Why OSHA Directive 30 PSI Dead End Pressure

The simple answer is air embolism which by definition is gas bubbles in the bloodstream. Small amounts of air often get into the blood circulation accidentally during surgery and other medical procedures (for example a bubble entering an intravenous fluid line), but most of these air emboli enter the veins and are stopped at the lungs. Gas embolism into an artery, termed arterial gas embolism (AGE), is a more serious matter than in a vein, because it may stop blood flow to an area fed by the artery. A gas bubble can lodge in the heart, stopping blood from flowing from the right ventricle to the lungs (this is similar to vapor lock in engine fuel systems).

The symptoms of ‘AGE’ depend on the area of blood flow, and may be those of stroke or heart attack if the brain or heart, respectively, is affected. The amount of arterial gas embolism that causes symptoms depends on location, but in the brain may be a bubble with a volume only a fraction of a milliliter. [1]

In an industrial setting, embolism can be caused by compressed air coming into contact with the skin, piercing though it, and entering into the blood stream. In recent news, a New Zealand truck driver slipped and fell, breaking a compressed air hose off an air reservoir that powered the truck’s brakes. When he fell onto the compressed air fitting, it pierced his buttock and forced air into his body at 100 pounds a square inch.

He was rushed to the hospital with terrible swelling and fluid in one lung. Doctors said the air had separated fat from muscle but had not entered his bloodstream, he was lucky. [2]

EXAIR’s engineered nozzles comply with the OSHA directive of 30 psi maximum dead end pressure without having to reduce inlet pressure and consequently performance. The way this is accomplished is by nesting the orifices in between protective fins. With multiple protective orifices, air has multiple avenues to flow in the event one or the other becomes blocked. An added benefit of the protective fins is that as air exhausts between them, it creates a vacuum which draws in surrounding air and adds it to the air stream. Thus you get more air onto the target than the amount of compressed air used. Amplified air flow is 25 times or more.