flux it generates is naturally alternating. This changing flux generates an induced current in the core. The induced current generated in the core circulates in a plane perpendicular to the direction of the magnetic flux, which is why it is called eddy current. Eddy current loss also causes the core to heat up. To reduce eddy current losses, the core of the electromagnet is made up of silicon steel sheets that are insulated from one another; the thickness of these sheets is typically 0.35–0.5 mm. This arrangement allows the eddy currents to flow within narrow paths, thereby increasing the resistance in those paths due to the smaller cross-sectional area ； At the same time, silicon in silicon steel increases the electrical resistivity of the material, which also helps to reduce eddy currents.

If an AC electromagnet is used, since the direction of the current in the coil keeps changing, will this cause the spool of the solenoid valve to move back and forth as well? ?