790
APPENDIX
When dealing with tar the stroke of the pump should not be less than 6 inches, while the effective plunger speed should not be greater than 50 feetper minute. To ensure smooth and consistent working with a viscous liquid such as tar it is essential that the suction pipe should be of ample size. The cross-sectional area of the suction pipe should, in fact, be 50 per cent, greater tlian the cross-sectional area of the suction inlet on the pump. Thus, for a pump with a 3-inch suction inlet a 4-inch suction pipe should be fitted.
Single Cylinder Pumps
Capacity, gal. per hour. Diameter of Cylinders. Stroke. Minimum steam pressure required for lifting 50 feet.
r Tar. Liquor. Steam end. Pump end.
400 600 3 inches 2 inches 9 inches 20 1b. sq. inch.
630 900 3 „ 9.1 ^2 ” 9 „ 30 „ „
900 1,350 3 „ 3 „ 9 „ 35 „ „
1,600 2,400 4 „ 4 „ 9 „ 35 „ „
With tar a single cylinder pump is preferable to a two-cylinder type for deliveries of under 2,000 gallons per honr. The above capacities in both tables are those given at normal (not maximum) working speeds.
HYDROMETERS
Twaddell’s.—Each degree is equal to 5° Specific Gravity; to find the equivalent miiltiply by 5 and. add 1,000.
Baumé’s for liquids heavier than water.
To reduce Baumé’s to Specific Gravity. 144 Specific Gravity.
144—Baumé.
To reduce Specific Gravity to Baumé.
144— ---------——■■---= Baumé.
Specific Gravity
Baumé for liquids lighter than water. To reduce Baumé to Specific Gravity. 144 Baumé + 134
To reduce Specific Gravity to Baumé. 144
Specific Gravity
Specific Gravity.
— 134 = Baumé.