Parallel PEX water lines?

[Keith_MN]

Since PEX larger than 1 inch is expensive and difficult to source, are there any issues with running parallel 1” pex lines instead of 1-1/4” Pex or 1” copper? According to my calculations, running parallel 1” pex is about half the cost of 1” copper.

I am relocating my well tank to the other side of the basement and do not want to choke down the 1" ID inch well supply pipe by using 1” PEX. Also am thinking about this for the irrigation system to avoid the pressure drop.

 

[Cacher_Chick]

I am not sure what the issue is, we have no problem getting 1-1/4" PEX.

 

[Sponsor]

 

[Keith_MN]

For a DIY home project, 1-1/4 pex does not seem practical. My local home improvement store that sells 1-1/4 PEX fittings has them on special order but in 25 pack quantities. I checked four online sources and none of them offered fittings greater than 1 inch. Also, I would need to purchase another crimper.

 

[Craigpump]

You could use 1" poly with brass insert fittings but it's tough to secure to floor joists. Another option is to use sch 80 pvc with solvent weld fittings. I'd probably go with Uponor PEX because the fittings have a larger inside diameter.

 

[Reach4]

are there any issues with running parallel 1” pex lines

Nobody has said that would be prohibited. I was wondering.

I am relocating my well tank to the other side of the basement and do not want to choke down the 1" ID inch well supply pipe by using 1” pex. Also am thinking about this for the irrigation system to avoid the pressure drop.

I think you are saying you intend to put the pressure tank farther from the well. When you move the pressure tank you need to move the pressure switch with it. Any pressure drop in that pipe will be made up by the pump.

You could tap off your irrigation, or other unsoftened water, earlier in the path on the way to the tank and switch. So just tee the line before you start the 1 inch PEX to the pressure tank+switch.

 

[Cacher_Chick]

You could use 1" poly with brass insert fittings but it's tough to secure to floor joists. Another option is to use sch 80 pvc with solvent weld fittings. I'd probably go with Uponor Pex because the fittings have a larger inside diameter.

He could, but it would not meet code in most states for indoor supply pipng.

 

[Cacher_Chick]

For a DIY home project, 1-1/4 pex does not seem practical. My local home improvement store that sells 1-1/4 pex fittings has them on special order but in 25 pack quantities. I checked four online sources and none of them offered fittings greater than 1 inch. Also, I would need to purchase another crimper.

You need to go to a plumbing supply house. Depending on the brands that are carried, 1-1/4 comes in rolls and in 20 ft sticks. If I couldn't get it, I would just bite the bullet and use copper.

 

[Keith_MN]

The pressure

He could, but it would not meet code in most states for indoor supply pipng.

I know that PVC is not allowed in Minnesota so I am guessing that poly is not either.

 

[Keith_MN]

You need to go to a plumbing supply house. Depending on the brands that are carried, 1-1/4 comes in rolls and in 20 ft sticks. If I couldn't get it, I would just bite the bullet and use copper.

So you would do copper versus double PEX lines even though pex would be half the cost and quicker to install?

 

[Craigpump]

Both poly and pvc are used regularly for interior offsets in Ct., I've never seen an inspector not sign off on it.

 

[Cacher_Chick]

So you would do copper versus double pex lines even though pex would be half the cost and quicker

The pressure


I know that PVC is not allowed in Minnesota so I am guessing that poly is not either.

CPVC, copper, PEX, and traditional galvanized piping are code approved options.

 

[Cacher_Chick]

So you would do copper versus double pex lines even though pex would be half the cost and quicker to install?

Your goal should always to be to complete a job with professional workmanship, and never to do something that screams out "hack job". Those jobs which I cannot do to trade standards get hired out to someone that can do it properly.

 

[Jason4429]

What did you end up doing? I need to run 2200' of water line from the meter to my house and have encountered the same issue. I can run parallel 1" lines for 1/3 or 1/4 of the cost of a single 2" line. Once you get above 1", there is a premium on the price and it is difficult to find (except online).

I suspect a single 1" line would not be sufficient due to the friction loss over 2200'. Would parallel 1" lines work, assuming you have the appropriate fittings/adapters at the meter and at the house?

 

[Reach4]

Four one inch lines in parallel would have almost the capacity of a 2 inch line. Two one inch lines in parallel might have less than the capacity of a 1.5 inch line. I did not consult a pipe calculator, but I think I am right on that.

For burial, you would probaby go with HDPE (high density polyethylene) rather than PEX for less money.

 

[Jadnashua]

If you need the capacity of a 2" line, two 1" lines is NOT the same!

Area of a 2" opening 3.14 (1^2*pi), area of one 1" pipe opening 0.5^2*pi *2 (for two pipes) = 1.57, or less than half the size. You'd need 4 1" pipes, and then each would have much more friction over their length than the single, larger diameter pipe with the resulting frictional losses.