Activating a high-powered pump to compensate for small leaks is a huge waste. Knowing when to specify a Jockey pump in a fire suppression system design avoids unnecessary costs and headaches during inspections.
If you are a reseller or designer of fire suppression systems, or intend to enter this field, understanding the role of pressurization is fundamental. Contrary to what one might imagine, the need for a jockey pump is not solely linked to the power of the main pump. In fact, its use depends on the nature of the system and the need to maintain stable pressure under normal operating conditions.
Let's explore together a bit more about what the regulations say regarding the recommended use of Jockey pumps. Follow along.
What international standards say: When to designate a jockey according to NFPA 20
The National Fire Protection Association (NFPA) is dedicated to reducing deaths, injuries, and property losses caused by fires and other related hazards. As an international non-profit organization, it develops and publishes codes and standards covering a wide range of topics related to this issue. Governments, businesses, and other organizations worldwide widely use these standards as a reference in implementing safety measures.
More specifically, NFPA 20 details the function of jockey pumps and their sizing, installation, and control requirements. According to it, the main function of the jockey pump (or “makeup pump“) is to maintain the hydraulic system pressure within a pre-established range. It does this by compensating for small leaks and normal pressure drops that may occur in the piping.
Furthermore, NFPA 20 recommends the use of a jockey pump when it is desirable to maintain uniform or relatively high pressure in the system. The goal is to prevent the main pump, which is certainly more powerful, from being unnecessarily activated due to small pressure fluctuations. Frequent activation of the main pump can cause premature wear and the infamous water hammer, which is harmful to the piping. Click here In case you missed the post about Water Ram Strike.
What do national standards say?
The approach in Brazilian ABNT standards and fire department regulations follows a logic similar to NFPA, with adaptations according to the specificities of each state.
In Brazil, the regulations in force until now also do not explicitly define the mandatory use of a jockey pump based on the power of the main pump. However, there is a certain tendency to recommend these pumps for systems where the main pump has a power equal to or greater than 5 hp. It should be noted, however, that this is not a regulation.
When to indicate the Jockey according to NBR 13714 and NBR 10897 standards
The ABNT NBR 13714 standard, "Hydrant and hose reel systems for fire fighting," and the ABNT NBR 10897 standard, "Automatic sprinkler fire protection systems – Requirements," follow a similar logic, although they do not specifically define the mandatory use of a jockey pump based on the power of the main pump. However, since there is a requirement that the fire suppression system have sufficient pressure to meet the system's needs, whether through hose reels and hydrants or automatic sprinklers, the jockey pump ends up being mentioned as a solution to maintain system pressure without the need to activate the main pump, which is generally more powerful and therefore consumes more energy when switched on.
Furthermore, as stated in NBR 10897, the main pump, after the engine starts, can only be deactivated manually via its control panel. Thus, a system without a jockey pump would activate the main pump whenever pressure needs to be restored, and its deactivation would depend on human intervention. Until then, the pump would remain on, consuming energy, and because it is running without flow, it would be prone to significant damage.
Specifics of the Technical Instructions of State Fire Departments
Additionally, it is necessary to pay attention to the Technical Instructions (ITs) of each state. Here is a very important point: each state Military Fire Department in Brazil has its own technical instructions (ITs) and additional regulations. Of course, these instructions are primarily based on the standards mentioned above, but each department can determine its own issues, according to the specific conditions of each state.
That being said, specific state regulations may have particularities regarding the mandatory use of the Jockey pump.
The general rule in most ITs (Technical Instructions) is that a jockey pump is necessary when the system cannot be kept pressurized by gravity. It is understood, therefore, that if the fire reservoir is underground or at ground level, a jockey pump will almost always be mandatory to maintain pressure and prevent the main pump from activating.
The vast majority of technical instructions (ITs) also replicate the NFPA 20 guidelines on the jockey pump shutdown pressure, which should be slightly higher than the main pump activation pressure, ensuring that it can keep the system ready without triggering the main pump. The IT from the São Paulo State Military Fire Department, for example, suggests an additional 1 kgf or 10 mca.
Furthermore, some state technical instructions also stipulate, such as NFPA 20, that the electrical circuit and the Jockey pump controller maintain complete independence.a with regard to the main fire pump controller, avoiding direct interconnections and ensuring system safety in case of failures.”
Therefore, it is essential that designers and installers always consult the Technical Instruction of the Military Fire Department of the state to ensure project compliance. As we have seen, there may be regional particularities.
The Role of the Designer
The decision to use a jockey pump or not can largely depend on the designer's analysis and the characteristics of the system. Therefore, the designer must evaluate the specific conditions of the system, such as the pressurization capacity of the main pump and the need to maintain constant pressure, to determine if a jockey pump is necessary.
Large-scale systems utilize a jockey pump to prevent small pressure fluctuations from triggering the main pumps. Conversely, systems with constant pressure or that operate without significant pressure losses may not require a jockey pump.
Specific Technical Standards and the Designer's Interpretation
In summary, neither NFPA 20 nor Brazilian standards nor fire department technical instructions determine the use of a jockey pump based on the power of the main pump. The need to include it in the fire suppression system design is primarily defined by operational conditions. That is, if there are significant variations in system pressure, for example, due to temperature or leaks, a jockey pump may be necessary.
FAMAC Jockey Pumps
FAMAC offers Jockey pumps for fire fighting, including single-stage pumps from the FSP, FIQN-IN, and FPM lines, as well as the multi-stage FEI line. These options, ranging from ½ to 4 hp, handle pressures up to 160 mca and flow rates up to 8,9 m³.3/ h.
For more information about these products, we suggest accessing the "Firefighting - Jockey" application in the FAMAC Dimensioning Tool. To do this, simply... click here.
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