Material and fittings for fire protection system 3

[insitebuilders]

We are preparing a building information model in which the fire protection system is in the background of the primary model images. The model includes a number of visually accurate representations of mechanical systems.

But we are finding conflicting info on the piping materials used the installation of the fire protection system.

In a typical (basic) installation, can anyone pls clarify the requirements for pipe materials for a five story office building (<50k sf)? I note that piping can be steel, CPVC, copper, etc. CPVC seems to be residential, steel most common?

I also find grooved and threaded connections in the service branches. Are grooves and couples preferred or required? Or are these fittings more for industrial applications.

Thx for any help.

/Dennis

 

[TravisMack]

grooved or threaded branchlines simply depends on the structure of the building and what is easier. If you have long straight runs, it is often easier to groove the full sticks and have welded outlets for the heads. If it is really cut up, you will likely see threaded branch lines. The mains will likely be grooved unless you are in an old building with threaded 8" sch 30 pipe. That was when the fitters were MEN!

 

[insitebuilders]

Great, thx. We'll show steel w/ couples and full sticks of grooved pipe.

Can't imagine what a wrench would look like to turn an 8" threaded pipe. Let alone the men...;-)

Thx again

/D

 

[stookeyfpe]

Travis is again correct. Victaulic fittings + weld-o-lets properly prepared in a good piping job shop is the method of choice. And it meets NFPA 13.

 

[insitebuilders]

Thx for the tip on the weld-o-lets. We were beginning to model the strap outlets by Tyco/Grinnell and wondered if the tap holes we're drilled in the field w/ a special tool. Drilling and welding in a shop makes a lot more sense.

Just out of curiosity, does that mean the entire assembly is precut, predrilled, welded and prefabricated? And is the "pipe shop" a certified fabricator that tests the pipe or a machine shop owned by the FP company that does the same...?

Thx again to both of you for the time you take. We've read and printed many of your threads and learned a lot about FPE from your work.

 

[SprinklerDesigner2]

"Just out of curiosity, does that mean the entire assembly is precut, predrilled, welded and prefabricated? And is the "pipe shop" a certified fabricator that tests the pipe or a machine shop owned by the FP company that does the same...?"

Yes. If done properly (perfectly?) the pipe should go together like a set of tinker toys the men never having to cut a piece of pipe. Of course this never happens but we do get close at times.

Fabrication shops are not "certified" except for welding operations. Most shops use a fabrication service but some do in house fab as well.

Of course there are as many ways to do this job as there are layout technicians and being a multi-story building the building code probably requires a standpipe which will, more then likely, require a fire pump. With a fire pump I would imagine you would have 150 psi which means "mains" will probably be 2" pipe or less while "branch lines" would most likely be 1 1/4" or 1 1/2" at most.

Using quick response sprinklers, which are required to be used in light hazard occupancies, the area of application could be as little as 900 sq. ft. which will result in much smaller pipe then most people might envision. Matter of fact I am working on a 5 story building right now and the largest piece of pipe I have on the second through fifth floor is 1 1/4" and I still have a 40 psi "safety factor".

I would look at using Flex Heads

http://www.flexhead.com/

which would allow my lines to be straight with few fittings, tees and elbows. Using the flex heads makes it easy to center sprinklers in ceiling tiles and solves a number of problems if in an area where earthquake protection is required.

 

[insitebuilders]

Interestg. A fire pump and stand pipe are being included but the sizes and pressures don't really matter to the overall 3D model. In fact a little oversize is a better for the technical illustrations that we'll extract from the model. But it is interestg to a non-FPE that the pipe sizes are smaller than I would have guessed.

And the flexheads are a real find, we'll be certain to include them. They look like threaded connections at both ends. Thanks for the link.

 

[SprinklerDesigner2]

"I also find grooved and threaded connections in the service branches. Are grooves and couples preferred or required? Or are these fittings more for industrial applications.

In my opinion schedule 10 lightwall pipe with grooved fittings is superior to the heavier schedule 40 pipe with threaded ends coupled by threaded fittings.

Sure, schedule 40 is heavier but where the problem is going to be, if there is ever is one, will be at the threaded fittings. It should be noted after the thread is made the actual wall thickness of schedule 40 pipe is less at the threads then the standard wall thickness of schedule 10.

35 years ago almost everything was installed using schedule 40 pipe on pipe schedule systems with threaded fittings. The pipe schedule is where you could feed 2 heads with 1" pipe, 3 heads with 1 1/4" pipe, 5 with 1 1/2", 10 with 2" and so on.

A branch line might look like this.

------x--------x--------x----------x--------x------x------x
2" 2" 1 1/2" 1 1/2" 1 1/4" 1" 1"

Pipe sizes got wildly huge in a hurry. I remember doing "take outs" for 8" threaded fittings (I don't know if you can even buy these anymore) and it would take all day for two men to hang 50 feet of main in an open building.

Today everything is calculated and pipe larger then 4" on a standard building is very rare. Thing is, though smaller pipe is used, the performance in better in many cases. We've all run hydraulic calcs through pipe schedule systems and though the riser be 8" most of the time we can demonstrate the ability to deliver more water to the fire using smaller pipe. Everyone should remember the old pipe schedule was developed back in the late 1800's and with the exception of dropping 3/4" pipe has remained virtually unchanged for 100 years. Does anyone build buildings like they were built 100 years ago?

Old time fitters would develope their own pipe dope because a leak at an 8" fitting was always a big deal to fix. I remember one, we nicknamed him "Turtle" because he looked just like the cartoon turtle on a can of "Turtle Wax", who took standard pipe dope, added some linseed oil and two pipe dopes developed for boilers. After a couple years this stuff would harden to where you couldn't back a fitting out. For 20 years after Turtle retired I would send fittings out to modify an existing system and whenever they learned The Turtle was the original installer a collective groan of displeasure would erupt from the entire crew.

"Chain tongs with an 8' cheater bar". I wonder how many fitters alove today would even recognize one.

 

[insitebuilders]

After 30yrs of this industry, I also often thk of all the Turtles I've known (always with a smile..) But I often wonder if those were the good ole' days or just fondly selective memories..;-)

 

[DavidCR]

I don´t know if I´m not reaching the main point of your question but for illustration purposes, in general, to have a easier way to visually identify the most common fire protection stuff, I would suggest to use:

Exposed pipe:
Diam: 1 1/2" or less, threaded (malleable or ductile iron fittings like you´ll find on anvilintl.com).
Diam: 2" or larger, grooved or butt-welded.(Just in case: victaulic.com has some software with drawings on grooved stuff). Grooved can be found from 1" or larger but it is a more modern use and theaded is more comon for 1 1/2 or less. Carbon steel is IPS,ASME B36.10 diameter basis (the most common).

Branches from Diam 2" or larger main), mechanical tees.
Brass: accesories which in general are hose valves, and fire dept connections, etc. are mostly 1 1/2", 2 1/2" threads, also 4 1/2" and 6" is common american hose thread (known as NST or NH type).
Where PVC is accepted for sprinklers it is orange with cement or theaded joints.
For the illustration of fire prot approved support accesories, seismic bracing and fixtures take a look at Tolco/Nibco webb site with include some cad drawings.

Buried pipe:
Pipe: AWWA C900 pipe light blue color, with push on type joints with simmilar pipe.
Other option for pipe would be to illustrate it with ductile iron pipe (black tarr color).
Fittings: Black ductile iron compact mechanical joint fittings (e.g.tyler union fittings, star pipe, etc.).
Cast iron hydrants of a private main: red (if connected to a municipal main yellow or other, check on c).
PVC/DI goes frm 4" and larger and the diameter basis is different from the steel B36.10 standard.

Hope this helps.

 

[insitebuilders]

David

Thanks for this reply. We've shown grooves and couplings in the standpipes, weldolets at the sprinkler stems, brass at all hose connects and PRV valves, and will now show std threads at the branch joints, that should cover all possible materials in the FP piping.

Bldg a 3D model of the FP controls, test, backflow, p-gauges, drains, gates, pumps, etc has been a real challenge. Had no idea all this hardware was part of "simple" FPE...)

Thx again.

/D

BTW not sure what the stars are all abt, but I went back and thanked everyone w/ a star.

 

[TravisMack]

insite:

I do fire sprinkler drawings using AutoSprink. It is a fully 3D fire sprinkler design program. I likely have most of the parts and such you are looking for in your drawings. I can throw together a simple drawing with hose valves, drain valves, a PRV station, cross mains, branch lines and sprinklers if you want, and export it to DWG format.

However, I don't know how to get it to you. Giving out email information is against the rules of this board. That is to keep out the spammers.

 

[insitebuilders]

That’s a really kind offer, but way too much to ask of your time. However I’d really be interested in seeing what a FP model looks like for any proj you might have laying around.

The FPE model I’m building is for the last few pages of the plumbing chapter in a new book on mechanical systems. This book follows one we published last year on the structural frame of the same 5 story bldg.

I use SketchUp in these books -- .dwg compatible -- but the program is more illustrative than engineer oriented. Not sure of the value to a pro FPE, but the models are piece based and I’d be happy to share components w/ you (or others) if you happen to use or want to try SketchUp (Google put out a free version recently). Just Google Insitebuilders to find me.

Thx again for all the help

/Dennis