Dry Flange Alarm Check Valve
Alarm check valve – core of wet pipe sprinkler systems. Prevents reverse flow, triggers water motor gong. Retard chamber stops false alarms from pressure changes.
Fujian Haijing Fire Fighting Equipment Co., Ltd. is one of the leading manufacturers and suppliers of dry flange alarm check valve in China, also supports customized service. Please feel free to wholesale cheap dry flange alarm check valve from our factory.
What Is a Dry Type Alarm Check Valve?
It's an alarm check valve designed for places where water would freeze. Unheated warehouses. Parking garages. Attics. Cold storage. Outdoor canopies. Anywhere the temperature drops below freezing.
In a wet system, water sits in the pipes all the time. If the pipes freeze, they burst. In a dry system, the pipes are filled with compressed air or nitrogen – not water. The water stays at the valve, held back, waiting .
The dry type alarm check valve is the gatekeeper. It holds the water back with air pressure. When a sprinkler opens, the air escapes. The pressure drops. The valve opens. Water rushes in. The fire gets wet. The system works.
| Size | DN65 | DN80 | DN100 | DN125 | DN150 | DN200 | DN250 | DN300 |
| Height of Alarm Valve (mm) | 260 | 342 | 430 | 530 | 630 | 680 | ||
| Outside Diameter of Flange (mm) | 185 | 200 | 220 | 250 | 285 | 340 | 405 | 460 |
| Diameter Between Flange Screw Hole (mm) | 145 | 160 | 180 | 210 | 240 | 295 | 355 | 410 |
| Diameter of Flange Holes (mm) | 4 | 8 | 12 | |||||
| Quantity of Screw Hole | 18 | 22 | 26 | |||||
Where Do You Use a Dry Type Alarm Valve?
- Unheated warehouses. Pipes in the ceiling would freeze if they had water in them. Dry system keeps them safe.
- Parking garages. Open to the cold. Sprinkler pipes need freeze protection.
- Attics and crawlspaces. Unheated. Pipes would burst in winter.
- Cold storage and refrigerated warehouses. Below freezing all year. Dry system is the only option .
- Outdoor canopies. Gas stations, loading docks. Pipes exposed to the elements.
- Seasonal buildings. Cabins, vacation homes. Heat is off in winter. Pipes would freeze.
- Commercial buildings in cold climates. Anywhere the building isn't heated year-round .
If the space isn't heated, you need a dry system. And a dry system needs a dry alarm valve.
Common Problems and Fixes
Problem: The valve trips for no reason – false alarm.
Fix: Air pressure dropped below the trip threshold. The system has a leak. Find and fix the air leak. Check the air compressor.
Problem: The valve won't trip when a sprinkler opens.
Fix: The air pressure is too low – the valve might already be partially open. Or the differential ratio is wrong. Check air pressure – should be at correct ratio to water pressure. Check the clapper – may be stuck.
Problem: Water leaks past the clapper.
Fix: Rubber gaskets are worn or debris on the seats. Drain the system. Inspect the clapper. Clean the seats. Replace the gaskets.
Company Information
Contact Information
Send us your enquiry, we will reply In 24 Hours!
Siya Huang
WhatsApp/WeChat: +86 15102989485
E-mail: sales07@sajingfire.com
Add: Maosheng RD., Fumao Economic Zone, Nan'an City, Fujian, China, 362300
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