IQS Newsroom Articles on Solenoid Valves
About Solenoid Valves and Solenoid Valve Manufacturers Including: Solenoid
Water Valves,
Air Solenoids, Proportional
Solenoid Valves, Pneumatic
Valves & Air
Valves.
Solenoid valves are one of the most common flow control
valves in commercial, industrial, and home tools and appliances. Ice
cube makers, refrigerators and dishwashers are a few home appliances
that operate with solenoid
water valves. Proportional
solenoid valves, air
valves and air
solenoids are manufactured for air and gas flow regulation and are
most often pneumatic. A wide range of industries use pneumatic and air
valves to power industrial tools and motors, for heating and cooling,
electronic, medical and dental equipment. Solenoid hydraulic and water
valves are also used in oil tooling, aerospace, fuel systems and
automotive industries. Hydraulic valves regulate flow of fluid or water
and include proportional
solenoid valves and solenoid
water valves. Solenoid valves provide excellent solutions to regulating
fluid and air flow. The solenoid valve is powered by natural pressure
and electromagnetic force; having fewer moving parts is considered good
design, since moving parts require maintenance. Solenoid valves are also
easily operated by remote devices that activate the solenoid coil, making
solenoid valves extremely useful for operating potentially dangerous
machinery or inaccessible lines.
Solenoid valves control the flow of gases or liquids through tubes, as
regular valves do, but unlike other valves, solenoid valves can be controlled
remotely. Operated electromechanically by a solenoid, which is a magnetized
coil activated by electrical charges, solenoid valves control the flow
of gases or liquids precisely through targeted electrical charges, sensor
cue or by hysteresis (device memory). In many valves - such as
pneumatic and diaphragm valves - liquid or gas pressure changes
help to close and activate the valve. In a normally closed (NC) valve,
a plunging pin or rod within the valve is held blocking the passage of
air or fluid by a solenoid coil; the air or fluid pressure coming into
the valve helps keep the valve shut as long as the pin blocks the passage.
In order for gas or fluid to flow through the valve, an electromagnetic
charge is run through the solenoid coil, which becomes active and lifts
the plunger out of the passage and allows flow through the entire valve.
Normally open (NO) valves are the opposite; they remain open until the
solenoid is activated and pushes down the plunger, blocking flow and
creating pressure to keep the valve closed.
Solenoid valve manufacturers make two general types
of valves: direct-acting and pilot-operated. Direct-acting solenoid
valves have a plunger that is in direct contact with the in-flow opening
in the valve body, or orifice. This plunger is used to open and close
the orifice, which permits or hinders flow. The pilot-operated solenoid
valve, which is actually a combination of a pneumatic or hydraulic
valve and a smaller solenoid valve, works with a diaphragm rather than
a plunger, using differential pressure to control the flow of gases
or fluids. In pilot-operated valves, often the same as diaphragm
valves, there is a solenoid-operated vent which is opened to allow the
pressure to equalize, permitting fluids or gases to flow through the
diaphragm in the valve's larger chamber. Both direct-acting and
pilot-operated valves use solenoid coils to move parts and create flow.
Direct-acting solenoid valves need more power to be activated initially,
but they can remain open (or closed, in a NC valve) with relatively little
power and respond much more quickly to activation than pilot-operated
valves.
A distinction must also be made between pneumatic valves and hydraulic
valves. Pneumatic valves utilize compressed air to regulate flow, while
hydraulic valves use fluids such as water or oil, which compress far
less than gases; thus pneumatic valves can offer highly pressurized gas
flow, while most hydraulic valves regulate fluid flow at lower pressures.
Hydraulic valves can, however, provide powerful force and are frequently
used with water or petro-based oil to move heavy equipment or engine
parts at high speeds. Pneumatic power is considered cleaner and lower
maintenance than hydraulic power, due to the absence of degrading fluids
which produce waste and must be maintained. Both pneumatic and hydraulic
valves can be activated or piloted by solenoids.
Types of Solenoid
Valves
- are used for hydraulic and
pneumatic applications. 2-Way solenoid valves have two ports called
pressure and service ports.
- are for hydraulic and pneumatic
applications. 3-Way solenoid valves have three ports, one being the
pressure port, one the tank and the last, the service port.
- are control air flow in a pneumatic system.
- regulate the release of air.
- use fluid pressure and are ported through the return
line to the reservoir.
- fit easily into a
small area and also measure or dispense small amounts of material.
Mini solenoid valves are particularly useful in medical applications.
- are primarily used in applications that involve corrosion
or chemicals.
-
are similar to the hydraulic version in that they both use pressure.
However, the return port of a pneumatic valve, which uses air, is exhausted
to the atmosphere.
- have direct-acting control valves with linear characteristics.
Proportional solenoid valves control accuracy, hysteresis and repeatability
within close tolerances.
- have three bearing
balls that ride on an inclined plane and turn linear motion into
rotary motion. The magnetic arrangement permits direct rotational motion.
- are electrical devices that control water flow.
Common Terms Related To
Solenoid Valves
- Position sensor whose
voltage output differs through various values.
- A circumstance in which there is no leakage
of air from between the internal sealed ports of the valve, whether in
the energized position or not, in a five second time period. Soap bubbles
are used to detect leakage.
- A situation in which the tubing is pinched in the
valve.
- The maximum voltage to which the coil must be energized
for the valve to achieve its highest specified capacity.
- Energizing a solenoid valve at a constant level
of power for its entire on-time.
- The quantity
of current in amperes flowing through a solenoid valve coil when it is
energized.
- The normal opening and closing of a valve.
- The measure of how many times a valve is able to open
and close within a set period of time.
- Proportion of time that the solenoid receives power.
- A feature that allows for the manual reducing or
controlling of flow.
- Magnetic steel plate that helps transmit magnetic
flux in the magnetic circuit of a solenoid valve from the enclosure to
the sleeve construction. A flux plate is necessary on valves with a body
construction consisting of a non-metallic body.
- Changes
with the output variable in steady-state conditions, caused by a sinusoidal
input variable.
- Association of input to output or the sensitivity of a device.
- The variation between up-scale and down-scale outcomes
in equipment response, when exposed to the same input from the opposite
direction.
- A term that refers to a valve that is closed
when unenergized.
- A term that refers to a valve that is open when unenergized.
- A system in which direct feedback is not supplied to
gauge the response.
- Employing electronic sensors to watch the position
of the valve and provide electronic feedback.
- Increases function of solenoid valves by reducing
power consumption and heat generation. The valve is opened and held open
at decreased power.
- A technique that utilizes a modulated
wave function to control analog devices.
- The ability of the equipment to generate consistent
results on successive tests.
- The space the plunger covers during a state change.