Pneumatic fittings are small but important elements that connect various parts of pneumatic systems— hoses, pipes, and tubes—to enable the effective supply of compressed air. Although these fittings are small, they play a significant role in the safety, energy efficiency, and performance of a system.
If you are building or repairing a pneumatic system, it is important to choose the correct fittings. The following five factors are necessary to provide the best performance and reliability.
1. Understand Working Pressure
There is a working pressure range for each pneumatic fitting for application. It is essential to remain within the working pressure range:
Too high pressure and components can burst or leak.
If pressure is too low, the system may not be capable of creating enough force to operate properly.
Use only the pressure rating of the fitting to ensure your equipment requirements in order to avoid system failure and achieve maximum performance.
2. Evaluate the Working Environment
Working environment conditions play a major role in determining the life and performance of pneumatic fittings. Consider the following factors:
Operating Temperature
Each fit is individually tested for a particular temperature range. To operate above this range may lead to a failure. Take note that ambient temperature affects compressed air performance—colder temperatures favor efficiency, but higher temperatures lead to reduced pressure and reduced material longevity (especially with nylon or polyurethane tubing).
Contaminants
Airborne contaminants like water, oil, rust, and dirt are common airborne pollutants that can destroy fittings and reduce system efficiency. To protect your system, use proper filtering, like an FRL unit (Filter-Regulator-Lubricator), that purifies incoming air and prolongs the life of your components.
Available Space
Give adequate clearance for installation, servicing, and air flow. Avoid small spots that can overheat or cause vibration issues. Straightforward layouts reduce pressure drops and maximize energy efficiency—keep elbows and bends at a minimum.
3. Choose the Right Material
The material of your pneumatic fittings should be compatible with the application temperature, chemicals exposure, and pressure. The following materials are typical:
Aluminum: Lightweight and corrosion-resistant; most suitable for low-pressure applications.
Stainless Steel: Strong and extremely chemically and corrosion-resistant; well-suited for harsh environments.
Plastic (Polypropylene): Strong, low-cost, and UV-resistant; well-suited for general purpose and outdoor exposure.
Brass: Good machinability and corrosion-resistance; commonly used for small compression and threaded connector fittings.
Composites: Made with materials like carbon fiber or fiberglass; well-suited for high-temperature and chemically hostile environments.
4. Check Compliance and Approvals
Ensure that the fittings meet industry safety standards, especially if your industry is regulated such as food, pharmaceuticals, or medical application. For example, the food product's pneumatic fittings must meet high purity requirements and do not use oil-based lubricants that harbor bacteria.
Understanding what regulations your industry is subject to leads you to select fittings that not only perform well but also meet safety codes.
5. Coordinate Vessels and Types of Connections
Your compatible selection should match the tubing or hose designation—metric or imperial, metal or thermoplastic. It's also critical to differentiate between:
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Pipes
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Tubes
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Hoses
Connection types similarly differ according to your application. Popular types of fittings include:
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Threaded fittings
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Barb-to-barb connections
Selecting the proper pairing ensures leakage-free performance and system longevity.