How to Choose the Right Solenoid
Let’s start by examining the basic types of actuators and determining the appropriate solenoid needed to operate them. Most pneumatic valve actuators fall into one of two categories: double-acting (fail in place) or spring return (fail open or fail closed). Typically, pneumatic actuators contain one or two pistons within a cylinder connected to a rod or pinion that operates the valve.
Automotive Lift Repair Tampa Florida Diaphragm actuators also exist, utilizing a rubber diaphragm with a spring attached to a rod to control the valve. Spring return actuators feature springs at the ends of the pistons that return the pistons to a designated position when the air is removed. To move the piston or diaphragm and operate the valve, air must be added to one side while venting air from the opposite side. Failure to vent the actuator will prevent the valve from fully stroking. It’s also essential to vent the pressure side of the piston(s) or diaphragm as it returns to its normal position.
Modern Automotive Lift Repair Tampa Florida rack and pinion actuators come with universal “NAMUR” supply port configurations, allowing for the use of direct mount solenoids to eliminate the need for tubing or fittings. Remote mount solenoids can be positioned on or near the actuators and require piping air to the actuator. These are particularly useful in harsh or high-temperature environments that may affect the solenoid’s electronic operation.
How to Select a Solenoid Valve for a Shutoff Valve
The terms “three-way,” “four-way,” and “five-way” refer to the internal port configurations of the solenoid valve. These ports manage your air supply and the actuator’s exhaust based on whether the electric coil is energized or de-energized. A three-way solenoid has one pressure inlet port, one pressure outlet port for the pneumatic actuator (when energized), and an exhaust port to vent pressure from the actuator’s pressure side when de-energized. Three-way solenoids are mainly used with spring return actuators, pressurizing and venting only one side of the actuator’s pistons. Typically, these actuators have a built-in vent for the non-pressure side.
A five-way solenoid operates similarly to a four-way but features two independent exhaust ports. These solenoids are primarily used with double-acting actuators, allowing you to pressurize and vent each side of the Automotive Lift Repair Tampa Florida actuator’s pistons. Both four-way and five-way solenoids may have one or two electromagnetic coils. Single coil versions will cause the actuator to fail closed or fail open upon power loss, while dual coil solenoids will keep the actuator in place during a power outage. If a four-way or five-way solenoid isn’t available, you can use two three-way solenoids to control each side of a double-acting actuator separately, replicating the operation of a dual coil solenoid.
In general, you’ll want normally closed solenoids for automating your actuators. The terms “normally closed” and “normally open” describe the solenoid’s position when the coil is de-energized. A normally closed solenoid prevents the air supply from reaching the actuator when de-energized, while a normally open solenoid allows air to flow to the actuator in the same state.
Key Questions for Solenoid Selection:
1. What type of actuator do I have (fail open or fail closed)?
2. What should my actuator do if power to the coil is lost?
3. Do I need a direct mount or remote solenoid?
4. Is a normally closed solenoid required (most common application)?
5. Should I choose a three-way, four-way, or five-way solenoid?
6. What is my signal voltage?
7. What port size is necessary for the solenoid body?
8. What materials should the solenoid be constructed from?
9. Does the solenoid need to be explosion-proof or simply watertight?
10. What ambient temperature will the solenoid be exposed to?
11. What is the supply pressure of my air?
With answers to these questions, your solenoid supplier can provide the correct solenoid for your application. These considerations are essential when requesting a solenoid. If you require your actuator to open or close within a specific timeframe, consult your Automotive Lift Repair Tampa Florida supplier, as most have access to sizing tools that can calculate the speed of the solenoid stroke, though this will necessitate answering additional questions.
Overview of Solenoid Valves
Engineers and end-users find solenoid valves particularly beneficial due to their automatic operation, eliminating the need for manual intervention. This allows for easy installation and operation in any system requiring automated flow control and monitoring.
Solenoid valves serve as flow control units that can either restrict or enable flow, depending on their activation state. Here’s how they work in practice:
In a typical spool or poppet valve, the solenoid connects directly to a plunger or a pivoted armature, usually mounted with a spring.
When the solenoid is energized, the coil wrapped around the core generates a magnetic field, which influences the motion of the plunger. This motion either opens or closes the valve, regulating flow. The specific operation—whether the valve opens or closes—depends on the valve type and its design.
Normally Open vs. Normally Closed Solenoid Valves
– Automotive Lift Repair Tampa Florida Open Solenoid Valves: These valves remain open when not receiving an input signal. They allow maximum flow based on the pipeline conditions. When an electrical signal is applied, the valve closes, thus controlling the flow. Once the signal stops, the valve reopens.
– Normally Closed Solenoid Valves: These valves are closed by default and only open when an electrical signal is applied.
Complex Solenoid Valves
Some Automotive Lift Repair Tampa Florida solenoid valve models incorporate advanced circuit technology for more sophisticated functionalities, such as proportional flow or pressure control. It’s important to note that in fluid dynamics, “normally open” typically means the valve allows flow, which differs from its meaning in electronic systems.
Types of Automotive Lift Repair Tampa Florida Solenoid Valves
1. Two-Way Solenoid Valves: These are among the most common and control one inlet and one outlet. They can be normally open or normally closed, depending on the application needs.
2. Three-Way Solenoid Valves: With three ports and two valve seals, these valves can switch between different flow paths in response to electrical signals.