I don't know if this is something the forum can help with, or if I need the EoR to weigh in. Between writing my third RFI and playing phone tag with the EoR and GC I am now behind schedule on my permit drawings, and if I cant figure something out soon it could impact the project schedule. So I figured I would ask here to see if anyone could offer advice.
I am currently working on a college project that has a private domestic loop on campus. The new building that I am designing the sprinkler system for will have a supply line from the city main entering, a quadruplex (primary) and triplex (secondary) Vertical Multi Stage Domestic Water Booster Pump Skids, and associated valving, backflow, etc. This will all be installed by the plumber, and the sprinkler system will tap off the discharge manifold with its own backflow.
I have all of the product information and pipe routing from the plumber to consider in my calculations. The big hangup I have is the pump curve. Rather than a curve it is an area, and there is no data sub 500gpm so I am not certain what boost to use for my light hazard and 4 residential head calculations per NFPA 13. I have reached out to the EoR, but the response was to only consider the secondary booster pump, and to use the top of the area as the curve, the lack of data below 500gpm was not addressed.
My main concern is the Min. Flow of 150gpm designated on the performance curve of the individual pump. Would the pump activate at a low flow, like a light hazard calculation reduced to 900sqft? That is only 90gpm plus losses. The sequencing from the product sumbittal says the lead pump starts on a 5 second delay after a 5psi drop below set pressure so it sounds like it would regardless of flow.
My second concern is would I just use the pump curve for an individual pump for these lower flow calculations? If the lead pump never exceeds it BOP then the lag pump will never start. I can use the performance "curve" (top of the area) per the EoRs direction for the standpipe calculation. (750gpm for two standpipes)
My third concern, and unrelated to the pump performance, is there is no bypass from pump suction to pump discharge even though the city water supply is of some value for fire suppression.
Does anyone have experience with these kinds of pumps? Even if all you can do is help me come up with more pointed questions for the EoR, they don't seem to understand what I am trying to get at.
Huey
I am currently working on a college project that has a private domestic loop on campus. The new building that I am designing the sprinkler system for will have a supply line from the city main entering, a quadruplex (primary) and triplex (secondary) Vertical Multi Stage Domestic Water Booster Pump Skids, and associated valving, backflow, etc. This will all be installed by the plumber, and the sprinkler system will tap off the discharge manifold with its own backflow.
I have all of the product information and pipe routing from the plumber to consider in my calculations. The big hangup I have is the pump curve. Rather than a curve it is an area, and there is no data sub 500gpm so I am not certain what boost to use for my light hazard and 4 residential head calculations per NFPA 13. I have reached out to the EoR, but the response was to only consider the secondary booster pump, and to use the top of the area as the curve, the lack of data below 500gpm was not addressed.
My main concern is the Min. Flow of 150gpm designated on the performance curve of the individual pump. Would the pump activate at a low flow, like a light hazard calculation reduced to 900sqft? That is only 90gpm plus losses. The sequencing from the product sumbittal says the lead pump starts on a 5 second delay after a 5psi drop below set pressure so it sounds like it would regardless of flow.
My second concern is would I just use the pump curve for an individual pump for these lower flow calculations? If the lead pump never exceeds it BOP then the lag pump will never start. I can use the performance "curve" (top of the area) per the EoRs direction for the standpipe calculation. (750gpm for two standpipes)
My third concern, and unrelated to the pump performance, is there is no bypass from pump suction to pump discharge even though the city water supply is of some value for fire suppression.
Does anyone have experience with these kinds of pumps? Even if all you can do is help me come up with more pointed questions for the EoR, they don't seem to understand what I am trying to get at.
Huey
