ALEXANDRIA, Va., March 26 -- United States Patent no. 12,257,656, issued on March 25, was assigned to Airgas Inc. (Radnor, Pa.).
"Method for pipe purging" was invented by Scott Laymon (Kingston, Ga.) and Frederick A. Schweighardt (Cypress, Texas).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method of providing an inert atmosphere to the inside of a piping assembly prior to and during welding, including introducing a canister, and a deflated bladder which surrounds the canister, into a piping assembly to be welded. Introducing purge gas, thereby inflating the deflated bladder and sealing the canister against the inside of the piping assembly to be welded. Introducing excess purge gas from the bladder into ...