The threaded connection type of solenoid valve is to connect the threaded port of the solenoid valve to the pipeline, and fix it on the pipeline accordingly. This connection type is suitable for small flow rate and small diameter solenoid valves. Its advantages are simple connection, convenient layout, and the oil pipeline between valves in the system is clear at a glance. Its shortcomings are: scattered layout of components, large space occupied, staggered pipelines, numerous joints, and inconvenient for assembling, disassembling and maintenance.

Because the diameter of solenoid valve is generally small, the most common connection type of solenoid valves is internal thread connection, so it is necessary to know the specific thread connection form. The internal threads of solenoid valves are mainly NPT, PT, RC and G threads.

Solenoid valve refers to the valve with closed cavity, through holes in different positions. Each hole is connected with different tubing. A piston is in the middle of cavity, two electromagnets on both sides of piston. The magnet coil on which side is energized and the valve body will be attracted to that side. Different oil drain holes is opened or closed by controlling the movement of the valve body. In this way, the mechanical motion is controlled by turning the current on and off of the electromagnet in the solenoid valve.
The solenoid valve is widely used in the pipeline of automatic system. The material of solenoid valves should be selected according to the medium characteristics, pressure and temperature in different working conditions. Then let us analyze how to select the material and sealing material of solenoid valve body combined with the use temperature of the medium.

The solenoid valve is an industrial tool for electromagnetic control. As an automatic basic element used to control the liquids, the solenoid valve has advantages, including steady performance, firmness, durability, high sensitivity, etc. It is usually applied to the heating system, compressed air technology, industrial automation, swimming pool, fire-sprinkling system, washing machine, dental equipment, vehicle washing system and irrigation system. The solenoid valve can be divided into three different operation types in working principle: direct-acting solenoid valve, pilot-operated solenoid valve and semi-direct operated solenoid valve.

The solenoid valve symbols are the schematic diagram used to describe functions of the solenoid valve. The schematic diagram is usually applied to the pneumatic system design and product identifications for pneumatic system designers and solenoid valve users to get a thorough understanding of product functions. In the design process, the gas circuit drawing should be paid attention to frequently. Various solenoid valves are transformed into corresponding pneumatic symbols on the drawing. The means of representation is reflected as symbols of solenoid valve.
The solenoid valve symbols constitute of the box, arrow, "T" and characters. The meaning of the solenoid valve symbols is as below.

The solenoid valve is an automatic basic element used to control the fluids. As an actuator, it can be used to control the direction, flow, speed and other parameters of the medium in the industrial control system to achieve the purpose of automatic control. The solenoid valve is an industrial equipment, which realizes its control via the electromagnetic principle. According to the electromagnetic principle, the solenoid valve is powered on, and the electromagnetic force generated by the solenoid valve coil is used to push the valve core and control the on-off of every gas circuit.

The steam solenoid valve is applicable to the actuating mechanism with the steam as the heating medium and used for automatic temperature control. It can binary automatic control and remote control of steam devices, such as steam heaters, radiators, and dryers, as well as the complete set of boiler steam pipelines, such as temperature self-controllers, steam setters, and steam pre-conditioners. So far, the steam solenoid valve has found wide applications to the self-control system in the field of dyeing, textile, printing, food, medicine, cigarette, cement products, petrochemistry, and metallurgy.