How do you size a water line?

Three Steps to Sizing Plumbing Piping Systems

  1. Add up the total number of water supply fixture units (wsfu) required in the facility.
  2. Estimate demand using the table from the IPC that correlates wsfu to expected demand.
  3. Size the pipe using demand vs. friction loss curves found in the IPC charts.





How far can you run PVC pipe?

PVC must be supported every 3 ft. for trade sizes ½ inch through 1 inch. The support distance increases as the conduit size gets larger. For example, 2 inch PVC conduit can be supported every 5 ft; 6 inch PVC conduit can be supported every 8 ft.

What size water line should I run to my house?

In the case of a three family house an 1 1/2″ service line is typically required. Again the exception would be if the length of the run of pipe was only 35′ or less. In most cases a six family house or greater will require a 2″ water service line.

What size pipe is a water main?

The most common pipe diameter for water mains is 6 to 16 inches, with 8, 10, and 12 inches also being used. Branch lines providing service to individual homes, offices, buildings, and businesses vary in size from as small as half an inch in diameter up to 6 inches.

How long can you run a water line from a well?





Different well pumps can push water different distances. For example, a well pump with a single line tends to push water a maximum of 25 feet vertically. Comparatively, shallow well pumps can push water 30 feet vertically.

What kind of pipe do you use for buried water lines?

High-Density Polyethylene

High-Density Polyethylene (HDPE, often just “PE”) has become one of the most popular choices for underground service lines, thanks to its corrosion-resistance, durability, and competitive price. Some codes require that buried plastic lines under 2″ in diameter be PE (rather than PVC).

How far can you run 1 PEX?

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.

What is a normal gpm for a house?



about 6 to 12 gallons per minute

How Many Gallons Per Minute Do You Need for Your Home? This is a loaded question, that really comes down to preference and the number of individuals that are in the home. The average household needs 100 to 120 gallons per person per day, and a flow rate of about 6 to 12 gallons per minute.

What size hole should I drill for 1/2 PEX?

Youtube quote:With an inch wide drill bit will be large enough for suspension climb the extra room is also important because pipes. And tubes will expand. And contract some changing temperatures.

What size PEX should I use?



PEX is available in 3/8- to 1-inch diameters. It’s a good idea to install 1/2-inch or 3/4-inch PEX for your main lines for adequate water flow. When replacing old water supply lines with PEX the standard is to use the same size plumbing, although you can transition from 3/4-inch to 1/2-inch plumbing with an adapter.

How many fixtures does 1/2 PEX have?

We recommend you create a cheat sheet for your respective pipe sizes, so you don’t have to search for them later. For our example, our 1-inch pipe can have up to 30 fixture units, our 3/4-inch can have up to 14, and our 1/2-inch can have up to 4.

Should I upsize PEX?

There is a rule of thumb among contractors that when swapping out copper pipe for PEX the safest thing to do is upsize the PEX tubing. The thinking behind it is that replacing ¾” copper with 1″ PEX is a no-brainer way to ensure adequate pressure and performance.

Can I run 3 4 PEX to shower?

Your shower valves natural reaction will be to lower the pressure. Old school valves will just make it cold. So a bathroom should get 3/4″ and branched to 1/2″. You can branch to 3/4″ to shower depending on the valve you get.

How do I calculate plumbing pipe size?



1 inch= 25.4mm, 1 ft. = 304.8mm, 1 gallon/m=3.785L/m. Water velocity should not be greater than 2.438m/s at valve seat to prevent noise and erosion. So, Pipe area should be at least equal to water flow rate divided by eight.