Have a project that requires the sprinkler system to be zoned by the areas with active smoke control. Each floor of the highrise is approximately 12,000 sqft is to be divided into two zones. I intend to have multiple floor control risers (valve, check valve, flow switch, pressure gauge, inspector's test & drain) for each smoke control zone. Is there any less costly way of accomplishing this?

It has been suggested that multiple flow switches can be placed on the same system with different retard settings so that the fire alarm system can identify where the water is flowing, but I don't have experience with this option.

Posted anonymously by a member for discussion. Discuss this | Subscribe.

It's close to the end of the year and for some states that means making sure continuing education credits are all wrapped up. Where do you find good continuing education for fire protection?

Posted anonymously by a member for discussion. Discuss this | Subscribe.

I have a question regarding performing or checking hydraulic calcs for a pressure tank supplied system in a retrofit application.

As an example, suppose our system is located 5 floors below the existing pressure tank for a high rise building in New York City (NYC). The tank was designed and installed under prior codes and utilized the pipe schedule methods. We may have 2 tanks connected that are 9,000 total gallons capacity each with 1/3 air and 2/3 water pressurized at 75 psi (the initial pressure) at the tank.

Our connection to the sprinkler riser being 5 floors down now has 75 psi plus the pressure gained by gravity (5 psi per floor typical NYC arrangement) equaling 100 psi static available.

The jurisdiction now requires all systems to be hydraulically calculated. The calculation are done to the point of connection to the riser and not all the way back to the water source (NYC quirk) and no hose demand.

The contractor provides a calculation stating that the system demand is below the 100 psi (95 psi residual) and less than 400 gpm (light hazard occupancy 30 minute supply), and claims it works. We’ve argued that as the tank drains, the air-to-water ratio changes, therefore the pressure available at the end of the 30 minutes is not the same as initial tank pressure.

Using the formula given in the Annex of NFPA 13, we can solve for what a system demand should be given the existing initial conditions of the tank plus the pressure gained by gravity and say that as long as the calculated system is less than that pressure, the system is acceptable. But is that a correct assumption?

I want to give them all the correct procedure, methodology and theories behind this subject.

Posted anonymously by a member for discussion. Discuss this | Subscribe.

This post-exam survey is the single-most helpful way we gather feedback from the exam. The 2017 survey results helped us refine topics, add more content, improve the quality of questions, and improve the 2018 Prep Guide. We are constantly trying to improve our questions, prep guide, and other online material to help you pass.

​If you have just taken the PE Exam, please take just a few minutes and give us your feedback through this quick survey. If it doesn't appear below, you can view the complete survey here.

​Thank you in advance for your feedback!

A project that has evidence storage will have a new fire sprinkler system. The storage is anticipated to be solid back-to-back shelves no more than about 8 feet in height, but will hold crime evidence which could and will likely include firearms. What sprinkler design density is required for this area?

Posted anonymously by a member for discussion. Discuss this | Subscribe.

A retrofit project has very low floor-to-floor heights where we need to install floor control assemblies within the stairwells. Is there a minimum "head height" for the pipe that it needs to be installed above the floor if the pipe isn't against a wall?

Posted anonymously by a member for discussion. Discuss this | Subscribe.

When are pressure relief valves required for fire pumps, and what is their intended purpose? There's a wide variety of pump arrangements and many don't include pressure relief valves.

​Posted anonymously by a member for discussion. Discuss this here.

We're in the process of reviewing our specifications against industry markers and I'm interested in comparing major differences in owner-driven specifications (not NFPA, FM, XL GAPS, or other insurance standards). What clients do others work with that they find represent good practice for the industry?

​Posted anonymously by a member for discussion. Discuss this here.

Have a project which requires very tight coordination between sprinkler and ductwork. The ductwork will be lined with insulation which could come in contact with the black steel fire sprinkler pipe. Is there a minimum clearance required that wouldn't permit this contact by code?

​Posted anonymously by a member for discussion. Discuss this here.

A big pat on the back for all of the 2018 Weekly Exam participants - there are a lot of hours and a lot of work on preparing, taking, and analyzing the 200+ questions that have come through over the last five months. 

​The Leaderboard lists the total scores for the last three weeks for Weekly Exam participants
​

This year we're happy to award new glass plaques for the Top 3 in the season standings, which are:
Another Bad Summer, Princess and the PE, and JT. Congrats!

The activation time (in seconds) of a standard response (RTI of 85 m^1/2s^1/2), Ordinary Temperature (65 deg C) heat detector within a room that has an initial temperature of 22 deg C and exposed to a ceiling plume at 78 deg C traveling at 2.3 m/s is most nearly?
     a. 10 s
     b. 36 s
     c. 54 s
     d. 82 s

Solution | Posted 10/24/18

A 500 sqft rated liquid storage room is to be created within a fully-sprinklered 200,000 sqft warehouse. How many 55 gallon drums of Class IIIB liquid (flashpoint above 200 deg F) can be stored within this room?
     a. 18 containers
     b. 36 containers
     c. 87 containers
     d. 90 containers

Solution | Posted 10/23/18

2015 NFPA 101:  A college classroom building is a Business occupancy.  For occupant load relative to the classrooms, do you use the Educational amount of 20 SF net or do you use the Business square-footage amount? In the past, we’ve used the Education load because it seemed logical;  but is this correct?

​Posted anonymously by a member for discussion. Discuss this here.

​A 4-inch schedule 40 main is routed parallel in-between two beams and requires a trapeze hanger. The main is 2 ft. from one beam and 8.5 ft from the other for a total span of 10.5 ft. What is the smallest schedule 10 pipe capable of supporting this main as a trapeze hanger?
     a. 2 inch
     b. 2-1/2 inch
     c. 3 inch
     d. 3-1/2 inch

Solution | Posted 10/22/18

​A secondary containment tank is constructed to handle overflow from fuel in a storage area. If a 540 kW/m fire occurs from the fuel in the trench, determine most nearly the flame height.
     a. 1.1 m
     b. 2.3 m
     c. 4.6 m
     d. 11 m

Solution | Posted 10/18/18

​An elementary school must perform a fire drill at least:
     a. Once per month
     b. Once every other month
     c. Once per semester (twice each year)
     d. Once per year

Solution | Posted 10/17/18

Which of the following plastics has the lowest decomposition temperature?
     a. PBT (polybutylene terephthalate)
     b. PET (polyethylene terephthalate)
     c. PMMA (polymethyl methacrylate)
     d. PTFE (polytetrafluoro ethylene)

Solution | Posted 10/16/18

​The Leaderboard lists the total scores for the last three weeks for Weekly Exam participants
​

Want to join in? It's not too late - the Weekly Exam is the ultimate PE Prep tool. It's a series of 1-hour, 10-question simulated PE Exams offered weekly with solutions immediately following each exam. Learn more here. ​​​​Every week of the series is retroactive so you can still test yourself with past week exams

White Oak wood having a density of 450, moisture-content of 25% is exposed to a standard fire (ASTM E119) test for 2 hours. What is the expected char depth most nearly?
     a. 1 mm
     b. 64 mm
     c. 78 mm
     d. 224 mm

Solution | Posted 10/15/18

​Fire sprinkler system design has been based upon all of the following except:
     a. Empirical flow and pressure loss calculations
     b. Application of experienced judgement and reasoning
     c. Mathematical suppression modeling
     d. Evolutionary changes based on fire loss

Solution | Posted 10/12/18

​A new-construction high-rise is being installed. Where a vertical trash chute has openings into a room on each floor, which of the following is not required?
     a. The room must not be greater than 400 square feet (37 square meters)
     b. The chute can be no greater than 24 square feet (2.2 square meters)
     c. The room may only be used for storage
     d. The room must have automatic sprinklers

Solution | Posted 10/11/18

A project site is connected to a water tank through an equivalent 650 feet of 6-inch schedule 10 pipe (c-factor of 140). If the water tank is 165 feet above the project site, the fire flow available at the project site is most nearly:
     a. 1,300 gpm
     b. 2,100 gpm
     c. 2,400 gpm
     d. 8,700 gpm

Solution | Posted 10/10/18

Where can I find presentations or references on the differences between NFPA 13-2016 and 2019 editions?

​Posted anonymously by a member for discussion. Discuss this here.

​A fire department connection may be installed by any of the following arrangments except:
     a. Between the supply control valve and the system control valves for multiple sprinkler systems
     b. Attached to underground system piping, between the supply control valve (at the main tap) and the system control valves (inside the building)
     c. Attached to main pipe on a system (on the system side of the system control valve) for a single wet system
     d. Attached to the main service between the utility tap and the entry into a fire pump room

Solution | Posted 10/09/18