Like the pipes that transport compressed air to its end use, hoses and tubing are an important part of any compressed air system. Usually, hoses, tubing and their quick disconnect couplings are used between the compressor and pipes or between pipes and the end use application. Because they make up a small part of the compressed air system, these components are not given much thought or attention, but they can be the source of pressure loss at end use when not properly selected or serviced. Consider these five factors when choosing hoses, tubing and quick disconnect coupling to prevent unnecessary pressure drops and production losses.
Length: The length of hosing (typically used inside a machine) can impact pressure losses in a system. Hosing is available in standard lengths, but these can be too long. If that is the case, the hose should be shortened to avoid unnecessary pressure drops. Hosing should not be used over long distances. Hosing that is too long is a primary cause of extreme pressure drops. Use pipe or metal tubing for longer distances to maintain required compressed air pressure.
Material: Tubing and fittings should never be made of plastics, which can be corroded by improperly filtered or cooled air. Instead, metals such as copper, stainless steel, brass and aluminum should be used. Metals can be bent to fit system or space restrictions, require few fittings and are more permanent and generally safer than plastic. Hoses are often made of rubber for convenience, but are not as durable as plastic or metal, leading to frequent deterioration and leakage.
Environment: Ambient temperatures can greatly impact compressed air systems as a whole. But when hoses and tubing come in contact with extreme heat, they can sustain irreparable damage. Plastics are more susceptible than flexible metals to increased temperatures. Regardless of the materials used, compressors should always be in a well-ventilated environment to avoid overheating.
Sizing: Like piping, hoses are measured by the inside diameter. To avoid pressure drops, select a hose that is on size larger than the port. Tubing is measured by the outside diameter. Ensuring your measurement references are correct can help in selecting the appropriate size hoses and tubing for your system, ultimately reducing unexpected pressure drops.
Initial Cost: Never select a product solely based on initial costs. While it may seem like a convenient solution that won’t hurt your wallet today, it could have unforeseen impacts down the road. For example, quick disconnect couplings can often be deceiving. When purchasing from a catalogue, many options look similar, differing only in price. However, pressure losses can vary from 1 psi to 20 psi, and sometimes even up to 40 psi when an incorrect size is selected. In addition to extra costs due to pressure drops, choosing low-quality materials can ultimately lead to expensive repairs or replacements.
Pressure losses due to poor connections can force your compressor to work harder. Not only does this lead to higher energy bills, it also wears down parts faster as they struggle to keep up with demand. Knowing the details of your system can lead to lower energy and repair costs. By paying attention to each component – even down to the size and material of your hoses, tubing and fittings, and quick disconnect couplings – you promote better system health and reduce your overall operating cost in the long run.