LABORATORY SUPPLIES AND CHEMICALS 



tion is a comparatively simple matter. The Crowell system of lubrication as applied 

 to all standard Type "D" sizes, is positive and automatically controlled by the air 

 pressure or vacuum. The oil feed valves are adjustable to suit the grade of lubricant 

 used, and can be closed entirely when necessary. Rotates in one direction only either 

 for use as a Compressor or a Vacuum Pump, requiring no changes in the lubricating 

 system which operates from the outlet or pressure side under either compression or 

 vacuum. Connections should be made to the inlet or suction side for vacuum work 

 and it is also advisable, when using as a compressor, to run a pipe from the inlet to 

 such place where a clean supply of air is assured. The heads are provided with water 

 jackets for cooling, when necessary. The flow of water is regulated by the valve 

 which is fitted to the overflow or discharge pipe. "Crowell Rotaries" are also made in 

 other types, special sizes, etc., for lower pressures or vacuums as well as for higher 

 pressures up to 125 Ibs. to square inch, or practically absolute vacuums. Plain or 

 automatically controlled motor driven outfits supplied in all types. 



DETAILS OF CROWELL TYPE "D" COMPRESSORS OR VACUUM PUMPS 



1594 BLOWER AND VACUUM PUMP, Crowell, No. O. D. Designed for 

 intermittent operation and principally for vacuum work, but can also be 

 used for pressure. It is fitted in an oil immersion box, making it prac- 

 tically leak-proof, and will exhaust to a vacuum of from 29 to 30 inches 

 or a pressure up to 25 Ibs. to sq. inch. Capacity about 2 cu. ft. of free 

 air per minute. Inlet and outlet tapped for J^-inch pipe size, and about 

 J /4 H. P. is required to operate it. Speed, 600 R. P. M. Can be used with 

 or without the oil box. Weight with oil box 50 Ibs. net; without oil 

 box 20 Ibs. Floor space (in box) is 15x8 inches. 



List price (with oil box) $60.00 



List price (without box) 47.00 



1595-1 

 1595-1 BLOWERS, High Pressure Rotary Positive. 



AA A B C 



Size of pulley 2%xtyf\ 3x1 4x1^4 5x124 



Cu. in. per rev. free 



air 11'.. 17 30 80 



Cu. ft. per min. free 



air 4 6 iQi/ 2 i%y 2 



R. P. M 600 GOO 600~ 400 



Prices $20.00 24.00 34.00 45 00 



D E 



7x2^ 12x2^ 



200 



35 



300 



67.00 



400 



r>s 



250 

 82.00 



G75 



200 

 120.00 



G 



16x3^ 



1400 



162 



200 



195.00 



