Zone Valves are required for all station outlets and inlets to allow facility personnel to shut off the flow of gases to specific areas in case of an emergency, such as fire or unexpected malfunctioning of system components.

 

There are many different valves and uses for each, but there are only two types of valves allowed in medical gas systems. Valves for positive pressure gases must be cleaned for oxygen service by the manufacturer and must be quarter turn, full port, ball-type valves. They must be of brass or bronze construction, have extensions for brazing, have handles indicating whether they are open or closed and must consist of three pieces which permit inline serviceability.

 

Valves for vacuum or WAGD service are permitted to be ball or butterfly, and are not required to be cleaned for oxygen service.

 

Source Valves are used as a means of isolating the entire facility from the source, and are required to be located at the immediate connection of the source system and the piped distribution system.

 

If no access to the source valve is available from inside the building being served, a Main Line Valve must be installed inside the building.

 

Each riser supplied from the main line must be provided with a shut-off valve, or Riser Valve in the riser, adjacent to the main line.

 

Service Valves allow servicing or modification of lateral branch piping from a main or riser without shutting down the entire main, riser, or facility. Only one service valve for each branch off a riser is required, and it must be placed in the branch piping prior to any zone valve box assembly on that branch.

 

Optional In-Line valves are permitted to be installed to isolate or shut off piping for servicing of individual rooms or areas. Although optional in line valves are not a requirement and are usually not installed due to the extra cost, they can save time and money in the long run. Shutting down entire areas through zone valve boxes when repairing or renovating areas can be costly as a result of not being able to use the entire area, or having to supply the entire area with portable oxygen and vacuum.