Is a Jockey Pump Necessary with Small 13R Pump?

2/12/2021

We have a small project (13,800 sqft total) which is a four-story, all residential apartment building, using mostly CPVC pipe. The system is under NFPA 13R.

The city supply is very poor, so we will have a fire pump that meets NFPA 20 (as is required by 13R). The pump is an 8-HP, 70 PSI at 75 GPM.

Is a jockey pump necessary with such a small fire pump?

Normally, for our large commercial NFPA 13 projects, a jockey pump is not even a discussion because we don't want the main fire pump (500 - 1,500 gpm) cycling on just to support system maintenance pressure.

For such a small project with a significantly smaller fire pump, is there any harm in not providing a jockey pump?

The question is not based on cost - the pump room is microscopic and we're already having trouble fitting in all the equipment and controllers as is.

Appreciate you all - thanks in advance.

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Peter

2/12/2021 09:08:31 am

A jockey pump is required under all installations except under a few scenarios when the fire pump is a positive displacement pump per NFPA 20, 2016: 4.26.7. The size of the pump is irrelevant.

2/12/2021 09:11:43 am

Thank you Peter! Had always provided them, but didn't realize it was mandated as part of NFPA 20. Thanks for the standard reference.

matt

2/12/2021 09:39:33 am

I would disagree with peter. NFPA 20 4.26.1 specifically says that a pressure maintenance pump is one approved method - NOT required.

NFPA 20 4.26.7 says you cannot maintain the pressure with the primary pump.

It is not even required that the system pressure be maintained at any particular level. It is also not required that the main pump be activated by a pressure switch. The pump could be activated by a flow switch or other approved means.

2/12/2021 11:06:29 am

Matt,

4.26.1 lists 3 options:

(1) A pressure maintenance (jockey) pump
(2) A water mist positive displacement pump
(3) Another approved means that is not the main fire pump.

I believe the spirit of the question was if a maintenance mechanism was needed at all due to the small size of the pump. The answer to that is, yes. Simplifying that in my statement above to “yeah a jockey pump is required” was meant to mean that only in the limited instances of positive displacement pumps that do their own maintenance of pressure, you need some other external means. The most common, by significant orders of magnitude to achieve that is a standalone ‘jockey’ pump.

With that being said, in regards to the original posters comment about the need for a jockey pump, what would you recommend?

Matt

2/12/2021 11:20:25 am

I would recommend a jockey pump.

Maybe they could tie into a domestic booster? Or if the AHJ allows, just use a small domestic pump.

A jockey pump is not required, but that is what I have always done.

CJ Bonczyk

2/12/2021 10:18:54 am

NFPA 20 - A.4.26 Pressure maintenance (jockey or make-up) pumps should be used where it is desirable to maintain a uniform or relatively high pressure on the fire protection system. A domestic water pump in a dual-purpose water supply system can function as a means of maintaining pressure. A.4.26.2.1 The sizing of the pressure maintenance pump requires a thorough analysis of the type and size of system the pressure maintenance pump will serve.

Jockey pumps are not required by NFPA 20. However, requirements for their installation, sizing, and maintenance exist in NFPA 20. Thus, the reason systems using underground piping for both domestic and fire protection purposes are permitted to operate as pressure maintenance pumps. This is the reason jockey pumps, valves and appurtenances are not required to be listed. The suction valve for a pressure maintenance pump does not need to be an OS&Y and the isolation valves are not required to be supervised.

A jockey pump is required with automatically controlled pumps (unless a way of maintaining system pressures above the fire pump start pressure is provided) and used when system pressures need to be boosted or maintained regularly to lower the chances of pressure surges and decrease chances of waterflow false alarms. Additionally, since fire pumps are not designed for pressure maintenance purposes and should not be used for operating short periods of time to boost system pressure, a pressure maintenance pump is typically placed on the system

Franck

2/12/2021 10:36:20 am

As a fire pump may start automatically upon pressure drop and normally does not stop when a higher pressure is obtained, you may have an issue if there is a pressure drop in your system (small leakage somewhere that slowly put the pressure down) that start your pump automatically if you start it upon a preset pressure in the system.
In that case, you fire pump will run forever, with no -or very limited- flow, which is not desirable.
Another advantage of maintaining the pressure in your system close to the pressure at churn of your pump, is to avoid water hammer.
But a Jockey pump is not the only solution.
You can also have a pressure tank (even though it takes even more space to install).
Or maybe your city water system can provide some sufficient pressure at no flow to maintain your system at a desirable level ?
And note also that this does not apply if your pump is activated by a flow switch, as indicated by Matt

Mike

2/12/2021 12:38:09 pm

A jockey pump is only required where the fire pump is started by pressure actuation. Some systems may use pumps but may not require constant pressurization as is the case with manually operated foam systems.

In this case, the alarm valve pressure switch activated the pump.

Phil W

2/14/2021 12:08:35 pm

Where you do have a large system/s that does need a pressure maintenance pump, I would even consider providing two (one as back up) given the chaos that can happen if the duty jockey pump fails (fire pumps constantly starting, alarms being raised, building evacuations.....) We often offer a contingency spare at least

Onur

2/15/2021 07:07:18 am

Hello to everyone,
There are many variables to consider in the question.
But shortly,
As far as i understand, the pump capacity is able feed drop pressure (leakage) and working pressure.So i think it's applyible.

Thanks for good question and comments.

Best Regards,
Onur,

Is a Jockey Pump Necessary with Small 13R Pump?

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