Cylinder valves and methods for inhibiting the formation of contaminants in cylinders and cylinder valves

A method for inhibiting the formation of carbonyl compounds in a valve assembly wherein the valve assembly is in contact with carbon monoxide comprising coating interior and exterior components of the valve assembly selected from the group consisting of an inlet port, an outlet port, and a lower spindle with an amorphous hydrogenated silicon compound.

A valve assembly comprising a valve body having a fluid passage therethrough having inlet and outlet ports, a valve chamber in fluid communication with the inlet and outlet ports in the valve body, a first valve for opening and closing the fluid passage to control a flow of gas through the fluid passage, a threaded rod in fluid communication with the fluid passage, the threaded rod in communication with the inlet port and the outlet port, wherein the valve comprises a valve member comprising a lower spindle, an intermediary spindle and an upper spindle in the form of the threaded rod, the threaded rod engages with a valve seat and diaphragm upon which the threaded rod engages in the valve-closing position, wherein the valve allows passage of the gas from the inlet port through the fluid passage to the outlet port when the threaded rod is not engaging the valve seat, and the inlet port, the outlet port, and the valve seat are coated with an amorphous hydrogenated silicon compound.

The valve assembly as claimed in 17 wherein the hydrogenated silicon compound is coated on the surface of the inlet port, the outlet port, and the valve seat by a chemical vapor deposition process.