Frequently Asked Questions Abut Pneumatic Equipment

Whether you need assistance selecting the proper pneumatic fittings, tubing, valves or other components, Polyconn has the expertise to help. Our Pneumatic Equipment FAQs provide answers to common questions about pneumatic fittings, plastic tubing, barbed fittings, push-to-connect connections, flow control, and valves. Explore our frequently asked questions on pneumatic basics for practical guidance on installation, compatibility, pressure ratings, sealings, and more or contact Polyconn’s pneumatic experts for help finding the right solution for your pneumatic application.

 

Pneumatic Fittings

How to Connect Brass Fittings

• The exact process for brass fitting installation will vary depending on your selected fitting. As denoted by the name, brass push-to-connect fittings connect by being pushed into place. Brass barb fittings will require a sealant to torque recommended for your fitting’s thread style. For other pneumatic brass fitting configurations, consult your components’ manufacturer instructions or contact Polyconn for assistance.

Barbed Fittings

How to Insert and Install Barbed Fittings

• The majority of metal barb fittings and plastic barb fittings are threaded. Installation can be completed with sealant to torque recommended for the thread style. The same barb fitting installation process also applies to miniature barb fittings.

How to Connect Poly Pipe to Barb Fittings

• Begin barb fitting installation by ensuring your poly pipe is cut squarely. Then press the pneumatic tubing down around the barb fitting until it is seated. This provides a secure pneumatic connection.

How to Seal Barbed Fittings

• The best way to seal barbed fittings will depend on the thread of your particular component. If your pneumatic fitting includes an O-ring, you will require a smooth surface to seal on. If your pneumatic barb fitting features a pipe thread, make sure to use a sealant such as pipe tape.

How to Get Hose Off Barb Fittings

• In some instances, plastic tubing or other pneumatic pipe can simply be pulled off the barb fittings. However, you will usually need to cut the pneumatic tubing off with a very sharp knife. While disconnecting the pipe, take care not to cut yourself or damage the barb fitting as that can provide a leak path once the tube is reconnected.

How Much Pressure Can a Barbed Fitting Hold?

• Pneumatic barb fittings can generally handle more pressure than the connected pneumatic tubing. However, this depends on the material used to manufacture the barbed fitting. Consult your supplier rating and relevant specifications to find information about your exact component.

Pneumatic Tubing

How to Insert or Install Plastic Tubing

• Pneumatic tubing has a straightforward installation process. Cut the tubing end square and press it into the pneumatic fittings. You will feel it slip past the O-ring. Be sure that your pneumatic tube is fully seated.  Metric tubing will follow the same installation processes.

How to Connect Plastic Tubing

• Install a barb fitting or push-to-connect fitting into your device. After cutting the tube end square, press into the fitting until you feel it move past the O-ring or on the barb. Check to make sure that it is fully seated, and then repeat the process with the connecting tube.

How Do I Control Flow in a Pneumatic Tube?

• Generally, flow is controlled in a tube via the installation of a flow control device, such as a needle valve or pinch valve.

What is the Difference Between Working Pressure and Burst Pressure?

• Working pressure is the safe maximum limit for daily use, whereas burst pressure is the extreme point at which a component breaks or explodes. Additionally, working pressure is calculated by dividing the burst pressure by an appropriate safety factor, as part of important tubing technical information, and helps keep a system running smoothly by applying a safety cushion to the burst pressure.

Does Pneumatic Tubing Pressure Capacity Decrease at Higher Temperatures?

• Yes, the pressure capacity of pneumatic tubing decreases significantly at higher temperatures, as standard room-temperature pressure ratings do not apply when heat increases. Instead, thermal energy softens the plastic polymer chains and lowers their overall tensile strength. Most industrial thermoplastic tubes lose 30% to 50% of their pressure capacity when temperatures rise from standard levels.

Which Tubing Material is Best for Pneumatic Systems?

• Selecting the right pneumatic tubing material depends on several factors such as pressure requirements, temperature, flexibility, chemical exposure, movement, and environmental conditions. Certain tubing options are better for certain pneumatic applications, such as polyethylene tubing being best for resisting environmental stress cracking or PVC tubing being best for low-budget, flexible air lines. Different material options meet different requirements.

What is the Best Tubing for a Retractable Air Coil?

• Polyurethane coiled tubing is the best for retractable air coil as it offers superior coil memory, tight bend radius, and flexibility in cold weather. The highly flexible and self-storing tubing option performs well in coiled form with elastic memory and allows a working length of 80-90% of the actual material length. Additionally, nylon tubing also has a stiff memory but handles higher working pressures and temperatures than polyurethane. Nylon tubing also exhibits excellent chemical resistance, which makes this the preferred retractable air coil tubing for extreme conditions.

How Do I Determine the Working Length of a Tube Coil?

• To determine the working length of a tube coil, find the percentage of the total tubing length by measuring the average diameter of the loops, multiplying by pi, and then multiplying by the total number of loops. It may be good to experiment with working lengths to produce a coil that can be stretched comfortably. Polyurethane features flexibility of 80-90% of the actual material length, and nylon has a working length that is 67-75%.

Valves & FRLs

How Does a Quick Exhaust Valve Work?

• Quick exhaust valves are installed at the rod or blind end of a pneumatic cylinder. They are designed to provide a quick extension and retraction of the equipment and operate by increasing the speed of the pneumatic cylinder’s rod to directly expel the exhaust air at the port end of the cylinder.
   

 

Contact Polyconn for Your Pneumatic Equipment

Still have questions about pneumatic components? Polyconn’s team is here to help. We provide the products and expertise you need to keep your pneumatic systems running efficiently. See what our customers have to say in our customer testimonials and explore our pneumatic resources for further information about pneumatic basics. For streamlined component sourcing and fulfillment, we also offer Kitwair®.

For personalized assistance from our experts, contact Polyconn today or call us to have a real person answer the phone to help you find the right components for your application.