Pneumatic pressure fittings , also called couplings, provide a leak-free means of easily connecting hoses in your compressed air system. Connections can have between 1-6 I/O ports or may have additional functions such as a pressure gauge or integrated shut-off.
How to install pneumatic pressure fittings
The hose can be easily installed by pushing it into the end of the fitting’s release ring until it stops. Internal locking claws automatically tighten around the hose for an instant and secure connection. See Figure 1.
How to remove pneumatic pressure fittings
Push the release ring inward toward the fitting to disengage the locking tabs and pull back on the tube to remove it. The opposite end may be another push to connect fittings, threaded males, threaded females, or threaded males with internal hex connections. Threaded fittings usually have a pre-applied thread lock coating. For a proper seal, the tube must be inserted more fully, as seen in Figure 1 point A. Figure 1 point B shows a thinning of the pipe causing a leak in the seal.
Figure 1: Left image point A shows proper pipe installation. The right image point B shows incomplete insertion.
Advocators
The biggest advantage of push fittings is the quick release system, which allows for simple and easy installation by hand, eliminating the need for tools and adhesives. Due to the ease of connecting and disconnecting airlines, it enables frequent changes of airlines at low cost. They are offered in a wide range of pipe sizes, fittings and thread combinations to suit the desired result. Tameson connectors are RoHS compliant.
negative
Compression fittings require stronger tubes with harder walls to resist internal fork damage. Rigid pipes will be less flexible. Therefore, it may not be suitable for systems where hoses are routed around tight turns. If flexible pipes are desired, we recommend using barbed hose fittings instead of compression fittings. Nylon, polyethylene (PE) or polyurethane (PU) pipe materials are ideal for compression fittings. Also suitable for pneumatic (air) applications. However, it can be used for water applications (see data sheet).
Normal versus unequal connections
Some fittings are available in regular or uneven variations. Regular fittings use the same diameter on all inlet and outlet ports, while unequal fittings have ports of different diameters (larger or smaller) to connect hoses of different sizes.
Connection points
Connections can have multiple connection points from one to six connections. All fittings have at least one port as pressure fittings (except plugs). The way they move through the air (straight, elbow, etc.), regular vs. uneven, and other connection methods (plug, thread, etc.) make the difference in their types.
A connection
These fittings have a connection port, so they terminate the air flow.
Plug and cap fittings
Plug and cap connectors are used when the air flow needs to be temporarily cut off or closed. A cap, Figure 2 left, is used to terminate a pneumatic hose with a plug connection. A plug, Figure 2 right, is used to seal the pneumatic pressure connections and is installed in the same installation/removal maneuver.
Figure 2: Cap compression fittings (left) and a plug for compression fittings (right)
Two connections
The two connectors have a single push type port and a single threaded (female or female) or push type secondary port. Air flows from the inlet port to the outlet port.
direct fit
Straight fittings connect a hose in a straight line with a threaded or female secondary inlet. For an example, see Figure 3.
Straight hexagonal joints
Internal hex straight fittings have a threaded secondary port and an internal hex connection. Internal hexagon straight fittings have a threaded secondary port for connection to a valve and/or a component. The inside of the hexagon can be tightened after the threaded connection is made, and a hex key can be inserted from the push-fit side to tighten the threads. For example, see Figure 4.
Figure 4: Straight In-Hex Internal Pressure Fittings
to elbow
Elbow fittings connect hoses at 90 or 45 degrees to change the direction of air flow. They have a female or female threaded secondary port. Regular elbows have equal arms, while long elbows will have a longer arm. See Figure 5 for an example of a 90 degree elbow joint.
Figure 5: Tensile joints of 90 degree elbow
Direct union connections
Straight union fittings have a pressure type connection at each end to connect two hoses in a straight line. Straight rough fittings have ports of different diameters to connect hoses of different sizes. For example, see Figure 6.
Figure 6: Union direct pressure connections
Elbow union
Elbow fittings connect two hoses and have a 90 degree bend to it. Each port has a push-in connection. See Figure 7 for an example.
Elbow fittings connect two hoses and have a 90 degree bend to it. Each port has a push-in connection. See Figure 7 for an example.
Direct connection to electricity
Straight plug connections connect hoses in a straight line, so one port uses a push-in type connection and the secondary port uses a stem or “plug-in” type connection. Typically, the stem is inserted into an existing compression fitting. See Figure 8 for an example.
Figure 8: Connect straight tension joints
Connecting the elbow to the plug
Plug-in elbow fittings connect hoses at 90 degrees using push-in and plug-in connection ports. For example, see Figure 9.
Figure 9: Elbow tensile joints in the form of plugs
Three connections
The three connectors have two push-in type ports and one threaded or other type port. These connections can have two inlets and one outlet to increase pressure, or one inlet and two outlets to reduce pressure and create two air flows.
ionic junctions
Union Tee fittings create a “T” connection for connecting three hoses of equal diameter using a push-type fitting on all ports. Unequal Union Tee fittings are also available to connect a smaller diameter hose to two larger diameter hoses. See Figure 10 for an example.
Figure 10: Union Tee push fittings
Y joints
Union Y fittings form a “Y” fitting to connect three hoses of equal diameter using a pressure type fitting on all ports. Unequal Y fittings are also available to connect a larger diameter hose to two smaller diameter hoses. See Figure 11 for an example.
Figure 11: Y-Union Compression Fittings
Four to six connection points
Push fittings can also have more connection points, but usually no more than 6. Some examples of joints with more joints are two “Y”, three “T” or cross joints. These connections are for specific applications, but can help reduce overall connections to feed 1 input line and multiple outputs.
For more information, you can read the article about the pressure transmitter .
Functional compounds
Functional combination connectors have additional features that may be useful for your application.
Common additional functional compounds include:
Flow control damper to control the speed of air cylinders by throttling the flow in one direction and muting the sound
Pressure gauge to read line pressure
Pressure regulator to limit line pressure
Check the valves to ensure one direction
Stop lock for external control or flow stop
Selection criteria for compression fittings
Pneumatic fittings must be included in a system that requires connecting hoses. It is recommended to keep things simple to avoid significant pressure drop. For example, if a direct connection is possible, do not use a 90 degree elbow because the elbow will reduce unnecessary pressure.
Other considerations include:
Operating Pressure: Most fittings have a maximum operating pressure of 1.0 MPa, but the pressure must be kept below this level to ensure safe operation.
Working temperature : The connections contain O-rings and plastic parts that may become ineffective if hot air is used or the system is placed in a hot environment.
Special environments : Medical and food industries may require fittings with graded or classified materials.
Applications
Compression fittings are used in all types of compressed air systems, but are most commonly used in applications involving pneumatic cylinders, tools, and equipment. They can be used for water applications, but more measures need to be taken (controlled increased pressure, water compatibility, insert ring, etc.) The press-on connection method allows for quick component changes, so if you have an idea Al is Source for many tools that can be exchanged.
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