For instance, According to Dan Holohan (author of some of the best Hydronic books any DIY person could read) you size the pipe diameter to the flow you need, then size your circulator head for the lenght of pipe you need. So, if you need to flow 4 gpm, use 3/4 inch or larger.
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For decades, copper pipe was the best option for water supply lines -- it didn’t contaminate the water as older lead pipes did, and it resisted corrosion. While copper is still useful for plumbing, cross-linked polyethylene, or PEX, is quickly becoming the water supply pipe of choice for residential systems because it’s affordable, flexible and do-it-yourself-friendly. When combined with a manifold system, PEX eliminates splicing and reduces the risk of leaks. PEX comes in various sizes to accommodate water pressure and your individual household fixtures.
PEX Diameter
When you're buying PEX, the important number is the “nominal” size. This construction standard indicates the pipe is compatible with fittings of the same size. The flexible tubing comes in rolls of 50 feet up to 1,000 feet. PEX tubes range in diameter from 3/8-inch to 1-inch for residential applications. For adequate water flow, it's a good idea to install 1/2-inch or 3/4-inch PEX for your main lines. The standard when replacing old water supply lines with PEX is to use the same size.
Manifold System
Because it’s flexible and continuous, plumbers can run PEX tubing from a water-supply manifold directly to each fixture. Whole-house residential manifolds typically have blue valves on one side and red valves on the other, indicating hot and cold water lines, respectively. When running water supply lines, the general rule is to go from a wider line to a narrower line, but not the other way around. The valve sizes on the manifold indicate the largest compatible PEX tube size. For example, if the manifold has 3/4-inch valves, you can install 3/4-inch, or smaller, PEX tubing. Reducer fittings are necessary when you need to install tubing narrower than a manifold valve.
Water Pressure
Conserving water is an admirable goal, and by running narrower PEX lines to some fixtures, you can reduce wasted water -- but not all fixtures benefit from narrower lines. Most homeowners aren’t willing to wait 15 minutes to fill their bathtubs, so running a minimum 1/2-inch line to the tub is a good idea. Other fixtures that benefit from 1/2-inch lines are washing machines and dishwashers. Sinks and showers are water guzzlers, and you can conserve by running 3/8-inch lines to them. Because the rate at which a commode tank refills is usually not important, it’s okay to run 3/8-inch line there as well.
Pressure Drop Considerations
In general, the greater the distance from the manifold to the fixture, the wider the PEX tubing should be. A 3/8-inch line is sufficient for lengths up to 250 feet; 1/2-inch line will deliver adequate water pressure up to 350 feet; and 3/4-inch tubing is necessary to run a 500-foot line. Look for a maximum recommended lengths specification on the PEX packaging.
References (3)
About the Author
Glenda Taylor is a contractor and a full-time writer specializing in construction writing. She also enjoys writing business and finance, food and drink and pet-related articles. Her education includes marketing and a bachelor's degree in journalism from the University of Kansas.
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The standard formula to calculate flow(GPM - gallons per minute)from a CIRCULAR orifice is:
29.7 * (the square root of the pressure) * (the square of thediameter of the flow orifice)
EXAMPLE using 3/4' Pex Pipe(actual I.D. of 3/4 PEX Pipe is.677') and 40 PSI pressure:
29.7 * 6.325(sq. root of 40) * .458(the square of theI.D. 3/4' pipe) =
A GPM of 86.03
Note: You also need to account for fittings in the losscalculations; while minimal several fitting will make adifference.
How much water flow through one quarter inch pipe?
What is flow of water through a half inch copper pipe at 60 psi?
How much water does a 5 inch pipe hold?
Do you mean a fixed length of 5 inch pipe or are you asking to the amount of laminar flow through a 5 inch pipe? There is not enough info here to answer. Need length of pipe and what you are asking. Read More
How many gpm of water flow through a one inch pipe at 50 psi?
How much water will flow through 1.5 inch pipe?
How much water will flow through a one inch pipe in an hour if the flow is not restricted?
question cannot be answered because it depends on the water pressure Read More
How many gallons will flow through a 12 inch pipe at 50psi?
That depends entirely on the viscosity of the liquid in the pipe ! Water would flow faster than oil ! Read More
What is the flow rate of water through a 0.5 inch pipe at 25 psi?
How much water can flow through a 6 inch pipe at 50 psi?
Water flow rate half inch PVC pipe 65 psi?
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Can you flow 40 gpm through 1 inch pipe?
How much water can flow through a 18 inch pipe 15 mile long?
Depending on the time allowed, all the water you want. Read More
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They both are constant..Water flows through a pipe but electrons flow through a wire. Read More
What is the maximum flow through 1 inch pipe?
When pushing water through 'rural class B poly pipe' The maximum flow you can achieve is 80lpm. However if you have the pipe running for 100m in length you loose 30lpm through friction loss. So at the end of the 100meter pipe you would only achieve 50lpm. Read More
What is flow through half inch pipe?
Depends on what's flowing (gas or water or something else) and under how much pressure. Read More
4 inch drain pipe water flow in gpm?
What is the maximum volume of water which can flow in a 1 inch diameter pipe?
The answer really depends on the length of the pipe. Read More
Max water flow in 1 inch PVC pipe?
Maximum PSI rating is on the outside rating of the pipe Read More
Can you flow 25 gpm through 1 inch copper pipe?
How many galleons of water can be pumped through an inch and a quarter copper pipe?
As many as could flow through before eroding the piping to the point of no more flowing through and it simply spewing about. Read More
If flow through a 10 inch pipe is 722gpm what Is the Volocity in feet?
A pipe that is 10 inch would have the velocity of 2.75 feet. This is 2.75 feet with 722 GPM. Read More
What is the flow volume difference between 1.25 inch vs 2 inch pipe?
If the flow velocity remains the same the flow volume will increase by the square of the diameter ratio. (2/1.25) = 1.6 = diameter ratio 1.62 = 2.56 more flow volume through 2 inch pipe compared to 1.25 inch pipe. Read More
How much water can flow thourgh a 8 inch pipe?
If you wait long enough, a lot of water. Read More
How much water can be pumped through a half inch pipe?
Given enough time the entire ocean could be pumped through a half-inch pipe. Read More
How much water per second will flow from a 1.5 inch pipe?
How many gallons per minute will flow through a 2 inch pipe at 60 psi?
How many gallons per minute will flow through a 72 inch pipe?
.75 inch pipe 5 psi how much is water flow rate?
How much water will be delivered from a half inch pipe at 100 psi?
More, depending on how long you allow the flow to flow. Read More
What is the water flow rate in a 24 inch diameter pipe in gallons per minute when the flow velocity is 3 feet per second?
what is the discharge flow of 10m/s passing from 2ft pipe Read More
How many gallons per minute will flow through a 1 inch pipe at 0 psi?
0 gallons per minute will flow threw any pipe at 0 psi. Read More
How many gallons per minute will flow through an 8 inch pipe at 10000 psi?
How many gallons per minute will flow through a .75 inch pipe?
What is the flow rate of water through a 20 inch pipe at 2500 psi?
For laminar flow? For a full pipe? for a 3/4-full pipe? For a 1/2-full pipe? It all makes quite a difference. Please repost your question with a little more information. It would also help to for us to know the coefficient of friction of the inside of the pipe. Read More
How many gallons of water flows through half inch pipe?
It depends upon the velocity of flow and thus how much dynamic pressure you have. The length and type of pipe/hose will also contribute to the amount of friction, further reducing the velocity, pressure and available flow at the outlet. Read More
Can you liquid flow through a pipe?
of course liquid can flow through a pipe? Read More
How many gallons of water will flow through three quarter inch pipe in a sprinkler system?
It depends on the pressure and the time frame. A billion gallons, if you wait long enough. Read More
How much water will a twelve inch pipe move per second?
Depends on the diameter of the pipe and the speed at which the water travels through it. Read More
What is the maximum amount of water that can flow in a 2 inch pipe one half mile long?
Insufficient information, one needs to know the pressure of the water entering the pipe, the relative heights of both ends the pipe, the pressure of the water at the discharge of the pipe, the geometry of the pipe including the number and types of turns, and the pipe material or internal friction coefficient. Then you can calculate the flow. Read More
What is volume of flow in a 3 inch pipe?
One inch diameter pipe with sixty PSI reading you would like to know what your water flow rate will be?
How many gallons per minute will flow through a 2 inch iron pipe at 65 psig?
How much water goes through a one inch pipe with 60 psi?
What is the difference between ampere and volt?
Liken volt and amp to a water in a pipe. Voltage is the water pressure in the pipe and amperage is the water flow through the pipe. They are two completely different electrical units. Read More
What is the difference between a volt and an amp?
Liken volt and amp to a water in a pipe. Voltage is the water pressure in the pipe and amperage is the water flow through the pipe. They are two completely different electrical units. Read More
What is the difference between amperes and volt?
Liken volt and amp to a water in a pipe. Voltage is the water pressure in the pipe and amperage is the water flow through the pipe. They are two completely different electrical units. Read More
How much water flows through a 1 inch pipe in 1 hour?
This can vary with the local water pressure. It decreases with pipe length and building elevation. Read More
How many gallons per minute will flow through a 2 inch copper pipe at 60 psi?
How many gallons per minute will flow through a 3 inch pipe at 50 Psi?
What is the rate of water flow through a 100mm diameter pipe with 300mm head pressure?
300mm is a very low head, you can't expect much flow through that pipe, but you can work it out from the mechanical energy balance equation. Read More