Dormer1975
Mechanical
- Aug 31, 2007
- 25
The situation I'm dealing with is a unique one. I'm not sure it's specifically my responsibility to address this issue, but I'm involved. It's in a remote location. I'm hoping someone reading this has had some experience with this.
We are installing a fire sprinkler system in a warehouse protecting a 'caustic material' in 55 gallon drums. In the event of a fire, there exists the scenario where fire sprinkler water and 'caustic material' from those drums could co-mingle. That co-mingled water must be prevented from reaching the outdoor environment. The general contractor designed the floors to slope to drains that route to the outdoor loading dock (the ramp that trucks back down to load/unload product). In essence, this loading dock is acting as a swimming pool to contain the co-mingled water.
I determined the volume available in the loading dock ramp area for containment. Then, I determined the volume of water that the sprinkler system would emit under the Design Criteria situation. As the containment is outdoors, 25-year Storm rainfall also had to be accounted for.
The issue is the drain in the loading dock. This drain vacates storm water, etc so it must normally remain open to flow to the catch basin. We proposed placing a valve in the piping between the loading dock drain and the catch basin in some sort of vault. It would normally remain open. The intention is to close this valve in the event of a fire to hold the co-mingled water in the loading dock to be dealt with at a later time. The idea is that when a flow switch on the sprinkler system activates, it sends a signal to this valve to shut. Also, there would be a manual pull station that could also send a signal to the valve to close. Worst case scenario, someone could open the vault and manually close the valve.
Here's the problem...we can't find a valve that will function the way we need it...normally open that would close upon activation (fail-close). We requested a fail-close (energized to open) valve so that if the building lost power, the valve would shut as a failsafe. That seems to be the linchpin or crux of the problem. We've reached out to 2 valve companies and they say that type of valve requires supervisory pressure to close. (They mentioned cylinder actuators that require 80psi of air pressure to operate or utilizing some type of battery backup system.) We want it to close before any co-mingled water gets to it. Additionally, getting a valve that's UL/FM approved is a problem as well even among the valves that require supervisory pressure. The drain is located at the bottom of the loading dock. The valve is in a vault outside the loading dock.
Has anyone had any experience with containment situations like this? Any suggestions would be greatly appreciated.
You may think, "why is the sprinkler contractor involved with this?" Well, the general contractor we are working for asked us to help address this issue and the civil engineer on the project isn't much help.
We are installing a fire sprinkler system in a warehouse protecting a 'caustic material' in 55 gallon drums. In the event of a fire, there exists the scenario where fire sprinkler water and 'caustic material' from those drums could co-mingle. That co-mingled water must be prevented from reaching the outdoor environment. The general contractor designed the floors to slope to drains that route to the outdoor loading dock (the ramp that trucks back down to load/unload product). In essence, this loading dock is acting as a swimming pool to contain the co-mingled water.
I determined the volume available in the loading dock ramp area for containment. Then, I determined the volume of water that the sprinkler system would emit under the Design Criteria situation. As the containment is outdoors, 25-year Storm rainfall also had to be accounted for.
The issue is the drain in the loading dock. This drain vacates storm water, etc so it must normally remain open to flow to the catch basin. We proposed placing a valve in the piping between the loading dock drain and the catch basin in some sort of vault. It would normally remain open. The intention is to close this valve in the event of a fire to hold the co-mingled water in the loading dock to be dealt with at a later time. The idea is that when a flow switch on the sprinkler system activates, it sends a signal to this valve to shut. Also, there would be a manual pull station that could also send a signal to the valve to close. Worst case scenario, someone could open the vault and manually close the valve.
Here's the problem...we can't find a valve that will function the way we need it...normally open that would close upon activation (fail-close). We requested a fail-close (energized to open) valve so that if the building lost power, the valve would shut as a failsafe. That seems to be the linchpin or crux of the problem. We've reached out to 2 valve companies and they say that type of valve requires supervisory pressure to close. (They mentioned cylinder actuators that require 80psi of air pressure to operate or utilizing some type of battery backup system.) We want it to close before any co-mingled water gets to it. Additionally, getting a valve that's UL/FM approved is a problem as well even among the valves that require supervisory pressure. The drain is located at the bottom of the loading dock. The valve is in a vault outside the loading dock.
Has anyone had any experience with containment situations like this? Any suggestions would be greatly appreciated.
You may think, "why is the sprinkler contractor involved with this?" Well, the general contractor we are working for asked us to help address this issue and the civil engineer on the project isn't much help.