A FORUM FOR FIRE PROTECTION QUESTIONS & PE EXAM PROBLEMS | SUBSCRIBE NOW
|
I've seen floor control assemblies (isolation valve, sometimes a check valve, waterflow switch, test & drain) in many different configurations as far as spacing of each of the components. I also understand that several manufacturers make an "all in one" valve assembly that can have all of these components.
Is there any benefit to the operation of the waterflow switch by spacing out these components? I'm wondering if a steady stream from the test and drain that is further from the switch allows the waterflow switch to operate more consistently? Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
2 Comments
A building addition is to connect two existing buildings of different construction types. Which of the following construction type arrangements is always permissible?
a. Provide the least fire-resistive construction type of the connected portions with no fire barrier separation b. Provide 1-hour vertically aligned fire barrier wall is installed between them to create separate buildings c. Provide any construction type for the connection portion with 2-hour fire barrier between buildings d. none of the above Is there a reason why OS&Y would be better on backflow preventers for fire suppression systems over butterfly valves?
One application where we often must use the OS&Y is when the backflow serves a fire pump and we don't want to distort the flow and cause cavitation at the pump - but otherwise the butterfly valves are a major space saver. Just curious if others feel differently or if I'm missing a major benefit to the OS&Y type. Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe A hospital's patient tower has an an exit access corridor with 1/2 hour partition fire resistance rating on the first level. If the interior architect would like to provide side transoms (narrow windows) along the side of the doors that lead to the exit access corridor, what fire resistance rating must the transoms have? a. 1/3 hour b. 1/2 hour c. 3/4 hour d. 1-hour Solution | Posted 06/8/19
 The Leaderboard lists the total scores for the most recent weekly exams for PE Prep Series participants. See the entire scoreboard here.  Want to join in? It's not too late - the PE Prep Series 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
Do you know what the protocol is if I am the engineer of record for an ongoing project when I change employers? Am I obligated to continue to provide engineering services?
Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe 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 06/17/19
The 2015 Edition of the International Fire Code added some clarity for water supply for buildings with automatic sprinkler systems.
The Annex B material (not enforceable unless adopted) states: B105.3 Water supply for buildings equipped with an automatic sprinkler system. For buildings equipped with an approved automatic sprinkler system, the water supply shall be capable of providing the greater of: 1. The automatic sprinkler system demand, including hose stream allowance. 2. The required fire-flow. In the past I've heard several people say that only inside hose allowances are included when determining the total volume required (which sizes the water storage tank). Would you interpret this section of IFC to include both the inside and outside hose allowance? Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe The pressure gradient that causes a liquid to move through the intake line to the pump impeller is: a. Total static head b. Net positive suction head c. Net discharge head d. Rated head Solution | Posted 06/14/19
If you'll be in San Antonio next week, be sure to stop by and say hi at booth 460. Would be happy to meet you in person!  For standpipe hose connections within stairwells, does ADA (Americans with Disabilities Act) restrictions apply to the dimensions of hose valves coming off pipe?
ADA - 2010 Standard 307.2 Protrusion Limits. Objects with leading edges more than 27 inches (685 mm) and not more than 80 inches (2030 mm) above the finish floor or ground shall protrude 4 inches (100 mm) maximum horizontally into the circulation path. 307.3 Post-Mounted Objects. Free-standing objects mounted on posts or pylons shall overhang circulation paths 12 inches (305 mm) maximum when located 27 inches (685 mm) minimum and 80 inches (2030 mm) maximum above the finish floor or ground. In particular, I'm wondering if the 4" protrusion limit applies to standpipe hose connections off of a vertical standpipe, and if it does, if it only applies if the standpipe hose connection is pointed into the path of egress? I would imagine there's some life safety experts that could explain this better than I surely am. Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe A new Type II (000) construction facility without exposure protection is being designed to be built on an industrial campus. If Class II liquids are planned to be handled and dispensed regularly within the facility, what minimum distance from an adjacent, build-able property must the building allow? a. 5 feet b. 10 feet c. 25 feet d. 50 feet Solution | Posted 06/13/19
Where concrete anchors are used for seismic bracing, they must be "prequalified". Is this just an additional listing that is required to meet ACI 355.2?
Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe Halocarbon clean agents are effective fire extinguishing products due to what principal(s): i. oxygen dilution ii. heat extraction iii. chemical combustion interruption a. ii only b. i and ii only c. ii and iii only d. i, ii, and iii Solution | Posted 06/12/19
 The Leaderboard lists the total scores for the most recent weekly exams for PE Prep Series participants. See the entire scoreboard here.  Want to join in? It's not too late - the PE Prep Series 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
In general, when designing fire sprinkler systems with a fire pump, is your philosophy to only provide the minimum fire pump size that is needed to support your system, or do you often increase the fire pump size to decrease pipe sizes on the system?
How much are you typically willing to increase a fire pump size in order to benefit the pipe sizes throughout your project? When I first learned about how to size a fire pump, I was told that if your system gets over 100 psi then you might as well size the pump to get as close to 170-175 psi on the system as possible - the reason being that the cost to upsize a fire pump is less than the savings associated with smaller mains and branch pipe. I'm not sure that there's a hard-and-fast rule of thumb, but I'm just interested if other people use the same strategy or if it's entirely dependent on the type of job and size of the job. Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe What is the greatest allowed spacing among all pipe sizes between hangers for CPVC pipe in fire sprinkler systems? a. 6'-0" b. 9'-0" c. 10'-0" d. 12'-0" Solution | Posted 06/11/19
What is the ideal approach for fire sprinkler pipe to enter a building?
I find many engineer details show either an in-building riser (by Ames) or a ductile iron pipe with restrained pipe and fittings come under the building foundation and up into the building. While this approach is acceptable, if we have the ability to coordinate with the structural foundation during design, would it not be better to drop the footing so that the fire sprinkler pipe can be sleeved through the vertical portion of the foundation wall? I would think that running through the foundation wall would put far less pressure onto the pipe and joints itself. I understand when most installation/design work is completed is usually well after structural design, but when we do design upfront wouldn't this be the best-case scenario? Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe A stair is 59 inches wide, with a handrail on one side with a centerline of 1.5 inches from the edge of the stair. The other side of the stair is a wall. For the purposes of calculating a specific flow, what is the effective width of the stair? a. 47 in. b. 48 in. c. 53 in. d. 59 in. Solution | Posted 06/10/19
On recent inspections I've seen many installations where an automatic ball drip is not provided anywhere on the pipe connection between the fire department connection and the check valve that serves the fire department connection. Is there an exception I'm missing or isn't that automatic ball drip always required?
Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe Inergen (IG-541) is being used for protection of several rooms which contain highly valuable historic documents. If the fire type is considered Class A and the design concentration of Inergen is provided, determine the clean agent-air mixture density. a. 1.15 kg/cu. m b. 1.25 kg/cu. m c. 1.28 kg/cu. m d. 1.44 kg/cu. m Solution | Posted 06/07/19
Have a unique scenario I'd be interested in other's take on. Eight-story building with automatic standpipes and a fully-sprinklered building. There's multiple scenarios where the building is close enough to an adjacent building that the exterior wall needed to be rated. In order to keep the fire resistance rating Tyco window sprinklers were installed in conjunction with glass to provide up to a 2-hour fire resistance rating.
The issue is that the sprinkler system experiences a working pressure of up to 220-230 psi, while the window sprinklers are only available as rated up to 175 psi. We've proposed adding pressure reducing valve to the seven floors affected by this situation, but that introduces its own issues aside from cost. We've also suggested replacing the glass with a rated glass. Are there other alternatives we haven't explored here? Would be interested in others' opinions. Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe 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 06/06/19
Without the context of a specific project or problem, when would you recommend creating a separate, detached fire pump house versus a fire pump room inside a building?
Is is purely a risk perspective? Do you recommend fire pump houses only when a pump is feeding multiple buildings, or a campus? I've only had a few projects that used a fire pump house, and it has generally been in retrofit situations or when the pump is next to a water storage tank. In either case the pump house overall cost more than it would have should the fire pump room been within the building (even despite the simple construction of the pump house). Just curious on getting another perspective. Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe A stair is being designed as pressurized as part of a smoke control plan. A single door gap below a 4 foot wide door has a 0.35 inch tall door gap where the pressure differential between the two sides of the door are 0.1 in. w.g.. Assuming a flow coefficient of 0.7 and normal atmospheric conditions, what is the volumetric flow rate of air through the gap? a. 33 cfm b. 73 cfm c. 104 cfm d. 148 cfm Solution | Posted 06/05/19
|
Free SignupSubscribe and learn something new each day:
CommunityThank You to Our Top May 2019 Contributors!
Your PostThe ToolkitSprinkler Designer or Engineer?
Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more: 
Filters
All
Archives
June 2019
Daily
Daily discussion questions are open-ended questions posed by members for the benefit of sharing expertise and learning from other perspectives. Join as a member here.
Exam Prep
2019 PE Prep Guide
(Available Now!) 
PE Prep Series
(Available Now!) Current Leaderboard
PE Problems
Visit July-October for daily Fire Protection PE Exam sample questions.
Solutions are posted the day after posting. Comment with your solutions, questions or clarifications. Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves. |
RSS Feed
