what is the maximuin water flow through 1 inch copper at 50 psi

john_236

Designing a body shower and I am looking at either a design the will require 10 GPM or 17.5 gpm flow rate is it possible with 3/4 or one inch pipe. Thanks

bruce_21

From appendix E of my '95 IPC book, 1 inch copper tube will give you almost 20 gpm at a pressure drop of 10 psi/100 feet of pipe, the velocity will be high at about 7-8 feet/sec. This is a kind of maxxed out situation. I'd go up to inch and 1/4 and feel better about it all.

Henry

I would worry very much about being able to produce hot water for those type of applications. You would ned in the summer at least 5 gpm of hot water or 300,000 BTU input hot water tank! We use for the high priced housing market a Cyclone Xi BTH300 with great succes. We have never had a client complain of lack of hot water or of expensive gas bills!

scrook_2

same as...

at 5 psi or at 500 psi!

Issue is velocity, not pressure, though use too small a tube/pipe and the pressure drop will limit the flowrate.

I wouldn't exceed these by too much:

5-6 GPM for 3/4"

8-9.5 GPM for 1"

13-15.5 GPM for 1.25"

18-22 GPM for 1.5"

Also a commercial sized water heater or boiler/indirect tank to feed it!

radmix

Plumbing flow rate

I have an existing farmhouse feeding domestic water to an existing hotel. The hotel has ten rooms. The owner has told me that there were 2 other buildings on the property that the well in the house was feeding  but were demolished at some point. The pipe size of the copper going to the hotel is 1" with approximately 40" of linear pipe. The pressure on the pressure tank is at 100 psi.

 I believe they kept the pressure on the tank at 100 psi to feed all three building at one time. My question is, How many GPM will I get from a 1" copper pipe at 100PSI on 40' of pipe.

Zman

Flow rate

I think the max flow rate for cold water that most codes allow is 8 feet per second. At that rate you could move 18-22 gpm depending on the wall thickness of your pipe.Ideally you would not move it that fast as it could wear out your pipes. I think the flow rates in the above post is a better idea (about 6fps).

The pressure drop at those rates should not be an issue (less than 5psi).

If you are wondering how fast the water could move through the pipe,if you left the end open. The answer is ALOT!

Carl

radmix

GPM

I'm asking this question because the owner is installing 6 kitchenettes that the building DEPT. is now requiring a Fire sprinkler system for the hotel. I need to know the max amount of gpm is scenario will  produce.

Zman

Fire Protection

Fire systems are a whole different game.

In most areas the whole thing including the well and pump need to be designed by an engineer.

I think it is safe to say that your 1" line will not be big enough.

radmix

Fire Protection

 I had an engineer design the system. It calls for a 1" line from the well coming into the hotel which is small. But it calls for 25 GPM from this 1" line. Is there a formula that can tell me how much gpm I can get with100 psi with  40' of pipe.

Zman

The engineer...

Should calculate all this. He should also look at the capacity of  the well to see if it can keep up.Since the well is also a fire pump it may need to be wired differently.

He should have already looked at this as his system should be designed based on available GPM and PSI.

Carl

SWEI

Fire sprinkler calcs

are different, and definitely part of the engineer's job.  He can choose from a huge variety of heads, with a range of coverage patterns, flow rates and areas depending on pressure.  Is this a 13R job?  If not, you might consider what occupancies he is designing to and perhaps engaging the architect and/or the fire marshal to see if you can veer them off of 13, at least for the guest rooms.  I've done it and saved a pile of money.

icesailor

100# water pressure:

First of all, most all well tanks, old and new, are rated for a maximum working pressure of 75# and have 75# pressure relief valves on them. You are NOT supposed to run a well system at 100#. You can have a submersible pump deep in the ground that will develop far more than 100# to push the water up high enough to give the desired pressure, but that's not what the working pressure will be. You can't be using 100# in a water well system unless the system is designed for it. Most codes require a Pressure reducing Valve if the working pressure is over 75#. Or so I have been tested.

Fire systems:

Where I worked, in outlying areas where there was no municipal water and all water was well supplied, and someone came along that wanted to build a structure that needed fire sprinklers, the system had to be designed by a Mechanical Engineer or a Professional Engineer. And when it was done, the only way they got around it with wells was to have fire pumps and stored water. Along with an emergency stand by generator. Usually a number of concrete septic tanks used as storage tanks. At least 10,000 gallons worth for storage and if the electrical system goes down.



There was a large old hotel, built in the 1900's, way out of town that had its own village water system. It was sold and a large renovation was done. It triggered fire system upgrades. There was no grandfathering. They had to install a large number of concrete tanks for emergency water storage use in the fire system.



Maybe where you are from, you can get away from it. I'd be checking with the insurance and building departments to see what current codes require. A lot of these projects will trip MCD requirements.

I've seen it for years. Enraged neighbors come out of the wood work to stop these improvements. Just reality.