US 12,257,656 B2
Method for pipe purging
Scott Laymon, Kingston, GA (US); and Frederick A. Schweighardt, Cypress, TX (US)
Assigned to Airgas, Inc., Radnor, PA (US)
Filed by Airgas, Inc., Radnor, PA (US)
Filed on Jan. 27, 2022, as Appl. No. 17/585,724.
Claims priority of provisional application 63/142,088, filed on Jan. 27, 2021.
Prior Publication US 2022/0234130 A1, Jul. 28, 2022
Int. Cl. B23K 9/32 (2006.01); B23K 101/10 (2006.01)
CPC B23K 9/326 (2013.01) [B23K 2101/10 (2018.08)] 9 Claims
OG exemplary drawing
 
1. A method of providing an inert atmosphere to the inside of a piping assembly prior to and during welding, comprising:
introducing a cannister, and a deflated bladder which surrounds the cannister, into a piping assembly to be welded,
introducing purge gas into a purge gas inlet connection fluidically connected to a bladder fill conduit, thereby inflating the deflated bladder and sealing the cannister against the inside of the piping assembly to be welded,
introducing excess purge gas from the bladder, through a bladder return circuit into a pressure relief device, thereby producing a reduced pressure purge gas stream,
introducing the reduced pressure purge gas stream into a primary purge gas diffuser, thereby producing a first diffused purge gas stream,
introducing the first diffused purge gas stream into a secondary purge gas diffuser, thereby producing a secondary diffused purge gas stream,
introducing the secondary diffused purge gas stream into a tertiary purge gas diffuser, thereby producing a third purge gas stream,
introducing the third purge gas stream into the inside of the piping assembly to be welded.