FIRE PUMP TESTING QUESTIONS

FIRE PUMP TESTING QUESTIONS

How many Hose Monsters do I need for my pump test?

Generally, pump testers plan on flowing a maximum of 500 GPM per hose. There are other variables to consider such as pump capacity and hose length. We created the interactive Pump Test Hose Calculator that estimates the number of hoses required for a specific pump test based on the pump ratings/capacity, water supply, job conditions, hose diameter/length and nozzle size.

Why should I use the Monster Tester™?

  • Without the Monster Tester — Fire pump tests using multiple hoses require one gauge for each Hose Monster. It requires one person to adjust the water flow and another to take individual readings. Communication between both persons is via hand signals, radio or shouting. Mistakes happen.
  • With the Monster Tester — One gauge is needed to take accurate readings of individual pitots. The Monster Tester can be remotely located at the test header so that the person adjusting the water flow can watch the pressure change. Opening or closing the hose valve is like dialing in target pressure.

Can the Little Hose Monster™ or regular Hose Monster be used on a rooftop standpipe test?

Yes. In fact, a rooftop standpipe test should not be conducted without a Hose Monster. A Hose Monster unit allows a rooftop flow test to be conducted any time of day because no water is dispersed over the side of the building. The Little Hose Monster with a 1 ¾” Pitotless Nozzle or the 2 ½” Hose Monster with an FM Nozzle Insert are often used. Either one is placed directly on the roof. The major difference between both options is that the Little Hose Monster and Pitotless Nozzle weigh only six pounds, whereas the Hose Monster weighs about 30 pounds.

How many hoses does NFPA require to be used?

NFPA does not specify the number of hoses required to perform a pump test. NFPA 20 Table 4.26 provides a required number of hose valves and the minimum hose valves size (typically 2.5″) for installation of pumps. However, the table does not require a specific number of hoses to be used during a flow test. Some AHJs misinterpret this as the number of hoses to be flowed in a pump test. It does not, and we’ve verified this with NFPA.

What is the maximum hose length allowable?

NFPA does not have a requirement for minimum or maximum hose length.

Does length of hose in a fire pump test affect the accuracy of the readings? What effect does friction loss have?

The accuracy of the readings is not affected by the hose length. The pump’s net pressure (discharge minus suction) takes into account the extra work needed to pump water through longer hose. In certain job conditions, hose lengths greater than 50 feet may be required to discharge the water away from the building or landscaping. In these cases, friction loss may overcome the pump’s ability to force enough water through the hoses. Additional hoses usually solve this problem. If the flow-rate per hose is low enough, a smaller nozzle size may be necessary.

What effect does flowing uphill or downhill with the Hose Monster have?

As long as you achieve your required flow (100%, 150%), the pump’s net pressure (discharge minus suction) should not be affected. When flowing uphill, you might have to use either more hose lines or shorter hose due to the extra work the pump has to do.