Pumps that are used for firefighting are designed and chosen in such a way that they meet the pre-calculated pressure at water plume and necessary flow rate which overcomes the plant resistance during fire. Fire pumps basically pressurize the sprinkler systems, hose installments in fire cabinets and hydrant installments which we call fire station inlet. Fire pump systems are composed of main pumps and jockey pumps. Main pumps must be designed certainly with a backup. In case of using a main fire pump in the system, there must be a backup pump with same capacity. In case of having more than one pump, providing that at least 50% of total capacity to be made backup, sufficient amount backup pump are used. For example a system having 2 main 1 backup pumps, each of pumps can be chosen as meeting the 50% of system capacity.
The most accepted standard in the world related to fire pumps is NFPA20. Also in our fire regulation there exist the articles that this standard specifies. For this reason, NFPA20 standard have a huge importance for us.
What Are The Pump Selection Criterion According to NFPA20?
The two important features that are specified in fire pumps related standards.
“Fire pumps must be listed and approved by competent body on fire fighting.”
Pressure corresponding to 150% of nominal flow rate value, must not be lower than 65% of nominal pressure. Closed hold-down pressure must not be more than 140% of nominal pressure.