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Thread: High Rise Standpipe System FDC Pressure

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    Default High Rise Standpipe System FDC Pressure

    I am interested in how many story high rise building can you supply the required flow and psi for your attack lines with just the FDC. Worse case the building fire pump is out of service and you only have your engine pressure. NFPA 14 minimum is 500 gpm @ 100 psi at the class I or III standpipe connection.

    What would be your limitations, fire hose psi rating, engine psi max rating, FDC and piping rating, etc. I know every FD has different equipment and capabilities. I am thinking about 16 stories is about the limit based on math, am I correct?

    Thanks for your help.
    Last edited by InsuranceLCRep; 04-24-2014 at 07:24 PM.
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    Quote Originally Posted by InsuranceLCRep View Post
    I am interested in how many story high rise building can you supply the required flow and psi for your attack lines with just the FDC. Worse case the building fire pump is out of service and you only have your engine pressure. NFPA 14 minimum is 500 gpm @ 100 psi at the class I or III standpipe connection.

    What would be your limitations, fire hose psi rating, engine psi max rating, FDC and piping rating, etc. I know every FD has different equipment and capabilities. I am thinking about 16 stories is about the limit based on math, am I correct?

    Thanks for your help.
    So if you were trying to pump to 16 what would your psi be as you calculate it??

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    16 stories say each floor is 11'=176' x .433= 76.20 psi. Say 30% for friction loss, elbows, tees, etc. = 22.86 psi so you have 99 psi plus 100 psi at the top = 199 psi at the FDC . I guess the psi at pump discharge would depend on what size hose and how far away to the FDC. Now if the piping on the building and FDC is only rated for 175 psi, this will be a problem.

    What do you think?
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    Our rule of thumb is 100 PSI plus 5 PSI for each floor above grade. So we would pump at about 180 PSI to the Siamese to supply a 16th floor standpipe outlet. This is via 3 1/2 supply line and 2 1/2 handline with 1 1/8 tip. Goal is to get around 80 PSI at outlet with water flowing. Standard pumper can supply up to around 30th floor.

    One pumper required for each handline operating off standpipe.

    Standard pumpers and hose limited to 250 PSI. Also have high pressure pumpers that are limited to 600 PSI (with high pressure hose). Finally, there are 3 stage pumpers that will deliver 500 GPM up to 700 PSI.

    BC to supervise high pressure operation.

    No staging or resting in stairwells while high pressure pumping in effect.

    Supply lines must be tethered.

    Safety areas enforced.

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    Capt.

    Thanks I guess I am looking at it from a code design point of view with 100 psi at the outlet. The code says one thing but every FD as their own SOP on how they operate. Does anyone check what piping is rated for on prefire planning. NFPA says max psi on standpipe design is 350 psi, that 700 psi has me wondering. This is great info and something to think about, practical application vs. the building code.
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    We recently updated our SOP's after conferring with our building code officials and a group of building engineers. We now pump all FDC's at 180psi, which was the maximum pressure that the engineering and code officials felt safe with.

    Why so high? We're adjusting the outlet pressure with a gauged valve on the connection floor anyway, so we can pump it at a set pressure for all FDC's (our tallest building in the county currently is 11 floors, but a number of high rises [20+ stories] are in the works).
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    Quote Originally Posted by InsuranceLCRep View Post
    Capt.

    Thanks I guess I am looking at it from a code design point of view with 100 psi at the outlet. The code says one thing but every FD as their own SOP on how they operate. Does anyone check what piping is rated for on prefire planning. NFPA says max psi on standpipe design is 350 psi, that 700 psi has me wondering. This is great info and something to think about, practical application vs. the building code.
    I guess it depends where you are. NYC code is often different from NFPA by necessity. I don't know what the standard is for piping but I do know that it should stand up to whatever pressure is needed to get water to the top floor of the building, whether it's 10, 30 or 80 stories tall.

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    Quote Originally Posted by captnjak View Post
    I guess it depends where you are. NYC code is often different from NFPA by necessity. I don't know what the standard is for piping but I do know that it should stand up to whatever pressure is needed to get water to the top floor of the building, whether it's 10, 30 or 80 stories tall.
    NYC is totally out of the ordinary. They have manual fire pumps for the standpipe system in the basement operated by FDNY only in many high rise blds. However they just adopted the IBC a few years ago so things will change.

    You would be surprised on how many blds have FDC only rated for 175 psi. Then again how many have you heard blown up during a fire?

    Another question does your Dept. always connect and pump the FDC regardless if the building fire pump is operating?

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    InsuranceLCRep: Your assumption of 16 floors agrees with our std practice. Standpipe packs are 200 ft. of 1 3/4" lt wt. hose with a 50 psi automatic (I know I'm gonna get my Ba**s busted on here. Two lines are required , so the pack is equipped with a 2 1/2" x 1 1/2" gated wye with built in gauge. SOP for D/PO is 200 psi on a 3 x 2 1/2 supply to the siamese. Pressure stack up is as follows: Supply hose = 9 psi, Siamese & check = 10 psi: 5 psi per floor = 80 psi Wye & elbow = 10 psi: Fl on 200 ft of 1 3/4 = 56 psi nozzle press = 50 or 216 psi required by calculation. Our piping contractors assure us that, barring water hammer, standard sprinkler piping should handle 200 psi on a regular basis.

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    Quote Originally Posted by InsuranceLCRep View Post
    NYC is totally out of the ordinary. They have manual fire pumps for the standpipe system in the basement operated by FDNY only in many high rise blds. However they just adopted the IBC a few years ago so things will change.

    You would be surprised on how many blds have FDC only rated for 175 psi. Then again how many have you heard blown up during a fire?

    Another question does your Dept. always connect and pump the FDC regardless if the building fire pump is operating?
    It is the responsibility of the building engineer to operate the fire pumps, not the fire department.
    Fire pumps also have limitations in supplying water to upper floors. The primary water supply to the system is from gravity tanks on roofs of buildings. They do not allow for good pressure at the highest floor outlets due to lack of head pressure in piping. This is why we rely on FD pumpers. They are used regardless of fire pump operation.

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    Quote Originally Posted by kuh shise View Post
    InsuranceLCRep: Your assumption of 16 floors agrees with our std practice. Standpipe packs are 200 ft. of 1 3/4" lt wt. hose with a 50 psi automatic (I know I'm gonna get my Ba**s busted on here. Two lines are required , so the pack is equipped with a 2 1/2" x 1 1/2" gated wye with built in gauge. SOP for D/PO is 200 psi on a 3 x 2 1/2 supply to the siamese. Pressure stack up is as follows: Supply hose = 9 psi, Siamese & check = 10 psi: 5 psi per floor = 80 psi Wye & elbow = 10 psi: Fl on 200 ft of 1 3/4 = 56 psi nozzle press = 50 or 216 psi required by calculation. Our piping contractors assure us that, barring water hammer, standard sprinkler piping should handle 200 psi on a regular basis.
    kuh

    Thanks good to know I am in the ball park I was starting to wonder if my assumptions were wrong. I guess the answer is it depends on where you are at and what you bring to the fire and how many high rise blds you have. Sounds like Capt maybe with FDNY, hence they deal with this daily and have done so for 100 years.
    Great comments keep them coming....
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    Standpipes can make a huge difference with a fire attack when the building is equipped with them. Unfortunately everyone only thinks about using them for high rise buildings. Our tallest occupancy is 7 stories with many buildings below that height also having standpipes. We've also got them in a few factories. There you are pumping a horizontal distance instead of vertical but they can be just as effective.

    What bothers me most about standpipe systems is that all the theoretical calculations are usually correct at time of install. The water in our area is hard. Harder than my jaw struck the floor when I heard Kuh Shine uses combination nozzles on standpipes. (Why isn't there a sarcasm font already?) As the mineral deposits build over time they basically negate all the calculations due to the increased friction loss created by irregular surface as well as decrease in the size of the pipe. Using a gauge at the standpipe connection will allow you to monitor what pressure is available (both static and residual) and the pump operator can increase to the FDC as needed but if a system can only handle 200 psi there will be a time you cannot meet the interior crews demands for water which can be catastrophic. Getting water into the FDC isn't the problem in my mind, it's if the standpipe system can get it to the connection.

    InsuranceLCRep, I've never heard of 350 psi to a standpipe system but I am also not that well versed with them. I know that pressures changed when the standard changed, in the 90's? Our department's SOP is to pump 200 psi.

    While you're having a code/standard debate, how about requiring the FDC to have signage for the maximum intake pressure above it? I know it could be local code but it's not ours. Just a thought.

    Good discussion.

    Walt
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    Walt,

    NFPA 25, 2011 Ed requires the following.
    6.3.1 Flow Tests.
    6.3.1.1* A flow test shall be conducted every 5 years at the hydraulically most remote hose connections of each zone of an automatic standpipe system to verify the water supply still provides the design pressure at the required flow.
    6.3.1.3 All systems shall be flow tested and pressure tested at the requirements for the design criteria in effect at the time of the installation.

    If your local AHJ has adopted NFPA 25 the problem with hard water and reduced flow should be corrected by the building owner.

    Good point about standpipe system not only being in high-rise buildings. They also can be found in manufacturing occupancies including warehousing and any other hazardous locations. When you have a large warehouse the inside hose stations are needed to do the final extinguishment of the fire. I find many times these connections are buried in stock and are not maintained.
    Last edited by InsuranceLCRep; 05-08-2014 at 05:07 AM.
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    Thanks for the info.
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    Quote Originally Posted by FFWALT View Post
    Standpipes can make a huge difference with a fire attack when the building is equipped with them. Unfortunately everyone only thinks about using them for high rise buildings. Our tallest occupancy is 7 stories with many buildings below that height also having standpipes. We've also got them in a few factories. There you are pumping a horizontal distance instead of vertical but they can be just as effective.

    What bothers me most about standpipe systems is that all the theoretical calculations are usually correct at time of install. The water in our area is hard. Harder than my jaw struck the floor when I heard Kuh Shine uses combination nozzles on standpipes. (Why isn't there a sarcasm font already?) As the mineral deposits build over time they basically negate all the calculations due to the increased friction loss created by irregular surface as well as decrease in the size of the pipe. Using a gauge at the standpipe connection will allow you to monitor what pressure is available (both static and residual) and the pump operator can increase to the FDC as needed but if a system can only handle 200 psi there will be a time you cannot meet the interior crews demands for water which can be catastrophic. Getting water into the FDC isn't the problem in my mind, it's if the standpipe system can get it to the connection.

    InsuranceLCRep, I've never heard of 350 psi to a standpipe system but I am also not that well versed with them. I know that pressures changed when the standard changed, in the 90's? Our department's SOP is to pump 200 psi.

    While you're having a code/standard debate, how about requiring the FDC to have signage for the maximum intake pressure above it? I know it could be local code but it's not ours. Just a thought.

    Good discussion.

    Walt
    I wouldn't think you would get much of a buildup from hard water in a standpipe or sprinkler system. You don't have water circulating in them, the water that they have in them is static and stays in them generally, unlike the pipes used for water consumption where new water and minerals are continually introduced.

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    Quote Originally Posted by johnsb View Post
    I wouldn't think you would get much of a buildup from hard water in a standpipe or sprinkler system. You don't have water circulating in them, the water that they have in them is static and stays in them generally, unlike the pipes used for water consumption where new water and minerals are continually introduced.
    Actually the build of stuff in the pipe is a problem, so much so NFPA 25 requires an internal inspection of the pipe every 5 years, see below from the 2011 Ed

    14.2 Internal Inspection of Piping.
    14.2.1 Except as discussed in 14.2.1.1 and 14.2.1.4 an inspection of piping and branch line conditions shall be conducted every 5 years by opening a flushing connection at the end of one main and by removing a sprinkler toward the end of one branch line for the purpose of inspecting for the presence of foreign organic and inorganic material.
    14.2.1.1 Alternative nondestructive examination methods shall be permitted.
    14.2.1.2 Tubercules or slime, if found, shall be tested for in- dications of microbiologically influenced corrosion (MIC).
    14.2.1.3* If the presence of sufficient foreign organic or inorganic material is found to obstruct pipe or sprinklers, an obstruction investigation shall be conducted as described in Section 14.3.
    14.2.1.4 Non-metallic pipe shall not be required to be inspected internally.
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    Quote Originally Posted by johnsb View Post
    I wouldn't think you would get much of a buildup from hard water in a standpipe or sprinkler system. You don't have water circulating in them, the water that they have in them is static and stays in them generally, unlike the pipes used for water consumption where new water and minerals are continually introduced.
    Recent fire by me where several sprinkler heads failed to operate. Totally clogged. Clearly they fell through the cracks of the 5 year test. They don't have to test every branch for build-up. Same with flow test if I remember correctly.

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    Quote Originally Posted by captnjak View Post
    Recent fire by me where several sprinkler heads failed to operate. Totally clogged. Clearly they fell through the cracks of the 5 year test. They don't have to test every branch for build-up. Same with flow test if I remember correctly.
    Cvpc pipe??

    Recalled heads??

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    Quote Originally Posted by captnjak View Post
    Recent fire by me where several sprinkler heads failed to operate. Totally clogged. Clearly they fell through the cracks of the 5 year test. They don't have to test every branch for build-up. Same with flow test if I remember correctly.
    Wow if you have more details as to the type of system the sprinklers were connected to that would be helpful. NFPA 25 does not require every head to be inspected, just a few on a system. A system can be as much as 52,000 sq.ft. As fire49 indicates we know what sprinklers that have a problem not operating during a fire. I hope your department let someone know about the problem.
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    We have an entire unit of civilian inspectors that handle fire suppression systems. It was handed off to them. They took sections of the system for analyses. Not sure of the outcome. I do know the inspector stated the system did pass most recent 5 year test. He also stated heads were probably about 50 years old. System was all metal piping. Many heads did operate and fire was confined to one area of cellar. Five story former school with several branches per floor.

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    Quote Originally Posted by captnjak View Post
    We have an entire unit of civilian inspectors that handle fire suppression systems. It was handed off to them. They took sections of the system for analyses. Not sure of the outcome. I do know the inspector stated the system did pass most recent 5 year test. He also stated heads were probably about 50 years old. System was all metal piping. Many heads did operate and fire was confined to one area of cellar. Five story former school with several branches per floor.
    Sprinklers are only good for 50 years as per NFPA 25, they need to be tested or replaced, so perhaps they were no good. Thanks for providing more details, very helpful.
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