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.
Безопасность и область применения: Пожарные насосы и их приводы относятся к оборудованию жизнеобеспечения. Работы с гидравлическими, электрическими, дизельными компонентами, топливом, аккумуляторами, под давлением, с вращающимся оборудованием, а также испытания и устранение неисправностей должны выполняться в соответствии с действующим утвержденным проектом, инструкциями производителя, применимыми стандартами и требованиями уполномоченного органа. Данное руководство описывает алгоритм принятия инженерных решений и не дает разрешения на внесение изменений на месте, обход защитных систем или эксплуатацию неквалифицированным персоналом.
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.
Практическая таблица решений
| 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 |
| Напорная характеристика насоса | Shows low-flow head capability | Manufacturer curve |
| Check valves | Leakage can cause cycling | Isolation and leak checks |
| Импульсная линия | 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.
Как это связано с оборудованием BORRAPUMP
BORRAPUMP поставляет насосное оборудование для проектов водоснабжения и пожаротушения. Ознакомьтесь с соответствующим Конфигурация продукта BORRAPUMP в качестве отправной точки, затем предоставьте требуемый расход, напор, источник воды, привод, мощность, средства управления, условия площадки, применимые требования, количество и пункт назначения. Окончательный выбор должен основываться на гидравлическом обосновании проекта и утвержденной проектной документации; данное руководство не утверждает, что одна каталожная компоновка подходит для любой юрисдикции или уровня риска.
Похожие руководства BORRAPUMP
- дизельные и электрические пожарные насосы
- выбор комплекта пожарного насоса
- Руководство по приемочным испытаниям NFPA 20
Авторитетные источники
Следующие источники определяют границы стандартов, контекст пожарной безопасности и принципы работы насосных систем, используемые в данном руководстве. Всегда применяйте редакцию и местные нормы, принятые для данного проекта.
- Страница разработки стандарта NFPA 20
- Ресурсы по насосным системам Министерства энергетики США
- Исследования Национального института стандартов и технологий (NIST) в области противопожарной защиты
Обучающее видео
Образовательный бэкграунд от Practical Engineering: Создают ли насосы давление или поток?. Видео поддерживает базовую инженерную концепцию и не заменяет проектно-специфические требования пожарной безопасности.
Часто задаваемые вопросы
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.
Контрольный список финальной проверки
Перед утверждением подтвердите гидравлическое обоснование, состояние источника воды, выбранную характеристику насоса, данные привода и контроллера, номинальные давления компонентов, компоновку арматуры, метод испытаний, доступ, дренаж, аварийную сигнализацию и процедуру восстановления. Устраните расхождения между чертежами и смонтированной системой. Во время пусконаладочных работ используйте откалиброванные приборы и фиксируйте давление на входе, давление на выходе, расход, частоту вращения, состояние привода, сигналы тревоги и отклонения в каждой требуемой точке. Храните принятые результаты вместе с документацией насосной станции, чтобы при последующих проверках можно было сопоставлять сопоставимые данные.