Free release fire pumps are standard pumps used as fire pumps. These standard pumps are not made for fire pump application, which can cause poor functionality in a sprinkler-pump application due to risk of clogging and instabilities in System pressure.Standard Pumps (DIN or ISO) are used for many different applications, but not as fire pumps for sprinkler systems. This is due to the material specification, design and performance, that do not meet the requirements for a fire pump –and standard pumps should therefore never be used as fire sprinkler pumps.
Following differences typically describe the differences between a Standard pump and a “Listed / according to “ fire-pump:
Specification ______Listed fire pump ___Standard pump____Reason__________
Internal pump parts Non corrosive Cast iron Clogging
Pump curve Stable Unstable Pressure fluctuation
Max permissible flow At NPSH = 5 mtr* Dep. of NPSH Cavitation
Driver sizing At NPSH= 16 mtr** Overloading
Certification ID at nameplate No certificate Identification
*Depends on the Fire Pump Standard – but typically between 4,5 to 5,5 mtr.
** Depends on the fire pump standard – but typically at NPSH=16 mtr. or at max point on power curve