Fire Fighting Pipe Network Sizing

Thanks for the idea, but the question remains unanswered. Answers are invited from someone with more patience, humility and understanding.

For the sake of completeness about the scenario, I must also note that the network to be calculated is loop type with 3000 sprinklers

So you do the calculations and you find that one of the pipe diameters comes out at 4.63in. What are you going to do now? Let the factory burn down while you spend a load of money getting pipe and fittings of that diameter specially made? Don't be silly.

When the pipe sizes are calculated by the software, I would indeed have to make the changes to resolve the issues of non existing pipe sizes as pointed out.

However, the question has still not been answered namely that in the available software, does one need to put the pipe sizes from the Pipe Schedule System. If yes, then what is the point of the software. Thanks.

Only people with patience need respond and they do not have to be Gurus.

"However, the question has still not been answered namely that in the available software, does one need to put the pipe sizes from the Pipe Schedule System. If yes, then what is the point of the software. Thanks."

The point is that the software determines the minimum pipe sizes to build the system.

You then go in and adjust the pipes at the extremities up to the size of pipe available.

Then the software uses that info to recalculate the minimum pipe sizes needed to feed that setup.

Rinse and repeat until you've set the pipe sizes all the way back to the water main, or the software tells you that you need a bigger water main, which means you need to either split the system into multiple zones that are fed from different mains pipes, or set up a pressure booster system that will not stop working if power is lost to the pumps, generally by using a water tower to 'store' the pressure.

If you want the software to do your entire job for you, then your supervisor ends up asking, "Why do we need YOU here, if the computer is doing all the work?"

The point of the software is to enable the network calculation to be done speedily and effectively utilising the pipes that are available, which it needs to know about in case the required size cannot be found in the schedule. The calculations are iterative, time-consuming and tedious if done by hand. A machine can make the job quicker and effortless.

Got it?

So can this forum, if manipulated as the OP has attempted to do, more.than once.

"So can this forum, if manipulated as the OP has attempted to do, more.than once."

With the side effect from the OP and his ilk acting as such that the regular posters become jaded and cynical, and newcomers can expect as much, if not more, sarcastic abuse from this site as from a visit to Mistress Helga's Dungeon of Pain and Discipline⁽¹⁾.

Notes:

1. If there is an actual dominatrix using that business name for her endevores, please do NOT tell me, I don't wanna know.
   

The term "fire fighting" has no ambiguity.

The system is intended to fight fires. Fires can kill people!

Only qualified people should be allowed to design LIFE SAVING "fire fighting" systems.

YOU ARE NOT QUALIFIED.

I don't believe anyone here will help you.

I will not!!

I agree with Tornado. If you are incapable of performing this task you should look for a different job, before something you do kills someone.

You have made some very sensible comments, but they are based on a misunderstanding, for which I do not blame you.

The misunderstanding is that there is no claim that I am the designer. I am just looking for the software but so far have not come across one that does not rely on the Pipe Schedule System.

By the way, this clarification is not given to extract an answer from you, because you are perhaps another Guru. I need answers from someone who is lesser than Gurus

Your first statement was "I would like to calculate hydraulically the pipe diameters of the firefighting network for light, ordinary and extra hazard classifications of the wet pipe sprinkler system as per NFPA."

To me, that sound like YOU "would like to calculate hydraulically the pipe diameters of the firefighting network."

The term "guru" does not carry any connotation of intelligence/knowledge/education or even experience, but rather just longevity on CR4.

I suggest you consult a qualified member of the staff of which you are a member.

Don't play with fire, you'll get burned.

Dear lyin,

I just want to be a positive thinker. If you don't want to help him/her, do not insult him/her.

You can imagine if he/she is you, as a young beginner employee has a duty from his boss as a "first trial" without any guidance from the boss. Trying many sources including this community to solve his/her problem.

Every professional also started from the beginner and now you are in the stable position.

Be possitive.

Arijanto,

I am positive. Positive that solidspaces has been a member since 12/08/2011.

If you go here: Posts and comments by solidspaces you can see how he has used the forum.

I assume that he must have had SOME education/experience that helped him get his present position. Maybe not.

I am also positive that since that time he has not demonstrated any advancement in his abilities.

Please feel free to help him in his quest to have strangers do his work for him, instead of trying to give me a lesson in good behavior.

This is an engineering forum, not charm school.

Dear Arijanto,

Thanks for your arbitration. It is nice to find a positive thinker who is trying to instill sobriety.

Good Luck and thanks for your 5 star input.

OP is not a new engineer. They have been coming here for 4 years.

Your preaching to me helps the OP in what way?

Did you provide them with even a tiny shread of help? No! You just took the side of someone who has repeatedly asked the forum to do their work for them.

Good luck.

The point of the software is to prove to the AHJ, the Insurance company, and the facility owner, that the system has been designed such that the most remote section of the sprinkler system has adequate water supply.

Designing the sprinkler system and plugging this information into the software must be left to those who are qualified.

Finally, there is an answer from WJMFIRE that comes a bit close to the inference that I drew from the software companies, namely that, the hydraulically calculated sprinkler system is merely calculating the pump capacity (GPM & Head) to match the design density of the remotest (highest pressure drop) section. If so, this is no different than what is done when designing the system as per the pipe schedule system of NFPA as detailed in NFPA Chapter 13.

Wow, what a fuss and waste of time to give a simple feedback! When I was at school, I saw the foreign students being advised to take a course in English. Now I feel, that the schools should advise the locals to take a course in manners.

Thanks WJMFIRE.

I found our Ethics University paper to be most helpful.

You do realise the comments here and in other threads (be they somewhat a little to quite over the top for my tastes) are based around the premise that you appear to be trying to do something dangerous you are not qualified to do, and wanting others here to help you do it.

Your previous thread certainly didn't help your case either or show this not to be the case.

http://cr4.globalspec.com/thread/98999

Now we get dangerous looking questions like this all the time on CR4, the responses to your questions and comments certainly appear to be over the top however.

I just checked the threads by the OP. I remember the one that was posted a while ago http://cr4.globalspec.com/thread/98900 I didn't even chime in on that one because it was so ridiculous a question!

UGH!!!

I have a few questions for you.

• Are you actually designing a fire sprinkler system?
• Or is this a brain exercise?

There are quite a few things that are needed to assist you.

1. A fire sprinkler system will be designed and installed using the standard piping sizes available.
2. Plus the style and flow of each head must be calculated first.
3. I doubt highly that a designer will spec out an odd size pipe just because it calculates out at that I.D.. They will use the next larger size pipe and move on.
4. I've never designed a fire sprinkler system but I have seen many installed, modified and maintained. BY PROFESSIONALS!
5. I have never heard the installers mention anything regarding a "custom I.D." piping!
6. To tell you the truth I'm having difficulty in actually understand exactly WHAT you are trying to do?
7. Also, any software is going to reference the standard pipe sizes because not one company will fabricate a custom piping design unless you bear the entire cost of the pipe fabrication and all of the related fittings. That is just moronic!
8. Software is a tool. As has been said here before GIGO. (Garbage In Garbage Out) The software is only as good as the people that wrote the code! The software will calc. out the specific hydraulic flow needed and then spec. out the required STANDARD pipe size!

I would like to calculate hydraulically the pipe diameters of the firefighting network for light, ordinary and extra hazard classifications of the wet pipe sprinkler system as per NFPA.

By all means.... go ahead but you are wasting your time and the time of everyone here if this is just a "brain game" for you.

Read up on the specific calculations needed and grab your calculator and calculate away!

I will accept the blame of improper wording that has led you to believe that by Pipe Schedule System, I mean irregular pipe sizes that are not available in the market.

The Pipe Schedule System of NFPA stipulates the minimum pipe sizes according to the number of sprinklers.

I do understand that say, the program outputs a pipe size of 1.111 inches, there is nothing like that in the market. So it will have to be rounded to a pipe that is 1 - 1/4 inches in diameter.

Due to not having used the software for fire fighting networks, I am trying to get the information figure out whether the input of diameters need to be as per the Pipe Schedule table that is in Chapter 13 of NFPA or one could input other pipe sizes, or even enter ZERO as the pipe diameter, to obtain the diameter that the software will calculate.

I am trying to buy the software for our company library.

What is the name of your firm?

Better than that, what are the names of the software packages that you have researched thoroughly? Mechanical design is outside my area of expertise, but software is not; I can name at least three packages that do what you want the way you want to do it.

Here's a hint; none of them output random pipe diameters as you purport, all of them conform to the methods presented in NFPA 13 using their calculations, charts, graphs, and standard pipe size tables. A package that doesn't programmatically duplicate the results obtained by hand calculations will never be accepted by those who follow such codes. Nice try, but no free software here.

I understand now.

That is probably a very specialized piece of software and may even be proprietary to the fire sprinkler industry which means get ready to either get turned down flat or add several zero's to that check you're going to have to write.

I don't ever recall seeing software like what you're thinking of. If it's out there, just keep searching the internet with multiple search terms.

Good luck!

Bryan

Perhaps I was too abrupt in my earlier messages. There are two uses of the term "pipe schedule" in this application, and it didn't seem as if you really knew about either. That may just be an unlucky choice of wording, but it came across as much too naïve.

1. One meaning of "pipe schedule" is a standard set of wall thicknesses for various diameters of pipe. There used to be Schedules 5, 10, 20, 40, 80, and 160; and maybe 30, 60, and 120. (Along with verbal designations such as standard, extra strong, and double extra strong.)

2. Another meaning is a table of equipment sizes and details that tells what size and type goes in each position of an installation. There may be schedules for doors, windows, electrical panels, kitchen cabinets, appliances, pipe, and others.

This thread contains a number of misconceptions about pipe flow and pressure drop. It would take a considerable treatise to sort them all out.

Said treatise would be wasted on the OP.

If history is any indication.

Be positive.

Buy the one that says its to calculate sprinkler system piping and be done!

How hard can it be?

You do not understand any of it as presented in all your posts. So listen to the software provider and get what you want for your library!

SPECIAL THANKS TO OLDSALT FOR AN EXHAUSTIVE RESPONSE

Let me "Tornado" you: STOP SHOUTING!

Dear Respondents

I would like to thank all the respondents and particularly those who have taken the time to give relatively more detailed feedback compared to the others, but I thank all of you for the info and intentions.I also appreciate the criticisms raised about my earlier posts.

Meanwhile a state of the art software has been acquired and it is working fine, therefore this thread is closed as far as I am concerned.

Thanks

The reason for all software requiring entry of pipe diameters from the NFPA pipe schedule is because the sizes are determined by applicable local and governmental code regulations and it is the design engineer's responsibility to determine which of the code regulations applicable for the installation site.

The applicable controlling regulations are dependent on the application requirements.

A few considerations are:

Hazardous classification?

Class 1 Division 1? Class 1 Division 2? Class 2 Division 1? Class 2 Division 2?

Type of Manufacturing Process and Equipment Used.

Type of Building Construction and Composition.

Number of Sprinkler Heads.

Type of Sprinkler Heads.

Size of Sprinkler Heads.

Length of Main and Lateral Pipe Runs.

Installed Height Head Pressure Requirements.

Classification for Source of Water.

Ambient Temperature and Insulation Requirements

It has been a while since my direct involvement with a wet fire protection system design so I am sure there are some considerations I have missed however this should give you some understanding of why pipe diameters are specified by the NFPA.

Allow me to provide an answer with as little sarcasm as possible, (I'm struggling here, my snark gland wants to overflow):

1. You want to design a sprinkler system for three different classifications of wet pipe sprinkler systems. (This sounds less like 'I have a specific project' and more 'I want to be taught for free.')
2. The purpose of a sprinkler system is to cover the area with a certain minimum GPM of water to suppress/extinguish fires.
3. To determine the GPM a pipe can deliver, you need to know the diameter of the pipe AND the pressure of the water supply.
4. Pressure is normally a fixed minimum value from the water mains, unless the demand GPM on the water main exceeds the supply GPM, the mains will be at its nominal pressure or above.
5. Water pressure will drop as the line is tapped off, this is why the size of the pipes decrease as we move from the drunk line to the branches, reducing the pipe size will maintain the pressure after the split.
6. The software will calculate the pipe diameter based on the sprinkler layout and the pressure from the water mains, and will spit out the 'mathematecly perfect' pipe size.
7. When building the system, you need to use pipes that are AT LEAST that size, but you can go larger.
8. You should also know the formulas for calculating GPM from pressure and pipe size, so you can confirm that the branches that have been 'upsized' to standard pipe sizes will not draw more GPM than the trunk can supply. If the branches are drawing too much water, then the trunk needs to be upsized to supply the branches.
9. The formulas are all simple math (In fact, they're the same formulas as electrical work, Ohm's Law Only with [Pressure] for [Voltage], [Flow] for [Current], and [Cross Sectional Area] for [Conductance]. [Conductance] is the inverse of [Resistance].) so the calculations are pretty simple, it just takes a few iterations to confirm that all the values are correct. Much like a skyscraper is designed from the top floor down (since the electrical, mechanical, and plumbing needs of the higher floors must pass through the lower floors, the top floor is simple, just draw what you want, then the floor below it needs to support that floors needs, and the floor below that needs to support everything above it, etc.) You would design a sprinkler system from the sprinklers back to the water main.
10. You may not be deserving all the bile and sarcasm being send your way, however, due to the many (many, MANY) people who seem to come to this site with posts like (in 'Redneck voice') "Kin ah hook up two wairs from the overhead lines to a metal swimmin hole to make a jacoozy for me an mah huntin buddies?" or (in 'Stereotypical Indian Call Center voice') "I need to connect three generators to a power grid, how do I do this, and should I worry about grounding anything?" (No information on if he is connecting to an existing grid, or if he is setting up a remote location where the generators are the sole power source. No information if the generators are Primary, Backup and Emergency Backup to the Backup, if the generators will each be running their own grids isolated from each other, or if they're supposed to be running in paralel. No understanding of power system grounding or the safe distances required to prevent people from being electricuded by just walking around on the bare soil near the power station), due to all that, the Collective Patience of the CR4 community has run almost completely dry. So now you may understand the short, snippy replies you got at the start, as to many of the CR4 community, your post might have read as 'Oh, another one of THOSE guys.'
    

#5 What's a drunk line?

I know... It was Trunk line. Or were you drinking?

I must be drinking decaf if I missed that one typo within the Wall Of Text.</sarcasm>

Part of me wants to say "Good Eye," another wants to say "Shaddup!" so I'll split the difference with a begrudging thumbs up.

Hey.... I gave you a smiley tongue out face. Isn't that enough?

I guess it goes to the fact that I truly do try to read all of the posts in the thread I replt to.

I was just giving you a poke in the ribs for your "Freudian slip" I guess I'm a bot anal on spelling even though I make mistakes, I try my best to proofread my own stuff.

When someone else makes a mistake.... Jump on the dog pile!!!!!

"I guess I'm a bot anal"

I ain't touching that one.

Cheers.

Touche!!!!!!!!!!!!!!!!

I have been a firefighter for many years and if there is one thing I have learned it is don't mess with the Drunk Line!

Drunk line (sometimes called a Draught Line) is a sprinkler system filled with beer from numerous kegs instead of water. It is used in facilities that have a reputation for hindering the response of local fire companies. This causes the interior firefighters to be hesitant about entering the burning building. The beer from the sprinklers draws the firefighters in at abnormal speeds. Once the fire is out, which may make slow progress, they do extensive overhaul and salvage (looking for fire in walls and clean up). Never shut off a drunk line until the interior firefighters tell you to, if they remember to. And never, never, never try to get a firefighter out of there if he has either a pike pole or a flat head axe in his hands.

Firefighters and beer, together forever.

Good Luck, Old Salt

Thanks for the belly laugh Old Salt.

At first I thought it was a serious reply then quickly realized the humor.

Thanks again. I enjoyed it!

Bryan