How to Calculate Hydrant Pump According to SNI – To calculate the hydrant pump must be done following the applicable standards.

The reason is, the hydrant pump is a very important component in a hydrant installation. The calculation of the right hydrant pump determines how the performance of this fire protection system will be.

The hydrant pump itself is a component that functions as a water sucker from the reservoir or ground tank.

Building Hydrant Pump Installation Regulations in Indonesia

How to Calculate Hydrant Pump According to SNI

One of the important regulations about fire safety is the regulation about how to calculate the hydrant pump.

The hydrant installation standard in Indonesia itself refers to the Indonesian National Standard (SNI) and the National Fire Protection Association (NFPA).

Why does the hydrant installation have to follow these standards? Of course, the goal is that all hydrant components in the hydrant installation can function optimally.

This will make the fire hydrant provide maximum protection in the event of an emergency, in this case, a fire.

Then, what are the hydrant pump installation standards that apply in Indonesia? Here are the hydrant pump installation standards according to SNI and NFPA that must be applied.

SNI 03-1735-2000: Procedures for Planning Building Access and Environmental Access for Fire Hazard Prevention in Buildings
SNI 03-1745-2000: Procedure for Planning and Installation of Upright Pipe and Slang Systems for Fire Hazard Prevention in Buildings
NFPA 13: Standard for Sprinkler System Installation
NFPA 14: Standard for Upright Pipe and Pipe Installation
NFPA 20: Standard for Centrifugal Pump Installations

Also Read: “How to Install Fire Hydrants According to the SNI Standards“

How to Calculate Hydrant Pumps According to SNI and NFPA

One of the standards that regulates the installation of hydrant pumps is SNI 03-1745-2000.

This regulation addresses the procedures for planning and installing standpipe and hose systems to prevent fire hazards in houses and buildings.

This system is divided into three classifications or classes, namely:

Class I system: this system must provide a 2 ½ inch (63.5 mm) hose connection for water supply used by firefighters and those trained.
Class II system: a system that provides a 1 ½ inch (38.1 mm) hose box to supply water used by building occupants and firefighters during initial action.
Class III systems: systems that must provide a 1 ½ inch (38.1 mm) hose box to supply water used by building occupants as well as a 2 ½ inch (63.5 mm) hose connection for the supply of large volumes of water used by those trained or firefighters.

The method of calculating hydrant pumps must be adapted to the fire class system.

Multi-storey buildings such as offices are classified in Class I systems because the risk of fire occurring in offices is low.

According to SNI 03-1745-2000, the calculation method for hydrant pumps in Class I Systems is as follows.

The minimum flow rate of the furthest hydraulic pipe must be 550 US GPM
Additional standpipe flow rate must be 250 US GPM
The total does not exceed 1250 US GPM

In buildings equipped with a fire sprinkler system, the calculation of the hydrant pump flow rate used is 150 GPM for occupancy levels with light fire hazards and 500 GPM for occupancy levels with moderate fire hazards.

Here are some of the examples. If the total number of standpipes that are planned to be active during a fire in an office building is 3 pieces.

Based on this plan, the calculation of the total flow rate in the hydrant pump system is as follows:

Total flow rate

=3 standpipes

=550 US GPM + 250 US GPM + 250 US GPM

=1050 USGPM

Based on the calculation of the flow rate in the hydrant pump system, the fire pump capacity that can be selected is 1000 USGPM.

With that being said, the fire pump capacity is in accordance with SNI 03-1745-2000 standard, which does not exceed 1250 US GPM.

In addition to that, NFPA also regulates the calculation of water reserve volume for fire hydrant pumps.

According to the standard, the calculation of the reserve volume of fire fighting water is determined based on the time required by the hydrant pump to extinguish the fire, which is between 30 – 60 minutes.

If the hydrant installation in a building uses a hydrant pump with a capacity of 1000 USGPM with a fire extinguishing time of 60 minutes, the calculation of the water reserve volume of the hydrant pump in the hydrant system is as follows:

Fire fighting water volume

Hydrant pump capacity x Length of fire extinguishing time

=1000 USGPM x 60 minutes

=60,000 USG

=227 m3 (conversion result)

Based on the results of the calculation of the hydrant pump water reserve volume, the volume of water needed for firefighting for 60 minutes is 230 m3 (rounded).

So, there you have it! How to Calculate Hydrant Pump According to SNI!