A jockey pump is one of the smallest pieces of equipment in a fire protection system, but a poorly sized or misconfigured unit can mask leaks, trigger nuisance fire pump starts, and create wear that shortens the life of the main fire pump. Jockey pump sizing for fire protection systems is governed by NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, and is referenced by the National Building Code of Canada, provincial fire codes, and the International Fire Code throughout the United States. This guide walks engineers, contractors, and facility managers through the calculations, pressure settings, and selection logic needed to specify a jockey pump that actually does its job.<\/p>\n\n\n\n
A jockey pump, also called a pressure maintenance pump or makeup pump, is a small centrifugal pump installed in parallel with the main fire pump. Its job is to keep system pressure above a defined setpoint between fire events. Sprinkler piping, standpipes, and underground fire mains always experience small pressure losses from minor leakage, temperature changes, and aged check valves. Without a jockey pump, those small losses would eventually drop pressure enough to start the main fire pump, which is not designed to cycle for routine pressure makeup.<\/p>\n\n\n\n
By holding pressure steady, the jockey pump preserves the readiness of the main fire pump, reduces wear on the diesel or electric driver, and prevents false alarms at the waterflow switch. NFPA 20 treats the jockey pump as auxiliary equipment, but its correct operation is a key indicator of overall fire protection system health.<\/p>\n\n\n\n
NFPA 20 does not prescribe a specific jockey pump size, but Section 4.27 and Annex A provide the framework. The standard requires that the jockey pump be sized small enough that it cannot keep up with even a single sprinkler discharge. If the jockey could refill the system faster than a single sprinkler releases water, the main fire pump would never start in an actual fire. This is the single most important sizing principle.<\/p>\n\n\n\n
NFPA 20 also requires a dedicated jockey pump controller separate from the fire pump controller. The jockey controller is typically UL listed under UL 508A as a regulated industrial control panel rather than under UL 218, which applies to the fire pump controller itself. The jockey pump should draw from the same source as the fire pump, be piped with its own check valve and isolation valve, and be wired to a reliable power supply with provisions to alarm on failure.<\/p>\n\n\n\n
The flow capacity of a jockey pump should equal the expected leakage rate of the system, not the demand of the main fire pump. A widely accepted rule from NFPA 20 Annex A is to size the jockey pump at no more than the flow from one sprinkler operating at the minimum design pressure. For a standard spray sprinkler with a K-factor of 5.6 operating at 7 psi, the discharge is approximately 15 gpm. A jockey pump sized between 5 and 10 gpm is sufficient for most commercial buildings.<\/p>\n\n\n\n
For larger systems with multiple risers or storage tanks, leakage may justify a slightly larger jockey pump, but the upper limit is still bounded by single-sprinkler flow. Oversizing is a common error in retrofit work, where contractors sometimes specify 25 or 50 gpm jockey pumps because the unit was readily available. That capacity can refill the system faster than a single sprinkler can discharge, which delays main fire pump activation and may violate code.<\/p>\n\n\n\n
The jockey pump must develop enough head to maintain system pressure at a value slightly above the main fire pump start setpoint. The total discharge pressure should equal the static pressure required by the highest point of the system, plus a margin for pressure switch differentials and minor losses.<\/p>\n\n\n\n
A practical calculation looks like this: take the fire pump churn pressure, subtract the elevation difference between the pump room and the highest sprinkler, then add a 10 psi buffer above the fire pump cut-in. For a system with a 125 psi rated fire pump at churn of 165 psi serving a high-rise with 200 feet of vertical rise, the jockey pump needs to develop roughly 175 to 180 psi at low flow. Most jockey pumps for commercial buildings are multistage vertical turbines rated between 100 and 250 psi at low flow.<\/p>\n\n\n\n
Correct pressure switch settings are as important as pump sizing. NFPA 20 Annex A provides a recommended sequence:<\/p>\n\n\n\n
Jockey pump start point: set 10 psi below the jockey pump churn pressure. Jockey pump stop point: set at jockey pump churn pressure. Fire pump start point: set 5 to 10 psi below the jockey pump start point. Fire pump stop point: typically manual stop in modern installations, or set well above the jockey pump churn if automatic stop is permitted.<\/p>\n\n\n\n
This stacking ensures the jockey pump always responds first to a pressure drop. The main fire pump only starts when the jockey cannot keep up, which happens only when actual sprinkler flow is occurring. The 5 to 10 psi differential between jockey stop and fire pump start prevents the fire pump from cycling on small pressure dips.<\/p>\n\n\n\n
Three pump configurations dominate the North American market for fire protection pressure maintenance:<\/p>\n\n\n\n
The most common choice for commercial buildings, vertical multistage pumps deliver high pressure at low flow with a compact footprint. Stainless steel impellers and shafts are standard, and the pumps typically operate at 3500 rpm. Brands such as Grundfos CR, Goulds e-SV, and Xylem Lowara are widely specified across Canada and the United States.<\/p>\n\n\n\n
Used where vertical clearance is limited, horizontal multistage pumps offer similar performance to vertical units. They tend to occupy more floor space and are less common in new construction but appear in retrofits where ceiling height is restricted.<\/p>\n\n\n\n
Less common today, regenerative turbine pumps deliver high pressure at very low flow. They are sometimes used for jockey duty on small systems but have largely been displaced by multistage centrifugals due to noise and efficiency.<\/p>\n\n\n\n
Jockey pump controllers are simpler than fire pump controllers but still require attention. A typical jockey controller includes a pressure switch, motor starter, run indicator, hand-off-auto selector, and dry contacts for remote monitoring. NFPA 20 requires the controller to be listed for the application and located within sight of the pump or in the same room.<\/p>\n\n\n\n
Most jockey pumps run on 208, 230, 460, or 575 volt three-phase power depending on the regional standard. In Canada, 575 volts is common in commercial and industrial installations, while 208 and 460 volt service dominates in the United States. Single phase 230 volt jockey pumps exist for small buildings up to about 1 horsepower. The motor should be rated for continuous duty, even though actual run time is short, because frequent starting and stopping can generate heat in the windings.<\/p>\n\n\n\n
An undersized supply branch circuit will trip on inrush during a normal start cycle, which then disables pressure maintenance. Coordinating breaker sizes and conductor ampacity with the motor full-load amperage is essential during electrical design.<\/p>\n\n\n\n
The jockey pump connects to the fire pump discharge piping downstream of the main fire pump check valve. A typical assembly includes a suction isolation valve, the jockey pump itself, a discharge check valve, a discharge isolation valve, and a pressure gauge. All isolation valves on the fire protection side should be UL listed or FM approved indicating valves with tamper switches, since NFPA 25 requires supervision of any valve that controls water flow to the fire protection system.<\/p>\n\n\n\n
The jockey pump check valve is critical. It prevents backflow when the main fire pump runs, which would otherwise spin the jockey impeller backward and damage the pump. A spring-loaded silent check valve sized for the discharge pipe diameter is the standard choice. A pressure gauge with a snubber installed on the discharge side allows operators to verify pump performance during weekly inspections.<\/p>\n\n\n\n
NFPA 25 requires weekly visual inspection of the fire pump room, including verification that the jockey pump cycles correctly and maintains pressure. A typical weekly test bleeds a small amount of water from a test cock to drop pressure and confirm the jockey starts at the set point. Monthly inspections should verify the controller status lights, pressure gauge readings, and isolation valve positions.<\/p>\n\n\n\n
Annual pump performance testing under NFPA 25 covers the main fire pump but a properly functioning jockey pump should also be confirmed during the test. If the jockey is cycling more than 10 times per hour during a normal day, the system likely has a leak that needs to be located. Excessive cycling shortens motor life, wears the bearings, and can also indicate failing check valves elsewhere in the system.<\/p>\n\n\n\n
Several recurring problems show up in inspection reports across Canadian and US fire protection systems:<\/p>\n\n\n\n
Oversized jockey pumps that prevent the main fire pump from starting on a single sprinkler flow are the most frequent code violation. Reducing flow by trimming the impeller or replacing the pump with a smaller unit is the standard remedy.<\/p>\n\n\n\n
Pressure switches set too close together cause the jockey and fire pump to start nearly simultaneously, which defeats the purpose of the pressure maintenance scheme. Always confirm a clear differential between jockey stop and fire pump start.<\/p>\n\n\n\n
Failure to supervise the suction or discharge isolation valves with tamper switches creates an unsupervised path to disable the jockey pump, which is an NFPA 25 issue during inspection. UL listed indicating valves with integral switches solve this in one fitting.<\/p>\n\n\n\n
Inadequate clearance around the pump for maintenance access leads to deferred service. NFPA 20 requires sufficient working space, typically 3 feet around the assembly, and most authorities having jurisdiction will cite a violation for cramped installations.<\/p>\n\n\n\n
NFPA 20 is referenced by both the National Building Code of Canada and the International Fire Code, so the technical sizing requirements are functionally identical on both sides of the border. Local variation appears in three areas. First, ULC listing is required for fire pumps and associated equipment in most Canadian jurisdictions, while UL or FM is accepted in the United States. Many manufacturers carry both listings, but specifications should confirm the correct mark.<\/p>\n\n\n\n
Second, electrical standards differ. The Canadian Electrical Code, CSA C22.1, applies in Canada and uses CSA marks on equipment, while the National Electrical Code, NFPA 70, applies in the United States. Specifying a controller that is dual listed avoids project delays. Third, seismic requirements in British Columbia, Quebec, and parts of the western United States may require anchoring and bracing details beyond the standard NFPA 20 mounting requirements. These should be reviewed against the local seismic provisions of the building code.<\/p>\n\n\n\n
Cold climate installations across Canada and the northern United States need attention to freeze protection of the pump room and the suction piping. NFPA 20 requires the pump room to be heated to at least 40 degrees Fahrenheit, and supply piping from outdoor tanks or yard mains needs adequate burial depth to remain below frost line, typically 6 to 8 feet across the Prairie provinces and the northern Midwest.<\/p>\n\n\n\n
Specifying a jockey pump is straightforward once the system parameters are known. Identify the fire pump churn pressure, the elevation of the highest sprinkler, and the expected leakage rate of the system. Use these to determine the required pressure and flow, then select a multistage centrifugal pump that operates near the midpoint of its curve at design conditions. Confirm UL or ULC listing, specify a dedicated controller, and coordinate the pressure switch settings with the fire pump controller during commissioning.<\/p>\n\n\n\n
ValveAtlas supplies UL listed and FM approved jockey pumps, fire pump trim assemblies, indicating valves with tamper switches, silent check valves, and the supporting fittings needed to complete a code-compliant fire pump room installation. Our team works with mechanical engineers, fire protection contractors, and facility managers across Canada and the United States to specify the right equipment for new construction and retrofit projects. Contact the ValveAtlas team to discuss your jockey pump and fire protection valve requirements, request a project quote, or get technical support on a specification in progress.<\/p>","protected":false},"excerpt":{"rendered":"
A jockey pump is one of the smallest pieces of equipment in a fire protection system, but a poorly sized or misconfigured unit can mask leaks, trigger nuisance fire pump starts, and create wear that shortens the life of the main fire pump. Jockey pump sizing for fire protection systems is governed by NFPA 20,…<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"content-type":"","iawp_total_views":0,"footnotes":""},"categories":[21,209,23],"tags":[],"class_list":["post-43773","post","type-post","status-publish","format-standard","hentry","category-industry","category-market-insights-project-economics","category-tips-tricks","category-21","category-209","category-23","description-off"],"acf":[],"_links":{"self":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/43773","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/comments?post=43773"}],"version-history":[{"count":0,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/43773\/revisions"}],"wp:attachment":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/media?parent=43773"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/categories?post=43773"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/tags?post=43773"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}