Systems & Components

WET SPRINKLER SYSTEM

Wet pipe systems are the simplest and most common type of sprinkler system. The piping contains water at all times and is connected to the water supply so that water discharges immediately from a sprinkler when it opens at a predetermined temperature.

Some of the components of this type of system include:

  • Tamper switches on the control valves, which will provide a trouble signal to the fire alarm panel if the valve is closed.
  • Flow switches on the system riser to detect flow conditions, and then send an alarm signal to the fire alarm panel if the system should begin flowing water.
  • An inspector’s test and drain is provided to check the actuation of the flow switch.
  • Water pressure gauges on the system riser to check the system water pressure.
  • A main drain to drain the system and allow for the replacement of sprinkler heads or repair of system piping.
  • Auxiliary drains to drain “trapped” portions of pipe.

ANTIFREEZE SPRINKLER SYSTEM

Antifreeze sprinkler systems are effectively wet pipe systems in that the piping contains fluid at all times and is connected to the water supply. Antifreeze solution, followed by water, discharges immediately from a sprinkler when it opens at a predetermined temperature.

Some of the components of this type of system include:

  • A reduced pressure principle back flow preventer provides a constant positive separation of the fluid in the sprinkler system from the potable water supply to which it is connected. A pressure differential relief valve is located between two check valves. This relief valve will discharge water due to minor check valve fouling and/or line pressure fluctuations.
  • An expansion tank receives any overflow of antifreeze solution as it expands in the system due to temperature fluctuation. Without it, the pressure in the system would build excessively because the fluid is trapped in a closed system.
  • Tamper switches on the control valves, which will generate a trouble signal to the fire alarm panel if the valve is closed.
  • Flow switches detect flow conditions, and then send an alarm signal to the fire alarm panel if the system should begin flowing antifreeze/water.
    An inspectors test and drain is provided to check the actuation of the flow switch.
  • Pressure gauges to check the system air/water pressure
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  • A main drain for allowing the system to be drained and allow for the replacement of sprinkler heads or repair of system piping. It is also used for the periodic testing of the system and backflow preventer.
  • Auxiliary drains to drain “trapped” portions of pipe.

PREACTION SPRINKLER SYSTEM

Preaction systems are similar to dry systems in that the piping is filled with air instead of water. However, unlike a dry system this air is not used to hold back the water from entering the piping. The air contained in the system is for supervisory purposes only. Should a sprinkler head open due to fire or accident, air will escape from the piping triggering a low air alarm on the fire alarm panel-no water will enter the system. For water to actually fill the systems piping, the activation of a heat or smoke detector is required. Once activated, an electric signal is sent to the preaction systems solenoid valve, which then opens allowing the main deluge valve to trip and fill the piping with water. Preaction systems can also be tripped manually at the valve by a manual release pull station. These types of systems are typically installed in high value areas such as computer rooms.

Some of the components of this type of system include:

  • Tamper switches on the control valves, which will provide a trouble signal to the fire alarm panel if the valve is closed.
  • Pressure switches on the deluge valve trim to detect flow conditions, and then send an alarm signal to the fire alarm panel if the system should begin flowing water.
  • Pressure switches on the system riser to send a trouble signal to the fire alarm panel if the systems air supply should drop below a preset level.
  • The trim of the preaction valve provides for the testing of the actuation signal without filling the piping with water.
  • Air and water pressure gauges on the system riser to check the system pressure.
  • A main drain for allowing the system to be drained and allow for the replacement of sprinkler heads or repair of system piping.
  • Auxiliary drains to drain “trapped” portions of pipe. These drains, drum drips, need to be monitored and maintained during colder months. maintenance schedule.

DRY SPRINKLER SYSTEM

Dry pipe systems are different from wet systems in that the piping is filled with air instead of water. This air pressure holds back the water from entering the system by using a special dry pipe valve. With the opening of a sprinkler head from heat, the pressure is decreased and the valve opens allowing the water to fill the piping and flow out the open head. Dry systems are typically installed where the piping is subject to freezing.

Some of the components of this type of system include:

  • Tamper switches on the control valves, which will provide a trouble signal to the fire alarm panel if the valve is closed.
  • Pressure switches on the dry pipe valve trim to detect flow conditions, and then send an alarm signal to the fire alarm panel if the system should begin flowing water.
  • Pressure switches are also on the system riser to send a trouble signal to the fire alarm panel if the systems air supply should not be adequate to keep the dry pipe valve from tripping open.
  • An inspector’s test and drain is located at the most remote location of the system to test the operation of the dry pipe valve, check the actuation of the pressure switch, and check the time it takes for water to reach the test location.
  • Air and water pressure gauges are on the system riser to check the system pressure.
  • A main drain is provided to drain the system and allow for the replacement of sprinkler heads or repair of system piping.
  • Auxiliary drains to drain “trapped” portions of pipe. These drains, drum drips, need to be monitored and maintained during colder months.