1.00 or 1.25 PEX line from Well

[m1garand762]

Typically the underground is polyethylene not pex. Pex is a more modern material

 

[jigs_n_fixtures]

To answer this question you first need to know how many GPM your well is capable of producing. If you can get 50 GPM out of your well then run a 2" line. If your well is only going to give you 3 GPM then do not waste your money on large pipe.
In fact, if you WANT sediment to build up in your line use a large line size that moves a minimal velocity of water.

Cleaning velocity is 3 to 5-fps. Above that you can scour your fittings and bends. Below 3-fps, you end up with particles dropping out of suspension.

 

[gary49]

I wonder why the drop pipe is 1 1/4”? The standard around here for a residential well is 1” black polyethylene both for the drop pipe and the lateral pipe to the house. 1 1/4” pitiless adapter and pipe is a good deal more expensive than 1”. Black poly pipe ratings changed a few years back, so 160psi is much thinner than it used to be, and therefore kinks pretty easily. 250psi is what I use now. I like black poly for the lateral pipe because it’s less likely to break at the foundation due to the backfill settling over time. Most of the repairs I’ve made of leaks at that point were in PVC pipe even though black poly is far and away the more frequently used pipe. Pex might be the preferred choice if one were plumbing for hot water, but well water isn’t hot unless you are in an area with geothermal activity in which case home heating and a hot tub would be the likely topic. I’d save some money and use polyethylene, it’s cheaper and the pressure rating is higher.

 

[Larry Caldwell]

I have 1.25" 125 psi black poly. Cheap and reliable.

 

[jigs_n_fixtures]

I wonder why the drop pipe is 1 1/4”? The standard around here for a residential well is 1” black polyethylene both for the drop pipe and the lateral pipe to the house. 1 1/4” pitiless adapter and pipe is a good deal more expensive than 1”. Black poly pipe ratings changed a few years back, so 160psi is much thinner than it used to be, and therefore kinks pretty easily. 250psi is what I use now. I like black poly for the lateral pipe because it’s less likely to break at the foundation due to the backfill settling over time. Most of the repairs I’ve made of leaks at that point were in PVC pipe even though black poly is far and away the more frequently used pipe. Pex might be the preferred choice if one were plumbing for hot water, but well water isn’t hot unless you are in an area with geothermal activity in which case home heating and a hot tub would be the likely topic. I’d save some money and use polyethylene, it’s cheaper and the pressure rating is higher.

You should always match the discharge on the pump, as a minimum. Most down hole pumps have a 1-1/4-inch discharge. Local hardware store stocks 1-1/4-inch, Sch80 PVC with threaded ends specifically for setting pumps. And, 1-1/4-inch pit-less adapters.

If you order a larger pump, they will offer to get the larger pipe to match the pump outlet.

It is important to size your pipe to keep the flow velocity in the pipe, between 3 and 5-fps. This velocity is a sweet spot. Low enough avoid eroding your bends and fittings, while fast enough to keep any sediment in suspension.

 

[jigs_n_fixtures]

Typically the underground is polyethylene not pex. Pex is a more modern material

Poly pipe is extruded, and the poly forms long strands bonded along their edges. As it gets surge pressures, it crystallizes along those joints between the strands and eventually splits longitudinally. The thinner the wall, the faster this happens.

PEX, stands for: Polyethylene Cross Linked. It is extruded poly pipe, which has been etched, either with small hot blades, or lasers, to shorten the strands, and increase the link to the adjoining strands.

PEX is very resistant to splitting, and will survive freeze cycles without damage. Your fittings might split but the PEX will be just fine after the water thaws. Standard poly pipe will split if the water in it freezes.

This is why when I run the new line to my place, I will install a 2-inch Black poly carrier sleeve, with 1-inch PEX as the waterline. I will run a length of heat trace wire in the Poly next to the PEX. If my service ever freezes, I will ;power up the heat trace until I get running water. By doing that, i can keep the depth of bury up around three feet instead of down at 6-ft. Which saves a lot of excavation and bedding work.

In the extremely rocky soils I have, you can dig a relatively narrow trench 6-ft top width at 3–ft, more like 12 to 15-feet width at 5-ft. I’m on a historic river bar. Lots of 8-inch plus rocks, touching each other, with sands and clays in the gaps between the rocks. Really nasty digging. Going twice as deep, moves three or four times more dirt. the stuff is unstable, and OSHA requires 1.25:1 side slope for full depth if you go past 4-ft.

 

[Pettrix]

You should always match the discharge on the pump, as a minimum. Most down hole pumps have a 1-1/4-inch discharge. Local hardware store stocks 1-1/4-inch, Sch80 PVC with threaded ends specifically for setting pumps. And, 1-1/4-inch pit-less adapters.

If you order a larger pump, they will offer to get the larger pipe to match the pump outlet.

It is important to size your pipe to keep the flow velocity in the pipe, between 3 and 5-fps. This velocity is a sweet spot. Low enough avoid eroding your bends and fittings, while fast enough to keep any sediment in suspension.

Correct. The discharge hole from the well pump is 1.25" so the drop pipe was 1.25" and the same with the Pitless Adapter.

The 1.00" PEX is Type A and rated for 160 psi. It's easier to use as it's "flexible" to a point and once in PVC conduit, it is well protected and insulated. I bury the line 24" below grade and the PVC pipe adds an air barrier which gives it a little more R-Value. The frost line out here is 18".