Apparatus for pipe purging
An apparatus for providing an inert atmosphere to the inside of a piping assembly prior to and during welding, including a cannister, and a bladder which surrounds the cannister and fits inside of a piping assembly to be welded. The cannister including a purge gas inlet connection fluidically connected to a bladder fill conduit, a bladder return conduit fluidically connected to a pressure relief device, the pressure relief device fluidically connected to a reduced pressure purge gas conduit, a primary purge gas diffuser, a secondary purge gas diffuser, a tertiary purge gas diffuser, and purge gas exit holes. Wherein the bladder fill conduit is configured to introduce purge gas into the bladder. Wherein the bladder is configured to expand and form a seal between the cannister and the piping assembly to be welded. And, wherein the bladder return conduit is configured to evacuate excess purge gas from the bladder.
1 . An apparatus for providing an inert atmosphere to the inside of a piping assembly prior to and during welding, comprising:
a cannister, and a bladder which surrounds the cannister and fits inside of a piping assembly to be welded,
the cannister comprising;
a purge gas inlet connection fluidically connected to a bladder fill conduit,
a bladder return conduit fluidically connected to a pressure relief device,
the pressure relief device fluidically connected to a reduced pressure purge gas conduit,
a primary purge gas diffuser,
a secondary purge gas diffuser,
a tertiary purge gas diffuser, and
purge gas exit holes,
wherein the bladder fill conduit is configured to introduce purge gas into the bladder,
wherein the bladder is configured to expand and form a seal between the cannister and the piping assembly to be welded, and
wherein the bladder return conduit is configured to evacuate excess purge gas from the bladder.
2 . The apparatus of claim 1 , wherein the cannister has a diameter approximately 1 inch less than the smallest inside diameter of the piping assembly to be welded.
3 . The apparatus of claim 1 , wherein the cannister has a length of between 3 inches and 12 inches.
4 . The apparatus of claim 1 , wherein the bladder comprises a flexible, heat and tear resistant material configured to withstand 50 psig of internal pressure.
5 . The apparatus of claim 1 , wherein the pressure relief device is configured to maintain a pressure of between 5 psig and 50 psig in the bladder.
6 . The apparatus of claim 1 , wherein the primary purge diffuser comprises perforated coils constructed of copper or stainless steel tubing.
7 . The apparatus of claim 1 , wherein the secondary purge diffuser comprises layers of steel wool.
8 . The apparatus of claim 1 , wherein the tertiary purge diffuser comprises a metal screen.
9 . An apparatus for providing an inert atmosphere to the inside of a piping assembly prior to and during welding, comprising:
a cannister, and a bladder which surrounds the cannister and fits inside of the piping assembly to be welded,
the cannister comprising:
a purge gas inlet connection fluidically connected to a bladder fill conduit,
a bladder return conduit fluidically connected to a pressure relief device,
the pressure relief device fluidically connected to a reduced pressure purge gas conduit,
at least one purge gas diffuser, and
purge gas exit holes,
wherein the bladder fill conduit is configured to introduce purge gas into the bladder,
wherein the bladder is configured to expand and form a seal between the cannister and the piping assembly to be welded, and
wherein the bladder return conduit is configured to evacuate excess purge gas from the bladder,
wherein the bladder comprises a flexible, heat and tear resistant material configured to withstand 50 psig of internal pressure.
10 . The apparatus of claim 9 , wherein the cannister has a diameter between ⅞″ and 1⅛″ less than the smallest inside diameter of the piping assembly to be welded.
11 . The apparatus of claim 9 , wherein the cannister has a length of between 3 inches and 12 inches.
12 . The apparatus of claim 9 , wherein the pressure relief device is configured to maintain a pressure of between 5 psig and 50 psig in the bladder.
13 . The apparatus of claim 9 , wherein the at least one purge diffuser is selected from the group consisting of perforated coils constructed of copper or stainless steel tubing, layers of steel wool, and a metal screen.
14 . An apparatus for providing an inert atmosphere to the inside of a piping assembly prior to and during welding, comprising:
a cannister, and a bladder which surrounds the cannister and fits inside of the piping assembly to be welded,
the cannister comprising:
a purge gas inlet connection fluidically connected to a bladder fill conduit,
a bladder return conduit fluidically connected to a pressure relief device,
the pressure relief device fluidically connected to a reduced pressure purge gas conduit,
at least one purge gas diffuser, and
purge gas exit holes,
wherein the bladder fill conduit is configured to introduce purge gas into the bladder,
wherein the bladder is configured to expand and form a seal between the cannister and the piping assembly to be welded, and
wherein the bladder return conduit is configured to evacuate excess purge gas from the bladder,
wherein the pressure relief device is configured to maintain a pressure of between 5 psig and 50 psig in the bladder.
15 . The apparatus of claim 14 , wherein the cannister has a diameter approximately 1 inch less than the smallest inside diameter of the piping assembly to be welded.
16 . The apparatus of claim 14 , wherein the cannister has a length of between 3 inches and 12 inches.
17 . The apparatus of claim 14 , wherein the at least one purge diffuser is selected from the group consisting of perforated coils constructed of copper or stainless steel tubing, layers of steel wool, and a metal screen.