Calculating the water pressure in a system

If you know the flow rates from the taps what is your problem??

I need the pressure drop with the faucets open. I have a series of faucets and need to demonstrate the pressure drop at each faucet and that at the end faucet a 20 psi pressure is maintained.

Flow and pressure are two diffrent things!

If you are using a computer program Like Pipe Flow (software engineering co) or just doing it manually you also need to know the number of elbows and valves in the system. You also need to know if you have tube or pipe and the nominal dimension associated with each. for example an elbow and equal 6 feet of pipe as a measure of resistance.

What do you consider as "end of the system"? Is that pressure in front of fawcets ?

Because if the "end" is after the fawcet you have the athmospheric pressure independent of how many fawcets you open or from the hydraulic resistance of the tubing. If you open the fawcets the flow will depend on the circuit resistance so that you cannot know in advance how big a flow will go through.

To begin with- your pump will provide the pressure to operate the system the number of water appliances are the noodle on the sushi

You will need a minimum of two gallons per minute per appliance per each hotel room for seven minutes at a minimum as this is the normal delvery value used if and only if you are using water saving appliances.

So if you have a faucet and a shower and a toilet you need to be able to provide a minimum of six gallons per minute per motel room at 30 PSI so plan your storage accordingly and do not scrimp on water storage!!!!!

So you will need storage of at least 48 gallons per minute for seven minutes which 342 gallons which is the minimum you should have for storage for all eight rooms. The larger the delivery pipe the less presure/resistance you have.

So Ideally you should have a five hundred to one thousand gallon storage tank with a float switch to control the well pump, which will gravity feed to a jet pump which will deliver water to all the rooms. you will need a jet pump that delivers 50 peak gallons per minute of cold water for your facility.

Option two:

What you need a minimum of one large cold water bladder tank per room and by large I mean at least a fifty gallon bladder tank for each room to allow for pressure and refilling without effecting total system pressure.

Are you able to provide four gallons per minute of hot water per room?, this is the other question. Your water heater must be able to provide 32 peak gallons per minute of hort water continuosly to all the rooms as well. this is where a circulating pump comes into play for a hot water system- it runs only when hot water is called for with a minimum of standby heat loss.

If not you must have additional cold water storage to fed the hot water heater and hot water generating capacity to take care of all the rooms as described above.

I am sorry if this is not the answer you expected but this is what is required in new york state.

I am a certified water well driller and pump installer so please take me seriously even though I am posting annon.