กลับไปหน้าเครื่องคำนวณ

ระบบสปริงเกอร์ดับเพลิง (Sprinkler Hydraulic — NFPA 13)
คำนวณ Q × P ของระบบ wet-pipe sprinkler ด้วยวิธี back-calculation ตาม NFPA 13 §23 — เริ่มจาก sprinkler ปลายทาง (most-remote) ที่ residual 7 psi เดินย้อนขึ้นไปยัง branch, cross-main, riser จนถึง base พร้อมส่งค่า demand ต่อให้เครื่องคำนวณ fire-pump
หน่วยแสดงผล:
Repair garage, warehouse — density 0.20 × 1500 ft²
✓
NFPA 13 — Density Met delivered = 0.231 gpm/ft² vs required 0.200 (20 sprinklers in design area)
A. ความเสี่ยง (Hazard & Design Area — §19.3.3)
0.20 gpm/ft²
1500 ft²
Recommended sprinklers per branch = 1.2·√(A/S²) = 5 (§ 23.4.4.2 — for 10 ft spacing)
B. สปริงเกอร์ปลายสุด (Most-Remote Sprinkler S1)
NFPA 13 default: 7 psi (residential / light)
14.82 GPM
Q = K·√P = 5.6·√7.0
C. โครงสร้างเครือข่ายท่อ (Tree Topology)
demo: 3–5
demo: 4–6
D. ขนาดท่อ (Pipe Schedules)
C-factor ใช้ Hazen-Williams (NFPA 13 § 22.4). วัสดุ Steel ค่า new-pipe C = 120
Branch line
C used: 120
Cross-main
C used: 120
Riser
C used: 120
E. Hose Stream (§23.4.5)
Hazard preset: 250 GPM
F. ตัวเลือก (Options — ทั้งคลัง)
R1. Demand Summary @ Base of Riser
Total demand Q
597 GPM
Sprinkler 347 GPM + Hose 250 GPM
Pressure at base P
30.4 psi
= 21.40 m head
Residual @ S17.0 psi
Total elevation cost5.2 psi
Total friction cost18.2 psi
Density delivered0.231 gpm/ft²
Density required0.200 gpm/ft²
Density check✓ PASS
Pre-fills Q = 597 GPM, P = 30.4 psi, hazard = ord2 on the fire-pump-sizing page
R2. Sprinkler-by-Sprinkler Back-Calc (Branch 1)
Most-remote branch — by symmetry, other 3 branches mirror this exactly.
| Sprinkler | P (psi) | Q (GPM) | ΣQ (GPM) | Seg loss (psi) |
|---|---|---|---|---|
| B1-S1 | 7.00 | 14.82 | 14.82 | 0.30 |
| B1-S2 | 7.30 | 15.13 | 29.95 | 1.10 |
| B1-S3 | 8.40 | 16.23 | 46.18 | 2.46 |
| B1-S4 | 10.86 | 18.46 | 64.64 | 4.58 |
| B1-S5 | 15.44 | 22.01 | 86.64 | 7.88 |
| Branch tee | 23.32 | 86.64 | 86.64 | — |
R3. Pressure-Loss Split
Total = 30.4 psi at base of riser
Residual @ S17.00 psi (23.0%)
Branch friction16.32 psi (53.7%)
Cross-main friction1.80 psi (5.9%)
Riser friction0.09 psi (0.3%)
Elevation rise5.20 psi (17.1%)
R4. Pressure Profile Along Most-Remote Path
Pressure rises walking upstream — start at S1 (low) and grow toward base of riser
R5. Hydraulic Calc Summary Sheet (§ 27.2 format)
ใบสเปกระบบ Sprinkler — NFPA 13 (ดาวน์โหลด PDF)
เอกสารมาตรฐานพร้อมออก RFQ — ผลคำนวณ Q + P + density ใส่ให้แล้ว, ช่องเอกสาร/วัสดุ/อุปกรณ์แก้ไขได้
WORK PROJECT NAME:
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FIRE SPRINKLER SYSTEM — EQUIPMENT DATASHEET
DOCUMENT NO. :
REVISION :
BY
DEKENGINEER.COM
APPROVAL NOTE
APPROVEDAPPROVED WITH MINOR COMMENTSAPPROVED WITH MAJOR COMMENTSNOT APPROVED
RESUBMIT FOR APPROVAL BY
This approval does not relieve the contractor / vendor of his responsibility to meet the purchase-order conditions, referenced specifications, applicable codes and standards.
DATE
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| 0 | IFR | ||||
| REVISION | ISSUE DATE | PREPARED BY | CHECKED BY | APPROVED BY | REVISION STATUS |
| Customer PROJECT NO. : | DEKEN PROJECT NO. : | ||||
Page 2 / 3 | FIRE SPRINKLER SYSTEM SPECIFICATION SHEET NFPA 13-2022 §19 (hazard density-area) · §22 (Hazen-Williams) · §23 (back-calculation) · §23.4.5 (hose-stream) | Rev.0 | |
| Customer | Job Name | ||
| Location | Job No. | ||
| Item Name | Item No. | ||
| Type | No. of Req'd | ||
| Size | Manufacturer | ||
| OPERATING CONDITION | |||
| Building type | Operation | ||
| Occupancy | Installed Place | ||
| Hazard preset (NFPA 13 §19) | Area of application (ft²) | ||
| Density required (gpm/ft²) | Building area protected (m²) | ||
| Ceiling height (m) | Design demand | 597 GPM @ 30.4 psi | |
| Corr. / Eros. caused by | |||
| SPECIFICATION | |||
| Code Requirement | System type | ||
| Sprinkler model | Sprinkler temp rating | ||
| Pipe material spec | Flange / coupling code | ||
| Hanger / Support | Freeze protection | ||
| Alarm valve | FDC connection | ||
| Accessories | |||
| Spare Parts | |||
| Remarks | |||
Page 3 / 3 | FIRE SPRINKLER SYSTEM SPECIFICATION SHEET NFPA 13-2022 §19 (hazard density-area) · §22 (Hazen-Williams) · §23 (back-calculation) · §23.4.5 (hose-stream) | Rev.0 | |
| DESIGN BASIS (calculation inputs) | |||
| Hazard (NFPA 13 §19) | Ordinary Hazard Gp 2 (NFPA 13 §19.3.3.1.2) | Area of operation | 1500 ft² |
| Density required | 0.200 gpm/ft² | Remote sprinkler P_floor | 7.0 psi (default 7) |
| Sprinkler K-factor | 5.6 | Hose-stream allowance | 250 GPM (§23.4.5) |
| Topology (B × S) | 4 branches × 5 sprinklers | Spacing (on / between) | 10.0 ft / 10.0 ft |
| Pipe ID (branch / main / riser) | 1.380" / 4.026" / 6.065" | C-factor (HW) | 120 / 120 / 120 |
| HYDRAULIC PERFORMANCE (NFPA 13 §23 — computed) | |||
| Remote sprinkler S1 | 14.82 GPM @ 7.0 psi | Sprinklers in design area | 20 |
| Sprinkler Σ demand | 347 GPM | Hose stream added | 250 GPM (§23.4.5) |
| TOTAL demand @ base | 597 GPM (135.5 m³/h) | Pressure @ base | 30.4 psi (2.10 bar) |
| Density delivered | 0.231 gpm/ft² | Density required | 0.200 gpm/ft² |
| Loss split — branch / main | 16.3 / 1.8 psi | riser / fittings / elev. | 0.1 / 4.0 / 5.2 psi |
Density verdict PASS — density 0.231 gpm/ft² ≥ required 0.200 gpm/ft² (NFPA 13 §19.3.3) | |||
Pump handoff The total demand Q + P at the base of the riser is the design point for the fire-pump-sizing calculator (NFPA 20). Pump rated flow ≥ Q_total here; pump rated head ≥ P_total here + supply pressure losses; verify NPSHa per §4.16. | |||
| TESTING & REFERENCES | |||
| Hydrostatic test | Trip test | ||
References NFPA 13-2022 Standard for the Installation of Sprinkler Systems — §19.3.3 (density-area), §22.4 (Hazen-Williams + C-factor), §23 (back-calculation), §23.4.5 (hose-stream), §29 (commissioning); NFPA 25 (inspection, testing, and maintenance of water-based fire protection systems); FM Global DS 2-8N. เครื่องคำนวณช่วยตั้งต้น — back-calc จาก S1 ที่ remote ขึ้นต้นน้ำตาม NFPA 13 §23; วิศวกรผู้ออกแบบและผู้ติดตั้งที่ได้รับใบอนุญาตต้องตรวจสอบและรับรองก่อนออกเอกสาร. | |||
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ทำความเข้าใจ Sprinkler Hydraulic Calc (NFPA 13)
Indicative engineering results — DekEn implements published methods but is not a substitute for a licensed Professional Engineer. Verify against project data and applicable codes before construction, procurement, or RFQ.
ผลการคำนวณเป็นค่าเบื้องต้น — DekEn ใช้วิธีมาตรฐานที่อ้างอิงได้ แต่ไม่ใช่สิ่งทดแทนวิศวกรวิชาชีพ (PE) โปรดตรวจสอบกับข้อมูลโครงการและมาตรฐานที่เกี่ยวข้องก่อนนำไปก่อสร้าง จัดซื้อ หรือออก RFQ
ตรวจสอบแล้ว · Validated