Lesson 14- Pump Operation- Hydrant Operations Flashcards
when pressure drop is not over 10%
hydrant should supply three 1 1/8” additional lines
when pressure drop is not over 15%
hydrant should supply two 1 1/8” additional lines
When pressure drop is not over 25%
hydrant should supply one 1 1/8” additional lines
purpose of the pressure control device
to control the excessive pressure increase when properly set
ex) when one or more lines are in operation and one line is suddenly closed, the pressure build up may be sufficient enough to affect the remaining lines
When a pump is connected to a hydrant, it is desirable to maintain at least how many pounds of pressure on the compound (intake) gauge
5-10 pounds of pressure
How can I tell my pump is running away from the water
feeling suction where it enters pump inlet (keystone).
suction is soft and flabby
What is the condition where vapor cavities are formed in the pump which can cause serious damage
cavitation
what is a reliable way to determine cavitation point of a pump under any suction condition
- open throttle gradually watching engine tachometer and discharge gauge
- an increase in engine speed without a corresponding increase in pressure indicates cavitation
pump operator suppling a ladder should pump how much psi above the required operating pressure after filling the lines laid to the base of the ladder
*this will ensure against an excessive pressure drop when ladder pipe is first opened
25-40 psi
when pumping between pressure or volume, the general rule of the Department is to choose pump position that will
give desired results at the lowest engine speed
