https://catalog.data.gov/dataset/patent-at-e401519-t1-translated-residual-pressure-valve
U.S. Department of Health & Human Services - Patent AT-E401519-T1: [Translated] RESIDUAL PRESSURE...
The residual pressure valve comprises a rubber tube (2) which acts as a valve seat and holds the gas control component (1) under tension. The control component...
department of health human