We design fire protection systems for large industrial plants with a large area network running in the kilometers.

In such case there could be chances of surge due do sudden closure of a deluge valve, check valve, or fire pump. We do not have time/expertise to carry on surge analysis on software.

I have heard about using tanks for surge.

How would we go about sizing an anti-surge tank?

Is there any basic guidelines based on fire water flow rate/pump discharge pressure to get first cut sizing of a surge  protection tank?

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We have a water storage tank and a diesel fire pump on our project.

Is there any requirement for the pressure relief valve discharge pipe, when connected to a supply tank, to be extended below the lowest possible water level?

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We have a fire sprinkler system with a 550 gpm total sprinkler demand (including hose allowances). The supply duration is 60 minutes. There is no city water supply and we are only utilizing a storage tank.

Is the tank required to have a minimum capacity of 33,000 gallons?

Or, could we rely on fire department response, potentially reduce the tank size, and have a manual fire department connection for tank refill?

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We have a project with a limited water supply that makes it impossible to automatically replace the required fire water in 8-hours. 

Could a larger (1.5 x the required fire flow) water storage tank be an option?

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Our fire water demand capacity is 60,000 gallons, but our current water tank storage capacity is 30,000 gallons. We don't have any space near our current fire water storage tank. 

Is it possible to make another (second) tank with a capacity of 30,000 gallons and connect it to the old tank through pipe?

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​I am currently working on an existing high rise building that requires a fully automatic sprinkler system to be added and the AHJ is requiring a water tank to be added on the property to serve as a secondary supply.

There is no room for a secondary supply.

Can a pool be used to substitute a water storage tank that will supply the building through fire pumps?

What codes could back up this option?

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How can we prevent the formation of algae or microorganisms in water storage tanks for fire protection due to the water being stagnant?

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I'm putting together design-build requirements for a new single-story construction building. The flow test pressure is borderline in my opinion so I'll be calling for a fire pump.

When is a water storage tank required with a pump?

I don't think the system needs one, but I just want to be sure.

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Is it permissible to consider the refill supply for a water storage tank when sizing the tank?

The supply would come in above 20 psi. Thanks in advance.

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NFPA 22, 2018 Edition regarding filling requirement and duration - 

Section 4.2.1.4. states "The water supply shall be capable of filling the minimum required fire protection volume within the tank in a maximum of 8 hours" and at the same time Section 14.4.3 states "The tank shall be kept filled, and the water level shall never be more than 4 in. (102 mm) below the designated fire service level."

If I understand correctly, as soon as the water goes below 4-inches from the normal filled level in the tank (HHL), the makeup water supply should be starting to replenish and the pipe sizes should be provided in such a way that the tank can be filled within 8-hours.

In a fire, as the water is going down, the tank will always start full.

What is the case where the tank would be emptied out (except maintenance) and need to be refilled within 8-hours?

What if we store water in two tanks to allow maintenance - would we not need to meet this 8-hour requirement?

I'm unsure of how these two requirements work together. Appreciate any feedback.

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I’m working in the construction of 4-star hotel. The water storage tank is underground made from concrete and the pump room is located above the water tank. The designer specified the fire pumps to be vertical split-case type! In order to follow code, I proposed to install vertical turbine pumps instead of the specified vertical-split case.

The supervisor Engineer is insisting to follow the specification of the fire pump and pushing me to create an underground pump room in order to install the specified pump set.

Any recommendations to avoid this directive?

I have a bad flooding experiences with this this type of subgrade pump rooms.

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