Due to its resistance to freezing, the wet alarm valve is only suitable for systems above +4 °C. Alarm check valves and flow detectors are used to detect mechanical and electronic alarm signals.

	Wet alarm valve body Size: 3", 4", 6", 8" Assembly type: flange x flange, flange x groove, groove x groove Assembly direction: vertical Working pressure: 250 psi Certification: FM, UL		Delayer In wet sprinkler systems, retarders are used to prevent false alarms from panic. Material: stainless steel Connection: 3⁄4” BSPT Working pressure: 250 psi Certification: FM, UL
	Hydraulic alarm The water alarm is used for fire alarms in wet sprinkler systems. It acts after the retarder and is used in conjunction with an alarm valve. Filters are usually used before the water alarm. Material: aluminum alloy Connection: 3⁄4” BSPT Working pressure: 250 psi Certification: FM, UL		Pressure Switch The pressure switch is used to detect pressure changes to alert the system. Can be divided into air pressure switch and water pressure switch two types. Suitable for indoor and outdoor use. The pressure adjustment range is 4-20 psi. The factory setting pressure adjustment range is 4-8 psi. Working temperature: -40 °C ~ +71 °C Connection: 3⁄4” BSPT Working pressure: 1⁄2” NPT Certification: FM, UL, ULC

       When the sprinkler head (1) is opened, the water flow opens the valve flap (2) and flows into the pipeline (3), first passing through the delay chamber (4), so that the pressure switch (6) therein receives the fire alarm signal, and then the hydraulic alarm bell (5) Issue a mechanical alarm to ring.