Hoffman Specialty Introduces the New Model 508 Hygroscopic Air Vent

An updated and lower priced replacement for the current Model 500 Air vent, the 508’s compact, low profile design allows it to fit under the cover of the baseboard and makes it ideal for a variety of applications. The vent can be set for manual or automatic venting of water radiators by simply turning the fiberglass knob cartridge portion of the vent. Since the cartridge also contains the hygroscopic discs, they can be easily replaced without draining the heating unit.

The 508 Vent uses the hygroscopic principle, a simple, standard method of automatically bleeding air from heating systems. The principle works on the basis of cellulose fiber discs changing volume between their dry and water soaked state. The discs expand more than 50 percent in volume when they become soaked with water.

The expanded discs seal off the air vent passage within a few seconds. When the water is removed, the discs dry out and contract to their original volume, thus reopening the air passage. Drying time depends on the temperature.

® Brass body – chrome plated ® Hygroscopic disc-type vent ® Built-in check ball valve ® 1/8” NPT straight male shank ® Automatic or manual venting of water systems ® Automatic venting of steam systems ® Maximum working pressure    · ® Steam – 15 psig (1.0 bar)    · ® Water – 50 psig (3.5 bar) ® Maximum working temperature – 230F (110C)

Hoffman Specialty, a unit of ITT Industries, is a leading manufacturer of steam traps, regulators and valves for residential, commercial and industrial applications. For more information about the company’s products or services, contact Hoffman Specialty, 3500 N. Spaulding Avenue, Chicago, IL 60618; phone (773) 267-1600; fax (773) 267-0991; Internet address http://www.hoffmanspecialty.com.