Nozzles shall be within 15% of the nominal diameter.
To check for wear of a known to be 5/16" nozzle:
Check 5/16â€ nozzles with a .344â€ pin gage, if the pin gage does not enter the opening then nozzle passes. If the .344â€ pin gage does fit, check the same nozzle with a.360â€ pin gage. If the .360â€ pin gage goes in, the nozzle fails and a corrective action is required.