WAC 296-818-30015. Blast cleaning nozzles

You must make sure nozzles are all of the following: (1) Mounted on a support when not in use; (2) Equipped with operating valves that are manually held open. Note: To help prevent the buildup of static charges, pressurized tanks used to supply abrasive should be: 1. Connected to the manual control of the nozzle; and 2. Have the relief valve or opening located so it can safely vent.