| Here's information on the simplest type of | | | | direction to actuate the valve, and it will |
| air valve; the 2/2 style.The first 2 in the 2 | | | | stay actuated until you move the toggle back. |
| 2 air valve refers to the number of "working" | | | | The detented 2/2 valve may not have an |
| air ports that are found in the valve body. | | | | internal spring, though with standardization |
| That is, the number of ports that supply air | | | | of manufacture, even a detented valve may |
| to the valve, and channel the compressed air | | | | have a spring, since various kinds of |
| to whatever it is that the valve is supposed | | | | actuators may be affixed to that same valve |
| to do.Most 2/2 valves will have numbers or | | | | body.Non-detented valves do contain an |
| letters etched, cast or painted near each of | | | | actuator spring, and the internal valve |
| their two "working" air ports. If there are | | | | mechanism will "spring" back to the other |
| numbers near the ports, the number 1 would be | | | | position when the operator releases the |
| the supply port to bring the compressed air | | | | primary actuator, similar to what happens |
| to that valve. Port number 2 would be the | | | | when the button on a compressed air gun is |
| working port from which air would flow to | | | | released.At ABOUT-air-compressors.com, an |
| accomplish whatever task that you wanted that | | | | e-book entitled All About Air Valves - volume |
| valve to do.If the port designations are | | | | one - will soon be available (end August |
| letters, then port 'A' would be the supply | | | | 06). If you are interested in more |
| port and port 'B' the working port.If the 2/2 | | | | information about air valves, do visit the |
| valve is to be "air operated", that is an | | | | site and download a copy.All 2/2 valves must, |
| external air signal is to be used to shift | | | | when operated, allow air to ultimately flow |
| the 2/2 valve, there will be another port. | | | | to atmosphere. If a 2/2 valve is selected to |
| That port may not have a designation or it | | | | provide air to a closed tank or air vessel, |
| might say '12'. No, that's not a twelve, but | | | | then when the 2/2 valve is shifted to a |
| rather indicates that air will flow from port | | | | closed position, the air will be trapped in |
| 1 to port 2 when an external air signal | | | | the downstream line. You wouldn't select a 2 |
| operates that valve.The second 2 in a 2/2 air | | | | 2 valve to provide compressed air to an air |
| valve indicates the number of positions that | | | | actuator, for example.The exception to this |
| the internal valve mechanism has. In this | | | | rule are inflatable bladders that contain |
| case, two. When this valve is operated or | | | | their own integral 2/2 valves; a bicycle or |
| actuated, it will either open or close. At | | | | vehicle tire being good examples. When you |
| rest, that is when the external valve | | | | connect your 2/2 air supply valve to the tire |
| operator has not been activated, the internal | | | | valve, the tire valve - itself a small 2/2 |
| valve mechanism will either stay open or | | | | valve - is actuated by the supply valve |
| closed.Most 2/2 compressed air valves are | | | | fitting, allowing compressed air to flow into |
| classified as NC. NC stands for normally | | | | the tire. When the supply valve is no longer |
| closed. This means that when the valve is not | | | | actuated, as long as the fill fittings is |
| actuated, it's normal state is closed, and | | | | attached to the tire valve, the line is |
| compressed air cannot pass through it.There | | | | pressurized. That's why, when you pull the |
| are some applications for 2/2 valves where | | | | fill fitting away from the tire, you hear |
| the flow of air through the valve when it is | | | | that characteristic "pssssst" as the air |
| not being operated is desirous. A NO or | | | | that's been trapped between the two valves is |
| normally open valve would then be selected. | | | | vented. The tire valve will have shifted back |
| When this type of 2/2 valve is at rest, | | | | to being closed by the air pressure inside |
| compressed air will flow through it, and it | | | | the tire, thus preventing the compressed air |
| is only when the valve is actuated that the | | | | in the tire from escaping back to |
| flow of air will stop.All 2/2 valves will | | | | atmosphere.Other 2/2 compressed air valves |
| have actuators that will operate or 'shift' | | | | commonly encountered are those push button |
| the air valve.A compressed air blow gun is a | | | | valves on the handle of air tools, and the |
| good example. On it there will be a push | | | | air-horns that are commonly heard at sporting |
| button or a trigger of some kind. When the | | | | events.The air-horns were designed as |
| button is depressed or the trigger is pulled, | | | | distress sirens for small boat operators. The |
| the compressed air will flow through the gun | | | | push button on the top of the gas canister is |
| and out the nozzle to atmosphere. When the | | | | the 2/2 valve, and it's the pressure of the |
| actuator is released, an internal spring (a | | | | compressed gas trapped in the canister that |
| secondary actuator) will shift the internal | | | | forces the valve shut (NC - normally closed) |
| valve mechanism back, and the air will stop | | | | when the button is released.I guess it's |
| flowing. A compressed air blow gun contains a | | | | better to hear an air horn at a football game |
| 2/2 NC air valve.Some other 2/2 valve | | | | than indicating some poor boater's distress |
| actuators are whisker switches, toggles, push | | | | out on the lake; unless it's blasting into |
| buttons, palm buttons, roller cams, electric | | | | your ear, of course!And as always, if you |
| solenoids or compressed air.2/2 valves can | | | | have any questions, please send me a message |
| have detented or non-detented actuators. If | | | | from the contact screen at my web site.Bill |
| the actuator is detented, this means that | | | | Wade's experience in compressed air and other |
| when the operator actuates the valve, the | | | | industries spans decades; from field sales |
| actuator will stay in the position selected | | | | positions through to the corporate |
| until it is again moved by the operator. | | | | presidential office. His sales agency |
| Toggle switches for air valves are often | | | | represents a select group of industrial |
| detented. You flick the toggle in one | | | | firms. Mr. |