CA-FIRE · Water Flow Indicator Series
Saddle-Type Water Flow Indicator
ZSJZ · Ductile Iron Saddle · DN50–DN300 · 1.6 MPa · Dual NC Contact · IP66
Model: ZSJZ DN50–DN300 · Ductile Iron
Saddle-Type Water Flow Indicator for Fire Sprinkler Systems
The CA-FIRE ZSJZ saddle-type water flow indicator is the flagship paddle-vane flow detector for automatic wet-pipe fire sprinkler systems. Designed for saddle mounting on existing steel pipework, it detects sprinkler activation the moment water begins to flow and sends a dual-contact alarm signal to the fire alarm control panel — no pipe cutting, welding or threading required for installation.
DN50 to DN300 — one model family covers every sprinkler pipe size from branch to riser
1.6 MPa rated working pressure (230 psi / 16 bar)
Dual NC contacts — one to FACP, one to BMS / auxiliary system
Hall-effect micro-switch — sealed, long service life, no mechanical wear
IP66 enclosure with M20×1.5 cable gland, corrosion-resistant
Retard delay ignores pressure surges, eliminates false alarms
Key Features
Why the ZSJZ Saddle-Type Is the Industry Standard
Saddle-mount paddle indicators dominate the fire sprinkler market for one reason: they install on any existing steel pipe without breaking the pipework. Every CA-FIRE ZSJZ unit is engineered around that installation philosophy — making it the fastest flow indicator to fit, commission and maintain across the DN50–DN300 range.
Retrofit-Friendly Saddle Mount
U-bolt saddle clamps directly onto the outside of steel sprinkler pipe. Only a small circular hole is drilled into the pipe for the paddle vane — no cutting, welding or re-threading required.
Hall-Effect Micro-Switch
Sealed Hall-effect switch replaces mechanical reed switches for dramatically longer service life and consistent actuation after thousands of flow cycles.
Dual NC Contact Output
Two independent NC contact pairs — one wires directly to the fire alarm control panel (FACP), the other feeds a BMS or auxiliary monitoring system with no additional relays.
Built-in Retard Delay
Integrated delay on actuation filters out short pressure surges from water-hammer and system top-up, eliminating false alarms without masking real sprinkler activation.
EPDM Saddle Gasket
EPDM rubber gasket between saddle and pipe provides watertight seal across the drilled opening. Compatible with fresh water, foam-water mixture and stabilised glycol systems.
IP66 Weatherproof Head
Fully weatherproof IP66-rated housing with M20×1.5 cable gland. Suitable for outdoor pump rooms, roof tanks, car parks and exposed sprinkler risers.
Technical Specifications
Full Technical Specifications
Two reference tables. The first lists the unit's electrical, mechanical and environmental parameters shared across all sizes. The second lists dimensional and flow parameters that vary with pipe DN.
Table 1 — Electrical & Mechanical
| Parameter | Specification |
|---|---|
| Model | ZSJZ (DN50–DN300) |
| Body material | Ductile iron, epoxy-coated (standard) · SS304 optional |
| Paddle material | Stainless steel flexible vane |
| Gasket material | EPDM rubber |
| Working pressure | 1.6 MPa (16 bar / ~230 psi) maximum |
| Media temperature | 4°C to 70°C |
| Ambient temperature | −10°C to +55°C |
| Switch type | Hall-effect micro-switch, sealed |
| Contact form | Two sets of normally closed (NC) contacts |
| Contact rating | DC24V 1A / AC220V 0.5A |
| Enclosure rating | IP66 |
| Cable entry | M20 × 1.5 threaded cable gland |
| Retard delay | Adjustable, 0 – 90 seconds (factory default ~20 s) |
| Mounting orientation | Horizontal or vertical pipe (head upright) |
| Standards | Manufactured to GB 16280; compatible with NFPA 13, UAE Civil Defence, SASO, SIRIM, SABS installation practice |
Table 2 — Dimensions & Alarm Flow by Pipe Size
| Pipe DN | Drilled Hole Size | Working Pressure | Alarm Flow Rate | Contact Rating | Contact Form |
|---|---|---|---|---|---|
| DN50 | 40 mm | 1.6 MPa | 15 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN65 | 40 mm | 1.6 MPa | 15 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN80 | 50 mm | 1.6 MPa | 18 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN100 | 50 mm | 1.6 MPa | 22 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN125 | 50 mm | 1.6 MPa | 27 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN150 | 50 mm | 1.6 MPa | 30 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN200 | 84 mm | 1.6 MPa | 33 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN250 | 84 mm | 1.6 MPa | 35 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
| DN300 | 84 mm | 1.6 MPa | 37.5 L/min | DC24V 1A / AC220V 0.5A | 2× NC |
Alarm flow rate represents the minimum sustained flow required to actuate the switch after the retard delay. Values equivalent to flow from at least one open sprinkler head.
Installation
Installation Procedure — 4 Steps
The ZSJZ saddle-type water flow indicator is designed to install in under 15 minutes on an empty / drained pipe. Always follow NFPA 13 (or your local equivalent) clearance rules and ensure the system is depressurised before drilling.
1
Drain & Mark Pipe
Isolate and drain the sprinkler branch. Mark the drilling position at least 1× pipe diameter from any fitting and with adequate straight pipe run above and below.
2
Drill & Clean Hole
Using a hole saw, drill the correct opening — 40 mm for DN50/DN65, 50 mm for DN80–DN150, or 84 mm for DN200–DN300. Deburr and clean the rim.
3
Fit Saddle & Tighten
Align the EPDM gasket and saddle over the drilled hole with the flow-direction arrow pointing downstream. Tighten U-bolt nuts evenly, alternating side to side.
4
Wire & Test
Route cables through the M20 gland, terminate NC contacts to the FACP and BMS. Re-pressurise, run an inspector's test valve flow and confirm alarm signal at the panel.
Commercial Terms
Factory-Direct Export Terms
CA-FIRE ships the ZSJZ saddle-type water flow indicator to 60+ countries. Standard commercial terms below; contact our sales team for project pricing, LC terms, CIF quotations or OEM / private-label enquiries.
MOQ
50 pcs
Lead Time
15–20 days
FOB Port
Ningbo, China
Payment
30% TT + 70% · L/C at sight
Packing
Export carton + wooden pallet
OEM / Private Label
Yes, from 200 pcs
Applications
Typical Applications for ZSJZ Saddle Type
High-Rise Residential & Commercial
Warehouses & Logistics
Shopping Malls & Retail
Hotels & Hospitality
Hospitals & Healthcare
Car Parks & Basements
Schools & Public Buildings
Industrial & Manufacturing
FAQ
Frequently Asked Questions
What is a saddle-type water flow indicator?
A saddle-type water flow indicator mounts on the outside of a sprinkler pipe using a U-bolt saddle clamp, with only a small hole drilled into the pipe for the paddle vane to pass through. It is the most common type of flow indicator for wet-pipe fire sprinkler systems because it can be installed on existing pipework without cutting, threading or welding the pipe. CA-FIRE ZSJZ covers DN50 through DN300.
What hole size is drilled into the pipe for a saddle-type flow indicator?
The drilled hole size depends on pipe DN: 40 mm for DN50/DN65, 50 mm for DN80/DN100/DN125/DN150, and 84 mm for DN200/DN250/DN300. A hole saw is used to cut a clean circular opening centred under the saddle after clamping. Refer to Table 2 above for full per-size details.
How is the saddle-type flow indicator wired to the fire alarm control panel?
CA-FIRE saddle-type water flow indicators output two sets of normally closed (NC) contacts rated DC24V 1A or AC220V 0.5A. One contact pair wires directly to an initiating device circuit (IDC) or addressable module of the fire alarm control panel to report sprinkler activation. The second contact pair can be used for a BMS feed or auxiliary monitoring. Cable entry is via an M20×1.5 threaded cable gland on the weatherproof IP66 head.
Does the saddle-type indicator work with Victaulic grooved pipe?
Yes. The saddle clamp fits the outside diameter of steel pipe regardless of whether the pipe ends are flanged, threaded, or grooved for Victaulic couplings. The indicator itself is independent of end connection type because it mounts between joints on the pipe run.
What is the MOQ and lead time for saddle-type water flow indicators?
Standard minimum order quantity is 50 pieces. Standard lead time is 15 to 20 working days after receipt of down payment, FOB Ningbo. For large projects (500+ pieces) lead time may extend to 25 to 30 days; please confirm the schedule with our sales team when placing the order.
Can the saddle-type water flow indicator be installed horizontally and vertically?
Yes, the saddle-type flow indicator can be installed on horizontal or vertical pipe runs. The arrow cast into the saddle body must point in the direction of water flow. The indicator head must be positioned upright (not upside down) so the paddle pivot operates freely and the cable gland drains correctly.
Request a Quote for Saddle-Type Water Flow Indicator
Contact CA-FIRE for pricing, MOQ, lead time, wiring diagrams, submittal datasheets or OEM enquiries on the ZSJZ saddle-type range.
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