Pvc pressure drops
 

Aight For the guys who know more about this type of stuff .
Ive got 300 foot half inch of sch 40 pvc I need to run a line 125 foot to the the house from a well . The well puts out 6gpm. 40 on 55 off psi Its a jet pump thats as high as it goes so cant turn it up any higher. I used a calculator for figurein. At 6 gpm it shows 19.9536psi drop 6.33453 ft/sec and at 3gpm it showed 5.45136 psi drop and velocity at 3.16726 ft/sec

A 1 inch line is comein from the pump to the pressure tank and to a outlet.

If i ran 2 lines of 1/2 pvc 6gpm at the house would both lines get around 3 gpm and give me my 50 psi . I know that bigger pipe is better suited . But with 300 foot of pipe . Its just layin in my yard so i can put it to use.

Use the bigger one inch pipe. Less costly, less pressure drop - even with two smaller lines.

Steve

I have 300 ft of 1/2 pipe layin around. And its going to be temporary use I didnt want to buy any pipe when its layin there unused . Later im going to be runnin off a completely different water well. Will only be usin this one 6 or so months. What i was mainly wondering is would it work out to me havein about 6psi drop by runnin the 2 half inch pipes with 6gpm divided between the two so 3 gpm each pipe.

http://docs.engineeringtoolbox.com/d...ss-diagram.png

Looks like 1/2" @ 3GPM ~ 3.8psi/100'
3.8psi x 125'/100' = 5.7psi, so your 5.5psi value checks out.

Usually when you add a parallel line, I'd expect the pressure drop to be halved. But you already calculated the pressure drop based on the halved flow rate, so it should be about 5.5 psi drop.

You will see some pressure drop at the tees, PVC - Equivalent Length Friction Loss in Fittings, but it's insignificant.

I used this calculator

Calculator: Pressure Loss through Piping for Water | TLV

I searched online for someone who may have did it b4 but couldnt find any one . And wasnt sure if it would work like i was thinkin or not.

Im guessin that most of the time during the day i wouldnt have as much of a drop . Until someone turned on both faucets flushed the toilet and was runnin bath water . Then i may would loose the water pressure .I mainly wasnt sure if id have a massive water drop.
I ran a water hose with a washin machine hose to the faucet it gave ok pressure but toilet wouldnt fill up until i turned off all the faucets inside the house.

I have roughly 120 feet of 3/4 poly pipe to the house and the loss of flow rate is certainly noticeable. My pump pressure is about 40 on and 50 off.

Two pieces of 1/2 have less cross section than one piece of 3/4 and more friction surface area. Think it as a built-in water saver feature. I can stand in the shower for 20 minutes and never run out of hot water or pump the well dry.

If it's only six months you can live with it.

Run two pipes in parallel.