Is there a means (tool) to reduce the pressure ?

[ifran31]

Good morning everybody,

I have a piping design which has the following data:

1) Main piping: DN 150 and 11 bars pressure
2) secondary piping: DN80, 11 bars pressure

water arrives from piping DN150 and feeds the DN 80 system ,as shown in the enclosed diagram,

Each sprinkler supports a maximum pressure of 3.5 bars,

My question is:

Is there a means (tool) to reduce the pressure from 11 bars to 3.5 bars?

If I keep the design as it is, will my sprinklers bear a pressure increase?

Thanking you in advance
I remain,
Sincerely yours,

 

[C2it]

Are you new to piping design ? Maybe a student ?

Answer 1 ... pressure reduction is usually by control valve(s) with associated protection from over-pressure.

Answer 2 ... Only you can answer this one, it depends on the allowed pressure for sprinklers, pressure stress in pipe etc.

 

[123engr]

C2it is right to inform you that the pressure reduction can be achieved by control valve.

I am what I am by His grace

 

[bimr]

A self contained pressure reducing valve is used for that purpose.

http://www.documentation.emersonprocess.com/groups/public/documents/reference/d351798x012_02.pdf

 

[Latexman]

What do you mean "Each sprinkler supports a maximum pressure of 3.5 bars"? In my experience, sprinklers are usually good for 34.5 barg or more without leaking water. Are you confusing this with the minimum pressure to support good sprinkler flow?

Is your system a "wet pipe" or "dry pipe" sprinkler system?

Good luck,
Latexman

 

[bimr]

Multiple valves will be a costly alternative. You would be better served if you selected spray valves optimized for your applicatoin:

http://www.spray.com/spray_nozzles/standard_spray_nozzles.aspx

 

[ifran31]

Hi,

Thank you for your effective cooperation.

I am a mechanical engineer (thermal) trying to dimension a fire protection hydraulic system for a friend.

Regarding my previous questions, I am going to use a pressure differential on upstream DN 80 piping system (here is enclosed pdf file),

For protection, I use a SPRAY sprinkler to protect a storage shed box. In accordance with APSAD R1 standard (European Standard), each sprinkler protects an area of 12 m2 with a maximum pressure of 08 bars (manufacturer’s data), the bursting temperature of the sprinkler is 68 ° C.

By the way, the system used is the “wet pipe »,

Based on your experience, I plan to fix a deluge valve to stop the water in the DN 80 pipe after using a sprinkler, but the pipe (DN 80 ) is installed 6 meters above the ground. if I choose a DN 80 motorized valve, do I solve the problem?

Is there a more effective method than that of the motorized valve?

Thank you for your help.

Awaiting your reply,
I remain,
Sincerely yours.

 

[BigInch]

Fire is a serious critical safety installation. Shouldn't you feel some ethical responsibility to advise your friend that you are not qualified to kill him and others, thank him and pass on your irresponsible enterprise to an engineer that IS QUALIFIED to do the work.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[Latexman]

For a "wet pipe" system, it's obvious you do not know what you are doing. I second BigInch's advice.

Good luck,
Latexman

 

[ifran31]

Biginch hello,

Actually, the fire is a very serious problem, which is why I chose the code.

For industrial safety, without the code you can’t make a design of a reliable installation,

In my previous mesages, when I told a friend, this is not a joke, it's legal contract between us,

I do not use this forum to solve my technical problems, but to solicit the design ideas that I do not know,

Thank you for your advice,

 

[BigInch]

"but to solicit the design ideas that I do not know"

Listen to yourself. "Qualified" means you do know, but it seems you don't.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[Latexman]

bimr,

I'm not so sure about using a self contained pressure reducing valve. A "wet pipe" system is normally a dead-ended system, i.e. no flow. If the regulator starts to leak downstream (age, defect, damage, etc.) the downstream pressure can get quite high, up to the upstream pressure. In this case with 11 bar supply and 3.5 bar sprinklers, that may be problematic.

Good luck,
Latexman

 

[Latexman]

C2it and 123engr,

See my post on self contained pressure reducing valve. Ditto on the control valve on a dead-ended system. Leakage will cause a pressure problem. Agree, or not?

Good luck,
Latexman

 

[EnergyMix]

ifran31

I don't have a lot of knowledge about fire protection systems; however, I don't think what you're proposing is the right sort of design. Here in the States what I hear a lot about is something called "fusible links" and a code called NFPA (National Fire Protection ??) (a coworker is getting an advanced degree in fire protection and bends my ear a bit on it.) I would suggest that you might want to look into this a bit more and make sure you're following the right codes. There is a fire protection forum here on Eng-Tips that might be helpful, but there's no substitute (as others have mentioned) for a qualified design.

 

[Latexman]

Excellent advice EnergyMix!

I would like to add two things.

In forum184 , learn to use the Search function (between Forum and FAQs near the top, left of thread) to search in that forum only, on subjects and keywords that will advance your understanding of the fire protection design, like "sprinkler", "sprinkler system", "sprinkler system design", "fusible link", "wet pipe", "wet pipe design", etc.

In the U.S., fire protection systems must be approved by the local authority. They usually require the calculations and drawings be approved and stamped by a qualified fire protection engineer. If this is true for your project, have you planned for it?

Good luck,
Latexman

 

[bimr]

Latexman,

The prv was suggeted based on the preliminary information that did not include the knowledge that this is for a fire system. That suggestion is no longer appropriate.

I agree that with the other posters that a fire system should be designed by someone with some experience in that field.

 

[waross]

each sprinkler protects an area of 12 m2

That's a maximum. There may be factors which reduce the coverage area significantly.
Hire a professional.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

Based on your experience, I plan to fix a deluge valve to stop the water in the DN 80 pipe after using a sprinkler,

A deluge valve is used to start the flow, not stop it. Some deluge valve designs are incapable of stopping the flow of water.
Hire a professional.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ifran31]

Good morning,

Thank you for your best suggestions, I will apply for this project.

Regarding our organization in this project, we are a team in several specialties (Process, HSE, mechanical, electrical, instrumentation and civil engineers) who work in accordance with interface engineering procedure.

Finally, thank you very much,

Sorry for my English because I am beginner,

R.B (Mechanical Engineer)
"Tu me donne une idée, je te donne une idée, nous avons chacun deux idées"