### 1910.94(b)(3)(ii) Grinding Wheels

 Updated resource available on machine guarding for abrasive wheel grinders March 20131910.94(b)(3)(ii) Grinding wheels on floor stands, pedestals, benches, and special-purpose grinding machines and abrasive cutting-off wheels shall have not less than the minimum exhaust volumes shown in Table G-4 with a recommended minimum duct velocity of 4,500 feet per minute in the branch and 3,500 feet per minute in the main. The entry losses from all hoods except the vertical-spindle disc grinder hood, shall equal 0.65 velocity pressure for a straight takeoff and 0.45 velocity pressure for a tapered takeoff. The entry loss for the vertical-spindle disc grinder hood is shown in figure G-1 (following 1910.94(b)).``` TABLE G-4 - GRINDING AND ABRASIVE CUTTING-OFF WHEELS ________________________________________________________________ | | Wheel diameter | Wheel width (inches) | Minimum exhaust (inches) | | volume (feet (3)/min.) _________________|______________________|_______________________ | | To 9.............| 1 1/2 | 220 Over 9 to 16.....| 2 | 390 Over 16 to 19....| 3 | 500 Over 19 to 24....| 4 | 610 Over 24 to 30....| 5 | 880 Over 30 to 36....| 6 | 1,200 _________________|______________________|_______________________ ```For any wheel wider than wheel diameters shown in Table G-4, increase the exhaust volume by the ratio of the new width to the width shown.```Example: If wheel width = 4 1/2 inches, then`````` 4.5 divided by 4 X 610 = 686 (rounded to 690). ````Information last verified March 13, 2013`