Glossary 
Analog Position Sensor: A type of position
sensor whose voltage output varies over a range of values.
Body: The component
of a pinch valve that secures the tubing.
Closed State: The
state a pinch valve is in when the tubing is pinched.
Continuous Duty: Energizing
a solenoid valve at a constant level of power for its
entire on-time.
Dashpot: A mechanical
device used to decrease plunger velocity for controlling
noise.
Digital Position Sensor: A
type of position sensor whose voltage output has only
two states.
Drop-Out Voltage: Refers to
the power level at which the internal forces in the solenoid
valve (spring and friction) overcome the magnetic field and can no longer
maintain a latched condition. Drop-out voltage is one of the measurements
used to determine solenoid limits.
Durometer: A standard
for quantifying the hardness of rubber, plastic, and other
non-metallic materials. Typical hardness of flexible tubing
ranges from 50 to 70 Durometer on the "A" scale.
Duty Cycle: The relationship
between the energized and non-energized time of an electric
pinch valve usually expressed as a percentage (%). Duty
cycle is determined by (ON time) / (ON time + OFF time).
For example if a pinch valve is energized for 1 second
out of 4 seconds, the duty cycle is 1/(1+3) = 1/4 = 25%.
Feedback: The output
from a position sensor indicating the position, or state,
of the valve.
Hall Effect Sensor (Hall Sensor): A
type of position sensor that senses magnetic field strength
and produces a voltage that changes with this strength.
Hall sensors can have digital or analog outputs.
Heat Rise: The rise
in temperature above ambient that results from operating
an electric pinch valve at predetermined conditions.
Hold-In Voltage: Refers to the power required to maintain a latched condition within a solenoid, keeping the plunger (or moving core) magnetically latched to the fixed pole. Power required for hold-in is approximately 10% of the pull-in power (4-7W). Operating solenoids at a low power hold level saves energy and heat.
Manual Override: A
button that allows the valve's state to be changed manually.
Media: The substance
that flows through the tubing, either a gas, liquid, powder
or slurry.
Media Pressure: The
pressure of the media inside the tubing.
Micro Switch: A
type of digital position sensor that is mechanically linked
to a valve.
Normally-Closed (N/C) valve: A
pinch valve that in which the tubing is pinched in the
de-energized state.
Normally-Open (N/O) valve: A
pinch valve in which the tubing is not pinched in the
de-energized state.
Open State: The state
a pinch valve is in when the tubing is not pinched.
Pinch Force: The force
exerted by the pinch valve on the tubing in the CLOSED
state, usually enough to set a level high enough to occlude
flow.
Pinch Gap: The distance
between opposed pinching surfaces when a pinch valve is
closed.
Pinch valve: A device
used to pinch and unpinch flexible tubing for the purpose
of controlling flow.
Pinching Surfaces: The
surfaces of components in a pinch valve that pinch the
tubing, usually the pinch ridge and plunger.
Plunger: The component
of a pinch valve that translates during a change of state
and pinches the tubing.
Pneumatic
Pinch Valves: A type of pinch valve that
uses pneumatic pressure to actuate the plunger.
Position
Sensing: Using electronic sensors to monitor
the valve's position and provide electronic feedback indicating
the valve's position to a human user or computer.
Pneumatic 3-Way Control Valve: Typically
a 3-way solenoid valve used to send actuating air pressure
to a pneumatic pinch valve.
Pull-In Voltage: Refers to the power required to overcome internal forces in the solenoid valve (spring and friction) and to reach a latched condition.
Latching is achieved when the plunger (or moving core) has moved through its stroke as a result of the solenoid field and becomes magnetically latched to the pole (or fixed core). The time it takes to move the plunger is called the pulse duration, which is a high power (40-70 W) spike for a short period of time (200-500 ms).
Pulse
and Hold: A technique for increasing performance
of solenoid valves by minimizing power consumption and
heat generation. The valve is opened with a pulse of DC
power and held open at reduced power
Snap-In Tube Loading: A
feature of Acro pinch valves that allows tubing to be
installed in the valve without requiring a free end; the
middle of the tubing "snaps in" the body.
Solenoid Controller (Pulse and Hold): A programmable device designed to be part of the control circuit in a fluid control system. This device is capable of enhancing solenoid performance; including long on times, high cycle rates, power and heat reduction.
Solenoid
Pinch Valves: A type of pinch valve that
employs electrical energy and a solenoid to actuate the
plunger.
Splash Seals: Internal plunger seal
and external mounting seal guard against spills and debris,
prevent contaminants from entering valve, and allow for
cleaning without disassembly.
Stroke: The distance
the plunger translates during a change in state.
Total Opening: The
distance between opposed pinching surfaces when a pinch valve
is open. The total of pinch gap and stroke.
Tube Detection: A sensor technique
for determining the presence of tubing within a pinch valve. By using an
analog hall sensor capable of multi-position output, various valve states
are established. Typical states are; Tube Out-Valve Closed, Tube In-Valve
Closed and Tube In-Valve Open.
Tube Slot: A slot in the side of the body for tubing
to pass through.
