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.
An toàn và phạm vi: Máy bơm phòng cháy chữa cháy và các thiết bị truyền động của chúng là thiết bị an toàn tính mạng. Công việc liên quan đến thủy lực, điện, dầu diesel, nhiên liệu, ắc quy, áp suất, thiết bị quay, thử nghiệm và khắc phục sự cố phải tuân theo thiết kế được phê duyệt hiện hành, hướng dẫn của nhà sản xuất, các tiêu chuẩn hiện hành và cơ quan có thẩm quyền. Hướng dẫn này giải thích lộ trình quyết định kỹ thuật; tài liệu này không cho phép thực hiện các thay đổi tại hiện trường, bỏ qua quy trình hoặc vận hành bởi nhân viên không đủ năng lực.
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.
Bảng quyết định thực tế
| 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 |
| Đường cong bơm | Shows low-flow head capability | Manufacturer curve |
| Check valves | Leakage can cause cycling | Isolation and leak checks |
| Đường ống cảm biến | 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.
Điều này liên quan như thế nào đến thiết bị BORRAPUMP
BORRAPUMP cung cấp thiết bị bơm kỹ thuật cho các dự án cấp nước và phòng cháy chữa cháy. Xem lại phần liên quan Cấu hình sản phẩm BORRAPUMP làm điểm khởi đầu, sau đó gửi lưu lượng, cột áp, nguồn nước, động cơ, công suất, hệ thống điều khiển, điều kiện hiện trường, các yêu cầu hiện hành, số lượng và điểm đến được yêu cầu. Lựa chọn cuối cùng phải sử dụng cơ sở thủy lực của dự án và bản trình duyệt được phê duyệt; hướng dẫn này không khẳng định rằng một bố trí trong catalogue phù hợp với mọi khu vực tàijurisdiction hoặc rủi ro.
Các hướng dẫn BORRAPUMP liên quan
- máy bơm chữa cháy diesel và máy bơm chữa cháy điện
- lựa chọn cụm bơm phòng cháy chữa cháy
- Hướng dẫn kiểm tra nghiệm thu NFPA 20
Tài liệu tham khảo có thẩm quyền
Các nguồn sau đây thiết lập ranh giới tiêu chuẩn, bối cảnh an toàn phòng cháy chữa cháy và các nguyên tắc hệ thống bơm được sử dụng trong hướng dẫn này. Luôn áp dụng phiên bản và quy chuẩn địa phương được chấp thuận cho dự án.
- Trang phát triển tiêu chuẩn NFPA 20
- Tài nguyên hệ thống máy bơm của Bộ Năng lượng Hoa Kỳ
- Nghiên cứu phòng cháy chữa cháy của NIST
Video giáo dục
Nền tảng giáo dục bởi Practical Engineering: Máy bơm tạo ra áp suất hay lưu lượng?. Video hỗ trợ cho khái niệm kỹ thuật cơ bản và không thay thế các yêu cầu phòng cháy chữa cháy cụ thể của dự án.
Các câu hỏi thường gặp
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.
Danh sách kiểm tra xác minh cuối cùng
Trước khi phê duyệt, hãy xác nhận cơ sở thủy lực, điều kiện nguồn nước, đường cong bơm đã chọn, dữ liệu bộ truyền động và bộ điều khiển, định mức áp suất của các bộ phận, bố trí van, phương pháp thử nghiệm, lối đi, hệ thống thoát nước, cảnh báo và quy trình khôi phục. Giải quyết các khác biệt giữa bản vẽ và hệ thống thực tế đã lắp đặt. Trong quá trình chạy thử, hãy sử dụng các thiết bị đã hiệu chuẩn và ghi lại áp suất hút, áp suất xả, lưu lượng, tốc độ, tình trạng bộ truyền động, cảnh báo và các quan sát bất thường tại mọi điểm yêu cầu. Lưu giữ các kết quả đã được chấp nhận cùng với hồ sơ phòng bơm để các lần kiểm tra sau có thể so sánh các yếu tố tương đương.