Size a jockey pump to replace normal system leakage and small pressure losses without meeting sprinkler or hose demand and without repeatedly starting the main fire pump. Determine realistic leakage, system volume and pressure behavior, required pressure, acceptable run time, and the coordinated start-stop sequence. Select a small pump whose curve can reach the intended stop pressure at low flow, then verify that a genuine fire demand produces enough pressure decay to start the main fire pump. Keep the calculation and acceptance record with the final project documents so future tests use the same basis.
Seguridad y alcance: Las bombas contra incendios y sus motores son equipos de seguridad para la vida. Los trabajos hidráulicos, eléctricos, diésel, de combustible, de baterías, de presión, de equipos rotativos, de prueba y de deficiencias deben seguir el diseño aprobado vigente, las instrucciones del fabricante, las normas aplicables y la autoridad competente. Esta guía explica la ruta de decisiones de ingeniería; no autoriza cambios en campo, derivaciones ni la operación por personal no calificado.
Define the jockey pump's job
It maintains normal system pressure after small losses. It is not a substitute for the main fire pump and should not mask material leakage. Treat this as a system condition rather than an isolated component choice. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Estimate normal leakage
Use maintenance history, measured pressure decay, known valve and device leakage, and system condition. Investigate abnormal leakage instead of permanently oversizing the jockey pump. The most useful evidence is measured or approved project data, not a copied rule of thumb. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Understand system volume
Large networks, tanks, and trapped air affect how quickly pressure changes. System compressibility influences cycling but does not create a universal sizing ratio. Review this condition at normal, test, and credible abnormal states before procurement. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Set the required pressure range
The jockey pump must reach the approved stop pressure while its start point remains above the main fire pump start point in the coordinated sequence. The design team should turn this point into a traceable calculation or drawing note. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Tabla de decisiones práctica
| Sizing input | Effect on jockey pump | How to verify |
|---|---|---|
| Normal leakage | Sets required makeup flow | Pressure-decay test and history |
| System volume | Affects pressure-change rate | Drawings and field behavior |
| Target pressure | Sets required head | Approved pressure sequence |
| Curva de la bomba | Shows low-flow head capability | Manufacturer curve |
| Check valves | Leakage can cause cycling | Isolation and leak checks |
| Línea de detección | Controls measured pressure | Field route and valve position |
Check the pump curve
Select against low-flow, high-head operation. Confirm minimum stable operation, shutoff head, motor load, and manufacturer limitations. Treat this as a system condition rather than an isolated component choice. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Limit short cycling
Review check-valve leakage, pressure-tank function where used, sensing line location, system volume, and the gap between start and stop settings. The most useful evidence is measured or approved project data, not a copied rule of thumb. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Coordinate controls and alarms
Keep the sensing line independent and correctly arranged, protect it from blockage or trapped air, and document controller modes and alarm response. Review this condition at normal, test, and credible abnormal states before procurement. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Commission the sequence
Create a controlled small pressure loss, verify jockey start and stop, then create the approved larger demand and verify main pump start without delay. The design team should turn this point into a traceable calculation or drawing note. Identify the source of every input, the unit used, the operating condition it represents, and the person responsible for approval. If information is preliminary, mark the assumption and test how the decision changes at a conservative boundary. This prevents a neat calculation from hiding an uncertain water level, pressure, valve position, driver condition, or simultaneous demand.
For jockey pump sizing, verify this section against the selected pump curve, the actual site arrangement, manufacturer instructions, and the current requirements accepted by the authority having jurisdiction. Check the installed condition as well as the drawing because pipe routes, elevations, supports, controls, and access often change during construction. Record the result in a form that can be repeated during commissioning and later inspection. Do not change a safety-critical setting or isolate fire protection without the approved impairment and restoration process.
Cómo se relaciona esto con el equipo BORRAPUMP
BORRAPUMP suministra equipos de bombeo diseñados para proyectos de agua y protección contra incendios. Revise el correspondiente configuración del producto BORRAPUMP como punto de partida, luego presente el flujo requerido, la carga, la fuente de agua, el motor, la potencia, los controles, las condiciones del sitio, los requisitos aplicables, la cantidad y el destino. La selección final debe utilizar la base hidráulica del proyecto y la presentación aprobada; esta guía no afirma que una disposición de catálogo se adapte a todas las jurisdicciones o riesgos.
Guías relacionadas de BORRAPUMP
- bombas contra incendios diésel frente a eléctricas
- selección de equipo de bombeo contra incendio
- Guía de pruebas de aceptación NFPA 20
Referencias autorizadas
Las siguientes fuentes establecen el límite normativo, el contexto de seguridad contra incendios y los principios del sistema de bombas utilizados en esta guía. Aplique siempre la edición y la adopción local aceptadas para el proyecto.
- Página de desarrollo de la norma NFPA 20
- Recursos sobre sistemas de bombas del Departamento de Energía de EE. UU.
- Investigación sobre protección contra incendios del NIST
Video educativo
Antecedentes educativos por Practical Engineering: ¿Las bombas crean presión o caudal?. El video respalda el concepto de ingeniería subyacente y no reemplaza los requisitos de protección contra incendios específicos del proyecto.
Preguntas frecuentes
Can I size a jockey pump as a percentage of the fire pump?
Do not rely on a percentage alone. Use actual leakage, system pressure behavior, the jockey curve, and approved criteria.
Why does the jockey pump short-cycle?
Possible causes include leakage, check-valve backflow, small system volume, trapped air, pressure-tank problems, or narrow settings.
Should the jockey pump handle sprinkler flow?
No. A fire demand must start the main fire pump according to the approved sequence.
Can an oversized jockey pump delay the main pump?
It can mask a growing demand or create poor control behavior, so size and test the complete sequence.
Lista de verificación de verificación final
Antes de la aprobación, confirme la base hidráulica, la condición de la fuente de agua, la curva de la bomba seleccionada, los datos del motor y del controlador, las presiones nominales de los componentes, la disposición de las válvulas, el método de prueba, el acceso, el drenaje, las alarmas y el procedimiento de restauración. Resuelva las diferencias entre los planos y el sistema instalado. Durante la puesta en marcha, utilice instrumentos calibrados y registre la presión de succión, la presión de descarga, el caudal, la velocidad, el estado del motor, las alarmas y las observaciones anormales en cada punto requerido. Guarde los resultados aceptados junto con los registros de la sala de bombas para que las inspecciones posteriores comparen elementos equivalentes.