Air Hose

The Utility AirSpade features a ¾” FNPT inlet equipped with ¾” Universal Coupling. To provide adequate air flow to the tool, Guardair recommends air hose no smaller than ¾”ID. Make sure the air hose is rated at least 150 psi and is operating within its temperature rating. Never exceed the air hose manufacturer’s specifications. See OSHA Standard OSHA 29 CFR 1926.302 (b) (5).

Air hoses should be inspected before everyday usage. Spending most of their time on the ground, air hoses get stepped on constantly and are routinely run over by vehicles. Look for signs of abrasion, punctures, and wear. Use care when transporting and storing an air hose. Minimize abuse and avoid storage adjacent to hot exhaust mufflers or turbochargers.

Standard weight air hose with Universal Couplers.

Light weight air hose stores flat.

Connectors And Fittings

Be sure that connectors and fittings do not restrict the air flow in any manner. Employ fittings that are rated the same size, or larger, for a given air hose ID. AirSpade recommends the use of Universal Couplers – sometimes referred to as “Chicago-style,” or “Air King” fittings. Always use the safety pins supplied with these couplers.

Air Hose Pressure Losses

Compressed air flowing through an air hose will lose pressure from friction and constrictions. Friction loss is proportional to the length of the air hose. Operating pressure, flow rate, air hose inner diameter, and air hose smoothness also determine the pressure loss.

The table below shows the pressure loss for 50 feet of common air hose (including couplings) as a function of air hose diameter (ID) and air flow.

This table can be interpreted with the following example. Assume a Utility AirSpade is equipped with a 150 cfm Supersonic Nozzle connected to an air compressor via a 50 ft long, ¾” ID air hose. From the table, the air hose will see a 12.2 psi pressure loss over its length. In order to deliver 90 psi at the Supersonic Nozzle (for optimal performance), the compressor output should be set at 102.2 psi (90 + 12.2) to make up for the pressure loss.

Alternatively, with the same Utility AirSpade and air compressor, a 1” ID air hose will see only a 2.8 psi pressure loss over its length. Thus, the air compressor should be set at 92.8 psi (90 + 2.8) – only a negligible increase.

Pressure losses also result from kinks and bends in the hose. Using a hose coiled up on the ground increases inefficiency. Guardair recommends placing the compressor as close to the work area as possible to minimize the air hose length.