Can a wafer check or grooved check valve be installed directly on a fire pump discharge flange?
I've found they affect the pump performance by 3 to 8 psi. When testing we found this true and moved it by a foot. The pump didn’t hit its curve and was fairly new. Shouldn’t NFPA 20 or manufacturers be aware of this? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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Has anyone here ever done a green points calculation for the benefit of having a flow meter on a fire pump and rat racing back to suction rather than waste?
I’ve heard many talk of this and how conscious they are of our effort to save water, but I’m wondering if anyone has ever submitted applications, calculated savings, or presented evidence. I’d also be interested in local or regional purveyor requirements on waste, reclamation, and disposal, if there are any. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe During a fire event, the pressure in a sprinkler system drops, and the jockey pump starts but cannot make up the pressure loss. Then, the electric fire pump kicks in.
Should the jockey still be running, or stop? Same for electric and diesel: should they operate together if the pressure still goes down and the electric pump cannot make the pressure up? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe To comply with NFPA-20, the fire pump suction must have at least 10 pipe diameters from the pump flange to the elbow or tee. According to Section 4.16.6.3, the pipe can be horizontal or vertical.
Does the vertical pipe have to be at a 90-degree angle, or will a 45-degree angle be acceptable because that's the only way it can be installed? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can a fitting (a 90-degree elbow) from a fire ductile iron water line be under the footing, which turns the pipe up into the Fire Pump room?
In other words, the pipe feed comes from a water tank underground, then turns up with a 90 under the building footing and the pipes through the footing. Is this acceptable? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a number of apartment buildings, 4-5 stories in height, with fire pumps serving the standpipes coming towards their end-of-life.
Is there a code requirement to re-evaluate the water supply when replacing a pump in a like-for-like scenario? Of course, this building has no existing fire protection records or placards to reference. Thanks! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can a fire pump room, properly built with only a fire pump and domestic water in it, have the fire pump electrical service meter in the fire pump room?
The local utility is permitting it. This specific example has it meeting reliable power, so there is no emergency feed that could be affected by the meter blowing out. If the meter goes, so does the pump power. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Our high-rise facility consists of apartments, condominiums, retail on the bottom floor, restaurant tenants on the top floor, and (3) levels of underground parking. We are 9 stories tall out of the ground.
They have great water pressure at the site with 140 static and 118 residual, flowing about 1,900 GPM, but with our floor-to-floor distances, I cannot get 100 PSI at the top of my standpipes. The building footprint is spread out, so I will need (8) standpipes to cover the hose lay inside the building (fully sprinklered). I'm assuming one 1,000 gpm pump will cover all the standpipe demand. To complicate matters, this is in a seismic area D classification, and with it being a high rise, I am required to have a secondary on-site water supply. The intent was to install an underground tank to supply the fire pump or pumps, if necessary. My thought was to supply water directly from the city main to the tank, and if there is ever a break in the city supply line, the pump would be served from water in the tank, which would have enough capacity to serve the facility for 30 minutes. Is 30 minutes the duration I need? What do you think about how I plan to serve the building? Would that meet the requirement for a secondary water supply? Do I consider the standpipe demand when sizing the underground tank, or just the most demanding area of my sprinklers? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is an alarm check valve required in a sprinkler system?
Is there an alternative to an alarm check valve? Are there any restrictions on where the alarm check valve is required to be (i.e., inside or outside of a fire pump room)? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 is pretty clear on the orientation of the eccentric reducer on the suction (upstream) side of a fire pump.
But the diagrams seem to suggest that the diagonal slope (not the flat side) of the eccentric reducer is always on the bottom. Is this true even when the supply is being fed from above? For instance, we often have a stub into a fire pump room from the floor, then a vertical backflow preventer, then the feed comes vertically-down and to the fire pump. Which way is correct for the eccentric reducer when the feed is from above? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a low-rise building with a manual wet standpipe and a sprinkler system. One combination riser is 6-inch and the other is 4-inch. Standpipes will be Class I.
The calculated sprinkler demand is 195 gpm (Light Hazard). My total manual wet standpipe system demand will be 750 gpm (500 gpm first riser + 250 gpm second riser). Does my fire pump need to accommodate the 750 gpm of the manual standpipe system, since they're interconnected? I know the fire department will handle the standpipe demand, but does the flow rating for the fire pump need to accommodate 750 gpm? I've searched but haven't found specific code references in NFPA 13 or 20 to address this sizing. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project where the owner just wants to manually turn a switch to transfer from main power to backup power for a fire pump instead of having an Automatic Transfer Switch.
Wouldn't this be considered manual activation under NFPA 20, and not be allowed? I would think this arrangement isn't allowed because that's not automatic transfer. Thanks in advance for your input. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have seen this method of arranging fire suppression components (see attached schematic) several times where I live. The attached is a partial re-creation of the fire water entry schematic for a high-rise building with a fire pump. The system has low and high pressure zones. The underground parking dry systems are served by the municipal water directly, and the standpipes and aboveground sprinklers are fed by the pump. Questions: 1. Can you have a FDC serving the low pressure zones as shown on the suction side of the pump per NFPA-14 6.4.3.1? 2. If not, how should the schematic be arranged instead? 3. What could happen if the Low Pressure FDC were pressurized as shown? This project was built under the 2013 editions of NFPA-13, 14, and 20. I am asking because I am beginning design of a sprinkler system for a 22 story high-rise. Thanks for your help. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is it code-mandated to have two control valves in the fire pump bypass piping?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe AHJ is requesting the design curve for the fire pump to be 5% lower than the pressure limiting driver (PLD) set pressure to account for the tolerance allowed NFPA 20-2019 Section 6.2.2.2 "When operating below the rated speed in a self-regulating mode, a self-regulating variable speed fire pump unit shall maintain the discharge pressure within 5 percent of the set pressure."
Is this an appropriate application for this requirement in NFPA 20? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have wrote up several pump sensing line locations where they tap into the system. I understand it that they need to be be install between the discharge check and discharge control valve.
A contractor keeps installing on the pump bypass and says it works fine. Is this compliant? Is there a downside to attaching to the bypass? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am a President of Board of a 4-story condo building. The building was built in 1982 and is concrete block.
We received permission from fire marshal several years ago to remove all our fire hoses. The fire department told us that if there was a fire they would not use them. They would hook up to the FDC in front of our building. My question is - what is the purpose of the building's fire pump, and can we petition to also have it removed? For multi family buildings, I am being told that for a 4-story building, normally the fire pumps are only 15HP because the standpipes are pressurized by the fire trucks.
My understanding of NFPA 20 is that it would still be required to have a correctly sized fire pump without considering the size of the pump on the local fire trucks. Is this an industry norm that is allowed by certain AHJ’s or is there code related to multi family that I am missing? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Would we still be required to conduct a forward flow test if we have a fire pump downstream and it's tested annually?
Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Had a review comment come back and needed to clarify. I have a 14-inch city main with an 8-inch tap to a backflow in a pit. It then runs to four hydrants, and then turns into the building supplying a fire pump. The flow test at the hydrant near the tap (#1 on image below) was 49 psi static, 47 psi residual at 920 gpm. The flow test at a hydrant nearest the building (#2 on image below) was 49 psi static, 39 psi residual at 750 gpm. The 95 psi @ 1,500 gpm pump in the building is running the underground dry. The plot curve shows 20 psi at 2,100 gpm, however the pump rep said he barely got 500 gpm at 9 pitot and had to shut it down as the gauges went below 20 psi and air was starting to come out of the 2-1/2" hose valves.
This is a mystery to us - we have five different flow tests all ranging from 750 gpm to 1,060 gpm at 40-32 psi residual. Why would the pump be pulling the underground so low? They checked all the valves and rebuilt the backflow in the pit. Water meter is good as well (per the utility department). Looking for suggestions. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can a floating dock standpipe with hose valves in the ocean be ran with PVC pipe?
NFPA 307 doesn’t go into detail about materials used but reverts back to NFPA 20, 22 and 24. This is in Florida. The AHJ wants it full of water so I have to issues, it’s too heavy to mount on the side of the dock, it’s not very big and it will be in the water or very close with high tide, so corrosion is inevitable. Is there anything stating Schedule 40 or 80 PVC is listed or acceptable for such use? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project with Miscellaneous Storage of Class I commodities up to 12'-0" and Group A plastics up to 5'-0".
The water supply is a tank fed from a well. Based on NFPA 13-2016 Table 13.2.1, I designed to Ordinary Hazard Group 2 with a 90 minute duration of available water. My original demand was 57 psi at 385 gpm. Our pump supplier provided a vertical in-line pump rated to 80 psi 400 gpm. The client is now unhappy about the volume of water being required so they are removing the Group A plastics from their building so we can calculate to OH I with the new demand being 41.5 psi at 304 gpm. We have already installed most of the system and the pump is ready to be delivered soon. Is it okay to have an oversized pump? Can it be limited to a smaller flow to accommodate the new demand? My worry is that it will flow at the rated capacity and if we are sizing our tanks 10,000 gallons less than originally planned we would run out of water. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a building with an Extra Hazard Group 1 in a fairly rural location. We have an Electric, Diesel and Jockey (electric) pump system.
We had our diesel go out, sent away for repairs. What are the requirements for just having just electric in place? My concern is is the fire department cuts power if they come on site for industrial fire, or lose power due to weather, then we would have no suppression in service. The fire department can provide 1,500 gpm at 100 psi from a Type 1 engine through the FDC, (so 750 gallons). We have a pond to draft from. What would be the considerations? Amount of water available? In the event of power loss, the size of the FDC versus the size of the riser (a 6-8" dry pipe valve)? What would realistic attack line demand be for a hydrant/hose line? Can you think of anything else I'm not thinking of? Thanks in advance for the help! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can a flow meter be installed in test header piping?
This is the first time I've ever seen this installation. Thanks. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is there a specific location requirement for a fire pump test header? NFPA 20 states that the header must be installed on the exterior wall, and outside the fire pump room. Does this mean that the test header cannot be installed in the fire pump room? Additionally, can the test header be directly connected to the pump discharge flange as shown in this photo? I have never seen this type of installation before. Thanks in advance.
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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