Solenoid Valve Symbol

What is the Function of a Solenoid Valve Symbol?

A solenoid valve symbol is a simplified representation of a solenoid valve component, used to indicate its position and purpose in a schematic diagram visually. The solenoid valve is a device that controls the flow of fluids using an electric current.

Types of Solenoid Valve Symbols

Solenoid valves differ in the characteristics of the electric current they use, the strength of the magnetic field they generate, their regulatory mechanism, and the type and characteristics of the fluid they control. As such, different symbols are used to represent each type of solenoid valve:

2/2 Way Solenoid Valve Symbol

The majority of solenoid valves are normally closed 2/2-way valves. The symbol is comprised of two adjacent squares representing the two states of the valve. The ‘T’ symbol in the right-hand square indicates that the valve is normally closed, while the arrow in the left-hand square points in the direction of fluid flow while the valve is actuated. Lastly, the coil on the left-hand side and the spring on the right-hand side indicate the means of pilot control and return control for the valve operation, respectively.

3/2 Way Solenoid Valve Symbol

A 3/2-way solenoid valve has two positions and three connection ports, allowing a single valve can be used to control the fluid flow in two circuits. These valves can be used for multiple applications, such as switching between two circuits or actuating a hydraulic cylinder. Similar to the 2/2 way solenoid valve, this symbol has representations of the coil on the left-hand side and the spring on the right-hand side to indicate the means of pilot control and return control for the valve operation, respectively.

What Solenoid Valve Symbols Look Like in a P&ID

A piping and instrumentation diagram (P&ID) is a detailed graphical representation of a process that includes both the hardware and software necessary to design, assemble, and operate the system. It is similar in design to the circuit diagram of an electronic circuit, using symbols to indicate the components and their locations.

Compared to those used in fluid power diagrams, these symbols are simpler and less detailed. Arrows are used to demonstrate the direction of fluid flow in 3-way and 4-way valves, indicating de-energized flow paths that give fluid flow direction when the valve is at rest (non-actuated).

The various labels are:

• A: Two-way on-off solenoid valve
• B: Angle on-off solenoid valve
• C: Three-way on-off solenoid valve
• D: Four-way plug or ball on-off solenoid valve
• E: Four-way, five-ported on-off solenoid valve

Standardization of Symbols

The International Society Of Automation (ISA) enforces a strict set of standards to ensure uniformity in P&ID symbols. Regardless, there are different ways to represent valves, such as using text descriptions, a unique model called the part number, a tag number, which is a specific component in the system, and a detailed legend.

Skip the Drawing Process With Capital X Panel Designer!

Drawing a solenoid valve symbol manually is a time-consuming process. With Capital X Panel Designer, you can skip the procedure entirely by simply browsing through our library of pre-made symbols and then dragging and dropping them into your schematic. This easy-to-use CAD software will provide a huge boost to your productivity.

Learn more about how to generate electrical symbols automatically.