Dry pipe wet pipe sprinkler systems…. what’s the difference?

The difference is air.

Not all fire sprinkler systems are the same. When choosing the right system for your facility, you may have some questions. More people are familiar with wet fire sprinkler systems. In wet pipe systems, the overhead sprinkler piping is filled with water under pressure. When a fire causes one or more of the connected sprinklers to activate, water immediately discharges from the sprinkler head.

Wet pipe systems are the most common type of fire sprinkler system and the simplest. They are common in multi-unit residential buildings. Due to their simplicity, they are very reliable and often require less installation and maintenance.

At the same time, business owners may opt for a dry pipe system. Such systems are popular where the temperatures reach below 40 degrees F. Storage facilities and garages, or manufacturing and industrial facilities.

Dry pipe fire sprinkler systems NYC property managers need are available from Master Fire. Dry pipe systems do not have water in the direct non-heated sprinkler piping, but only pressurized air or nitrogen. The pressurized air holds back the water supply at a main dry-pipe valve. When a fire occurs and the sprinkler activates, the air pressure drops and the main dry-pipe valve opens to release the water into the piping system to discharge from the sprinklers.
They, like the wet pipe systems mentioned above, are required to undergo regular testing including a 5 year pressure test.

In the case of the former, a siamese connection test needs to be performed every 5 years. In respect to the dry pipe system, this is called a trip valve test. Dry pipe systems need to be performed every 5 years as well.

These fire sprinkler systems are thus designed for environments with freezing temperatures like walk-in refrigerators, loading docks, and warehouses. Because of its special air pressure needs and other components, dry pipe sprinklers are more complex than wet fire sprinklers and are thus more costly to install and maintain.

Because water must travel from the valve to the piping and sprinklers, there can be a delay of up to 60 seconds in fire suppression. Dry fire sprinkler systems also have certain design restrictions as to their individual system size and thus can make additions to the system very difficult or not possible. These systems can, however, be an addition to a larger wet pipe sprinkler system and just used in the environments that see freezing temperatures.

Master Fire Mechanical is your one stop fire sprinkler system design resource. We are a turn-key solution for fire sprinkler system design, installation, testing, inspections, and maintenance. Here’s another page that goes into the subject in more detail https://masterfiremechanical.com/fire-systems-nyc/fire-sprinkler-installation-nyc/

Check out this video on our YouTube Channel about Dry Pipe Wet Pipe Fire Sprinkler System Inspection and Testing at https://www.youtube.com/watch?v=TC_FwDxkPYY

When it comes to Dry Pipe Wet Pipe Sprinkler Systems, call Master Fire at (917) 580-6330