Document pBRmg5GV3DQ9LN4rMvdBEX12X

Safety Engineering Tables TABLE 47-1 (Concluded) Vertical Single Sptndle Dtsk Grinders (more than half covered) Grinding and Polishing Belts and Straps (Note 5) Wheel Diam (In) Pipes CFM (Note 4) Max Width (In) CFM (Note 4) Up to 20 21-30 31-53 54-72 1 (Note 3) 2 (Note 2) 2 (Note 2) 2 (Note 2) 500 790 1,770 3,140 Up to 3 5 7 9 11 13 220 300 390 500 610 740 From Exhaust Systems Industrial Code Rule 18 (April 1961) New York State Department of Labor NOTE 4 "Polishing wheels" means made-up' hard wheels laced with abrasive NOTE 2 One branch pipe may be used wherever two or more branch pipes are required, provided the cross-sectional area of the single branch pipe is equal to the combined cross-sectional area of the required number of branch pipes and the air flow into the encircling hood is substantially uniform at all points NOTE 3 "Half covered" means a minimum covenng of not less than 50 percent of the open area over the top of the gnnding wheel NOTE 4 Local exhaust ventilation of high speed machinery shall provide such higher rates of air flow as may be neces sary to control the contaminants NOTE S The listed air flow rates are for short belts and straps (up to six feet on centers) which are completely covered except for the necessary working openings More than one pipe and higher air flow rate for longer belts or straps or for belts or straps which are essentially uncovered shall be provided where necessary to effect control TABLE 47--J EXHAUST REQUIREMENTS FOR WOODWORKING AND MISCELLANEOUS OPERATIONS Pipe Sizes for Indicated Air Volume--Air Velocity is 4000 fpm Branch pipe diam (in ) 3 4 4'h 5 5'/j 6 7 8 9 10 12 Air volume (cfm) 200 350 440 550 660 800 1,100 1,400 1,800 2,200 3,100 From Exhaust Systems Industrial Code Rule IS (April 1961) New York State Department of Labor 1600