Operating The Fire Pump Flashcards
Incoming pressure should not fall below. ? Psi
20
Due to possible cavitation in the pump and disruption of public supply
2.5 or 3in supply lines should not exceed — feet.
- Friction loss may be too great to supply water.
When preforming Relay operations what initial lay should be used
Reverse lay
Most direct lay when supplementing hydrant pressure or drafting.
Reverse lay
When switching to a supplemental water supply tank to pump should be…
Closed
Percentage method equation
Percent drop = (static - residual)(100)
—————
Static
Percent method
Lines available.
> 10 - 3 lines
11-15 - 2 line
16-25. - 1 line
First digit method
Multiple first digit of the static need by 1 2 and 3.
If the residual pressure is less than the multiple of one than 3 lines may be used
If less than 2x - 2 line
Less than 3x - 1 more line
Max vacuum most pumps can develop
22in hg
Draft site selection 3 things
Amount of water available **
Type of water
Accessibility.
Amount of water around the strainer for Max capacity.
2 feet on top
Desired two fee all around.
Low level strainer min depth
2 inches
Temp of water that impacts drafting
Below 35
Above 90
Most common air leaks during drafting
Open drains and valves
Operations from draft problems
Air leaks on intake side.
Whirlpool
Air Leak due to defective packing
