Federal Signal offers a line of air horns in a variety of tones and sizes for the industrial marketplace. High, medium and low tones are available which provides a wide range of frequencies and high sound output. Federal Signal air horns feature a one-piece, cast aluminum alloy housing which has been treated to provide corrosion resistance. The horns include specialized long-lasting stainless steel
diaphragms. These precisely machined horns will yield peak performance at proper working air pressures and are virtually indestructible. The 3- and 4-inch horns (Models 3H, 4H, 4M) have threaded female pipe connections. The Model 6H features flanges for additional support.
Federal Signal air horns operate with 20 to 150 p.s.i., (pounds per square inch) but they are tuned for 80 to 90 p.s.i. operation. The horn frequency (pitch) depends on both the diameter and length of the projector. Decibel output at 10 feet is 122dBa (132dBa @ 1m). The horns require a 120VAC Federal Signal air valve (sold separately); can be used with Model EVS with the 3H, Model EVM with the 4M and Model EVL with the 6H (sold separately). This horn can also be operated with a manually operated valve in areas where no electricity is available. In either case, there must be an air supply available for the horn to operate (sound). Air horns can be used indoors, outdoors, or anywhere compressed air can be provided. Federal Signal Air Horns are the loudest audible signals offered for indoor applications. They are not subject to sparking and are used for hazardous locations (the valves need to be located in a non-hazardous location). 5 Year Limited Warranty.