Sprinkler Designer2, How's that website coming? 3

[ContractorDave]

Just browzing thru the archives and I came across this little ditty from Jan 30, 2007:

SD2: "This does it, I am going to create a website giving detailed instruction on doing hand calculations.

Looking over the archives there are a number questions on performing sprinkler calcs.

Any designer worth his salt should be able to calculate a system using a cheap (under $20) scientific calculator, yellow legal pad, a pencil and table of pipe size/ID'S.

I did my first hydraulic calculations in 1976 well before the advent of computers. Trees were simple, loops were not hard to do and grids were not defined so starting out we didn't do those.

But you should be able ot do simple ladder grids by hand."

I'd be an interested participant! I'm looking at doing multi-purpose pipe systems: combo domestic / sprinkler set-ups ala Uponor or Rehau and I could build a calc program into excel pretty easy if I had some tutoring.

Regards

 

[SprinklerDesigner2]

I need to find time to work on it.

We got rather low on work in September so bid, bid, bid but now it appears we are getting more then I wanted and my plate is full.

But I need to finish that up.

 

[sfallows]

you can not do grid calc's by hand easily because after 2 or 3 simultaneous equations it becomes impractical

 

[SprinklerDesigner2]

"you can not do grid calc's by hand easily because after 2 or 3 simultaneous equations it becomes impractical"

I disagree. Prior to 1986 all my calculations were by hand as was most everyone else's except the large companies that purchased mainframe computer time.

Before HASS and Crowly it was the way everyone did it. I believe every designer should be able to do hand calcs because it makes you think about what is happening.

When I took the NICET one of the problems presented was calculating the loss through a grid from one end to the other. If you don't know how to do hand calcs you'll never pass it.

Trees are easy and so are loops. I might have spent an hour or two on a tree with maybe twice that on a loop.

Grids were a super pain but we'd lay out a grid to make it as easy as possible. Ladder grids with equal mains and identical feeds to each main weren't that hard to do but it was time consuming.

Granted, some of the things we do today, such as bird caging a two story building with a grid on each floor, I wouldn't even think of doing by hand.

I am working on it this weekend.

 

[ContractorDave]

Good morning SD2. I am working also this fine weekend. What reading / study resources might you suggest for understanding and applying some of this....aside from going back to school for 5 years? Quite frankly I've never heard of the phrase "Bird Caging".

 

[TravisMack]

Bird cage is often referred to when you have an apt or hotel. This works when you don't have individual floor control valves. You run your sprinkler system piping on the 1st floor, then rise up in the walls to feed sprinklers on the floors above. You typically have a series of 1" risers going up through the building. If you strip the building away, the piping network somewhat resembles a bird cage without the top.

What information are you looking at applying? Doing tree calcs by hand is easily spelled out in NFPA 13. I used to have some NICET review materials that easily explained calculating a loop by hand. I have since passed that information on to others, so I can't help with an exact reference.

Travis Mack
MFP Design, LLC

 

[ContractorDave]

Good morning to you also Travis

I can do the typical tree calcs fairly easily and have it in an excel program for 13d applications. That being said I am no math wiz and want to make sure I am doing it correctly... by doing it I mean loop calcs. I am thinking about pushing the multi purpose systems up here ( ala Uponor or Rehau) and I want to be able to do the math myself.

 

[Cidona]

I have some information from a class I took that would probably be a good help to you. I can scan them, there's around 12 pages. What would be the best way to 'get' them to you?

 

[ContractorDave]

Much appreciated! Can you attach it to a post? I believe it's somewhat frowned upon to leave e-mail adds here but if you can't attach you can find me under sprinkler division at

http://www.ykfireprevention.ca/contact.php?contact=1

Regards

 

[Cidona]

Lightecho.
I had started scanning these and then got to thinking about copyright infrigement. I noticed there is a copyright stamp so I am unable to send this to you. However the information you are looking for is in the book 'Fire Protection Hydraulics and Water Supply Analysis' - Published by Fire Protection Publications - Oklahoma State University. Lots of good stuff to keep you busy in there.
Also, the NFSA coveres 'advanced hydraulics' as part of their 'Advanced Technicain Classes'.
Both are highly recomended. Sorry for the 'reneging' on the offer.

 

[ContractorDave]

Not a problem and thank you for the information!

 

[TravisMack]

Light Echo:

If you plan on calculating many loops, you may just want to look into some of the sprinkler calculation softward. There is a program called THE which is pretty inexpensive. I believe that ELITE has a relatively cheap one as well. HASS is good, but is likely not cost effective for you. I am not sure what HydraCALC costs as a standalone, but it would be good as well.

Travis

Travis Mack
MFP Design, LLC

 

[SprinklerDesigner2]

lightecho,

One of my favorite tool is something we see everyday.

N^1.85 graph paper.

We've all seen it used to visually plot a supply/demand but it can be used to solve loops too.

http://img254.imageshack.us/img254/730/sample1kg2.jpg

In this case we have a little loop feed from Point A to Point B. Part is 1" while other side is 1 1/4" sch. 40 black steel with a C=120.

 

[ContractorDave]

Travis
Yes I've looked at a few programs. On the face of it that is the way to go.... but two years ago I didn't know a thing about Excel. Now I'm using it for everything from charting pump and hydrant flows in my reports to isometric drawings. I figure with a little bit of work I can build a quick program for calcing loops.

SD2
N^1.85 graph paper might be something YOU see everyday, and thanks for the link. I prefer visual tools usually also but the relationship here between the drwg, the math, and the pipe is not quite beating it's way into my skull... I'll get there though.

 

[firepe]

If you are looking for a book (the best book on the topic in my opinion) on the subject, I suggest "Sprinkler Hydraulics", by Harold S. Wass, Jr.

This was originally published in 1983 for/by IRM Insurance, but is now currently available in a paperback second printing from the SFPE bookstore.

 

[ContractorDave]

Thx firepe

 

[sfallows]

sorry your are right, I am piss poor at getting my viewpoint out clearly... its possible just not practical

As stated in "Fire Protection Hydraulics and Water Supply Analysis" Second Edition By Pat Brock

page 242-243

"From a practical standpoint, there is no time efficient technique for the computation of gridded designs by hand. Most people consider life too short for such a time-consuming process." ....

 

[SprinklerDesigner2]

"From a practical standpoint, there is no time efficient technique for the computation of gridded designs by hand. Most people consider life too short for such a time-consuming process." ....

That describes it better then I ever could. I did a couple grids by hand back in the early 1980's one one system spending two full weeks doing nothing but calcs.

I saved a couple thousand on the job. Was worth when a designer would work 60 hours to make half of what a fitter would make in 40. It isn't hard or involve a high level of math it's just tedious as all heck.