The design of pneumatic fittings should allow the free flow of required air or gas without any opportunity for significant drops in pressure. Pipes and hoses should be configured as simply as possible, so that no energy is lost in the air’s passage through the system. Always use straight runs wherever possible, and only use elbows and Ts if absolutely necessary.
When choosing your pneumatic fittings, there are some key environmental factors that must also be taken into account.
The operating temperature specified by the manufacturer defines the range of temperatures or the operational temperature ratings within which the particular fitting is designed to work. This is measured in degrees Celsius (°C) or degrees Fahrenheit (°F), and the fitting may well fail if it is made to operate above or below this specified range. It must be borne in mind that the ambient temperature of the inlet air to the compression unit will affect the compressed air output.
As air heats up or rises the pressure drops, so industrial automation equipment should generally only be used in a controlled temperature environment. In general terms, every 5º F of temperature reduction produces a 1% improvement in efficiency and power conservation, but both high ambient air temperature and low intake pressures will significantly affect performance. It’s also a fact that an increase in operating temperature will cause a reduction in the operating pressure of polyurethane and nylon tubing.
The most common air contaminants are water, oil and particulates, such as dirt, rust and metal shavings. Such contaminants in the air intake are commonly removed by the filtration system, usually comprising a filter-regulator-lubricator unit (FRL). The lubricant also acts as a coolant in some types of compressor, but there is sometimes a danger of the heated lubricant getting back into the inlet air and causing contamination there. Additional contaminants in the form of bacteria or microorganisms can also be critical in some types of application, such as pharmaceuticals or food.
It seems simple, but it is essential to ensure that there is sufficient space around the installation to allow the best configured construction, as well as access for maintenance and repairs. It should be large enough to allow pipework to run naturally, and to permit a free flow of ambient air so the space doesn’t overheat externally. The equipment also needs to be stable with no possibility of vibration.