The ornamental design for a gas regulatory pressurevessel, as shown and described.
FIG. 1 is a top view of a gas regulatory pressure vessel;
FIG. 2 is a bottom view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a first lateral view thereof; and,
FIG. 6 is a second lateral view thereof.
The broken lines depict portions of the gas regulatory pressure vessel that form no part of the claimed design; the broken lines form no part of the claimed design.