The duty pump is the main pump within a system. It should is designed/specified to supply a system with the required flow and pressure for the majority of the time. If there are unusual demands the assist pump will help.
The duty pump that performs most of the work.
A duty pump should be sized to cover the majority of the flow/pressure requirements.
The role of duty pump should be swapped to another pump within the system to spread the wear and prolong the system life, this is usually done at a pre-set interval.
The duty pump is controlled by an electric panel and the pump is automatically started by its pressure switch. The diesel engine keeps on working till the manual stop. The jockey pump stops automatically when pressure is restored. According to the power output of the engine the electrical system can be either 12V or 24V DC. The diesel engine consists of starter motor, fuel system, lubricating system, exhaust system etc. All are mounted on a strong common base frame of mild steel and painted red.