Pneumatic hose is used to deliver pressurized air to where it’s needed, such as tools, valves, and actuators. By taking a look at what’s available on today’s market, you’ll quickly see that there are many kinds and sizes of hose and tubing. For this reason, you should consider various factors to select a product that will be appropriate for its task.
The first thing to look at is construction. Tubing used in air applications can be made from a single material or have internal reinforcements, usually with textile fibers, to provide greater strength.
Pneumatic hose is usually made up of an inner tube, one or several layers of reinforcing fiber and an outer protective cover. In general, a pneumatic hose will be more rugged compared to tubing. However, it comes at a higher cost.
Your choice of tubing or hose will mainly be influenced by the type of air supply you use and its application. Hose or tubing size is influenced by the flow requirements. Specifications for tubing are usually provided by the outer diameter and wall thickness, while those for hose tend to use inner diameter.
Selecting the right size is very important. An inner diameter that is too small will restrict air flow and cause pressure losses, excess fluid velocity and inefficiency. On the other hand, selecting a diameter that is too large will result in weight, size and costs that are higher than needed.
Another important element to keep in mind is that maximum working pressure. Tubing is rated by manufacturers by measuring its burst pressure at 75°F, then dividing it by a safety factor of 3:1 or 4:1. This determines its maximum pressure. Some products are also built to handle vacuum to around 28 in -Hg without collapsing.
You should take note that the maximum burst pressure ratings are simply used for manufacturing test purposes and aren’t an indication as to whether a product will be able to safely operate above maximum working pressure or handle pressure spikes without damage.