The DOT 407 Magnetic Vacuum Breaker is a valve designed to limit
negative pressure (vacuum) in a typical tank trailer. A permanent magnetic force controls the
movement of the valve poppet to open on demand at 4” Hg or greater. All working parts are kept away
from the airflow paths, which promotes easy cleaning and hassle-free repairs. The valve body has a
1” female port inlet to accept a variety of air inlet fittings. A 1/4” female port is standard to
accept a gauge. The unit is equipped with either:
Tef-O-Sil, Viton® or Kalrez® O-Ring seal.