Valve for pressurized canister with non-constant thread

A valve for a pressurized canister comprising, in combination:

• a housing having a central aperture extending therethrough, a first set of external threads, and a second set of external threads positioned radially inwardly of the first set of external threads;
• a sealing member positioned in an axially outward end of the central aperture and axially moveable to seal and unseal the central aperture;
• and
• a spring biasing the sealing member axially outwardly;
• wherein the thread has a constant diameter along its length, a first portion having a pitch with a first value, and a second portion having a pitch with a second value that is different than the first value.

A pressurized canister valve assembly comprising, in combination:

• a canister having a threaded opening;
• a housing having a central aperture extending therethrough, a second aperture in fluid communication with an exterior of the housing and the central aperture, a first set of external threads, and a second set of external threads positioned radially inwardly of the first set of external threads, the second set of external threads engageable with the threaded opening of the canister;
• a pressure relief valve positioned in the second aperture;
• a sealing member positioned in an axially outward end of the central aperture and axially moveable to seal and unseal the central aperture;
• and
• a spring biasing the sealing member axially outwardly;
• wherein the second set of external threads has a thread pitch that has a non-constant value along its length and a constant diameter along its length, and the threaded opening of the canister has a thread pitch with a constant value along its length.