HD PREACTION SYSTEMS

Overview and working principle of HD Pre-Action Systems.
Pre-Action fire sprinkler system uses concept of having dry pipe sprinkler system. Water is withheld from sprinkler piping by a Pre-Action Valve. Pre-Action system generally requires two separate fire detection signals in order to operate. Thus the systems are effectively designed for water sensitive areas that require protection from inadvertent water flow into the sprinkler system piping. HD Pre-Pack is a pre-assembled Pre-Action System enclosed in a self-contained cabinet while HD Pre-Action systems can also be skid mounted. It is UL Listed and can be configured as single or double-interlock with several options. The system typically consists of HD deluge pre-action valve, riser check valve, pre-action trim, fail safe valve, butterfly valve, pressure switches, solenoid valve, air compressor and a releasing panel. Please refer to product catalogues for approval information, technical specifications and ordering information.
www.hdfire.com/pre-action-sys...

[@TheBenlueks]

imma learn this shit pass my coarse and never think about it again... thx!

[@mb-ig9rl]

hello can we use the preaction system with wet system, meaning with water filling the pipes after the valve?

[@ekoboy5024]

$ vh7mNjjorjkkNUIIIUYUIOOOLLOI❤😂😂😂😂😂😂😂😂

[@TheHdfire]

You can use single interlock wet pilot preaction system

[@rumildaolik4905]

good explanation. I still have some confusion with dry pipes system and preaction system. Dry pipe system contains compressed air. The air is released then water starts flowing once the system is triggered. With preaction system the pipe is also filled with air, then water comes into the pipe when the system is triggered.
So i do not see the difference. what is the main difference?

[@tythehedgechidnafox]

Ummm I know your comment is kinda old (probably found an answer to your inquiry by now), but a dry system will discharge water once all the compressed air is gone from the system
This is regardless of if the water is needed (ie actual fire, damaged sprinkler head)
A pre action system will only discharge water once two signals are received
Smoke detector and lack of compressed air in the pipes (ie bulb of a sprinkler head breaking)
This is to prevent unnecessary water damage in case of something just setting off the smoke alarm or if a sprinkler is damaged accidentally
In both of those cases, water isn’t needed and the system can be delayed or shut off before water is pumped out
It’s kinda like where there’s fire, there’s smoke but smoke doesn’t necessarily mean there’s a fire
Sorry if you already found the answer ^^;