Drafting Flashcards
Perfect vacuum, max height
33.9 feet
Practical limit of draft
22 2/3 feet
Water will rise ___ for each pound of pressure removed from the pump.
2.304 feet
Weight of one cubic inch of mercury is
.49 psi
Hg needed =
.885(height)
Atmospheric pressures reduced approx ____ for each ___ of elevation above sea level.
1/2 pound / 100
Elevation above sea level = Loss of lift
1000 feet =
1.22 feet
Elevation above sea level = Loss of lift
2000 feet =
2.38 feet
Elevation above sea level = Loss of lift
3000 feet =
3.50 feet
Elevation above sea level = Loss of lift
4000 feet =
4.75 feet
Elevation above sea level = Loss of lift
5000 feet =
5.80 feet
Elevation above sea level = Loss of lift
6000 feet =
6.80 feet
Elevation above sea level = Loss of lift
7000 feet =
7.70 feet
Power generated by internal combustion engines decreases about ____ for each 1000 feet of elevation.
3 1/2%
An engine which was just adequate at sea level would be about ___ deficient at ____ altitude.
25% / 7000 ft
Rainy weather is accompanied by a ____
reduction of atmospheric pressure
A __ should be used at the bottom, next to the strainer, hitch must be separated, so as to be placed on both sides of the male coupling lugs
clove hitch
With the other end of the rope, tie a ____ on the first coupling above the strainer end, when removing the suction from the water, pull on the rope attached to first coupling above the strainer.
running bowline
Pumps are rated at capacity using a ____ and a lift of ___.
6” suction / 10 feet
None of our pumps are able to deliver rated rapacity when suction lift exceeds ___ and a single ____ is used.
8 feet / 4” suction hose
The restriction imposed on capacity by the 4” suction hose can be partially offset by using ____ .
two sets of 4” hard suctions.
Two sets of 4” suction are equivalent to a _____.
single suction of 5.6 inches.
Transfer valve should be in ____ because the air will be evacuated from the pump quicker and more completely.
Volume
At draft maintain approximately ___ discharge pressure to avoid losing prime.
35 psi
When water is subject to reduced pressure, the boiling point is lowered. If water is too warm (over ____), sufficient air and water vapor may be given off to affect the maximum capacity of the pump.
85º F
Dry Vacuum Test: This should be at least ___ of vacuum.
20” of vacuum
Dry Vacuum Test:
Should not drop more than ____ in ____.
10” Hg in 5 minutes.
Securing Hard Suctions :
Clove hitch at ____ next to strainer; hitch separated to be on both side of male coupling lugs of suction. With the OTHER end of the rope, tie a ____ on the first coupling above the strainer. Secure center of rope to apparatus or any convenient place on the wharf.
bottom / bowline
In most cases, ____ will not be sufficient to reach the water supply.
one 10’ length of suction hose
_____ should normally be considered as minimum and in many cases it will be necessary to use ___.
Two 10’ lengths / three lengths
The suction strainer will be submerged at least ___ below the level of the water.
Two feet
The water should be at least ___ deep where the strainer is located to provide clearance below and sufficient depth above it.
Four feet
