Questions on mix of 2" and 1.5" PVC

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J

jfmorris

0
Jun 4, 2013
73
Huntsville, AL
I'm in the middle of relocating my pool pump, filter and SWG that have been out in the yard about 10 feet off the corner of the house, approximately 10-12 feet in order to be up against the end of the house, so that I can add a pool heater to the mix, and have the natural gas more readily available, as well as have everything out of sight.

The entire pool was plumbed with 1.5" PVC, so that is what I've kept at the pump and filter over the years, even as I went through different filters and pumps. There are two supply lines - one from a skimmer and one from a main drain - that come in to a 3 way valve, then that goes to the pump. The Variflow multiport valve on the side of the Hayward DE filter has 1.5" threaded fittings, currently with 1.5" PVC glued into male threaded adapters. There is a SINGLE 1.5" return back to the pool, to supply two return jets - one at the deep end and one at the shallow end. From my digging, it appears that the 1.5" return line splits under the concrete pool deck somewhere, likely at the deep end return, then runs around the end and side of the pool to the shallow end return.

The new pool heater - a Hayward 250k BTU unit -has fittings for 2" or 2.5" pipe, depending on whether you use the outside or inside of the fittings. But I am plumbed to 1.5".

I realize I could buy replacement union/fittings for my pump, about $80, and switch the pump over to 2" pipe. I could replace the 3 way, and have the two incoming 1.5" lines go out in a single 2" from the 3 way to the pump. BUT there are still a 1.5" retriction at the DE filter's multiport valve. And even if I use 1.5" male thread to 2" PVC adapters, and were to replace the slip nuts on my SWG cell housing, eventually that return line will be a restriction, even if I bury the 2" to 1.5" transition 10-15 feet away.

So my question is - is there any point in trying to change any of the plumbing to 2" while I am moving things and putting the heater in? Or should I just put a 1.5" to 2" PVC adapter before and after the heater?

A second question I just thought of - how hot is the water coming out of a pool heater? I know PVC is only rate to 140F, but surely pool heater output is much lower, as I sure don't think you want folks getting scalded at the return jets?

Thanks!
 
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Just bush the 1.5” pipe up to 2 for the heater inlet and outlets, you should be fine. The heater is designed so that the water temps will work with schedule 40 pvc. Memory serves the high limit switch would open and shut the heater down if water temps through the heat exchanger exceed 135 degrees….You don’t need to worry about anyone being scalded.
 
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Ok, I found the 2" unions for my SWG, and needed to order a new 3 way diverter valve and check valve anyway to plumb the heater properly. I need a bypass for when I run the pump in winter, but don't want to run water through the drained heater core. So I'm just gonna go with 2" where I can, to get better flow around the pump and heater, even if there is a pressure build up where the return drops to 1.5" under the concrete.

Thanks for the various bits of advice.
 
I'm back to discuss this project again. I've dug a number of trenches to pull up old pipe and conduit, and disconnected the pump, SWG and filter and moved them off the old pad, and am preparing to extend the pipes to the new location prior to pouring a new pad for everything. The old pipes are sticking up out of the ground, with nothing connected to them at the moment. Water is presumably drained down in them to the pool surface level.

It dawned on me at some point this morning that if I cut the existing pipes, almost 2 feet deep in a hole at the moment, which I intend to turn into a trench to the new location 10 feet away, that water will start draining of them and fill up my hole before I can glue joints and new PVC onto them!

With that in mind, I dug around in the shed and found some stuff I used to use when winterizing the pool, and I plugged the skimmer inlet, and I plugged the two eyeball returns. What I *cannot* do is plug the main drain that is under 8 feet of water.

So right now, I think with the return line, with the two eyeballs plugged, and the skimmer supply line, at most I will see the water drain out of those pipes, and eventually soak into the ground. However, I am now worried about the line to the main drain.

Will that line to the drain spew water if it I cut it at a level lower than the water level in the pool? If so, what do I do?

I've now disconnected everything, so its not like I can drain the pool easily. And I really prefer not to, since it is still under a safety cover, aside from the two corners I flipped up briefly to get to the returns.

One thought I had was just to just NOT bury the new 2" pipes to the new location (10 feet max) a full 2 feet down below the dirt, but maybe 1 foot down, and use a 90 degree elbow onto the existing vertical portion of the old pipes. That way I make the cuts on the old pipes above the water level in the pool. I was going to dig under them and cut off the existing 90 degree elbows to the verticals, and put a 45 degree elbow pointing horizontally to the new location, but if it means water pouring out until the pool drops 1 foot or two, I don't want to do that...

Thoughts?

Thanks!
 
jfmorris said:
So right now, I think with the return line, with the two eyeballs plugged, and the skimmer supply line, at most I will see the water drain out of those pipes, and eventually soak into the ground.
Click to expand...
Yes correct

jfmorris said:
Will that line to the drain spew water if it I cut it at a level lower than the water level in the pool? If so, what do I do?
Click to expand...
Yes the line will leak water until the level of the pool water and the level of the line are equalized. You have 2 options:
1. Drain the pool lower than the level you are going to cut the main drain line (this can be done with submersible pump)
2. Follow your plan of not burying the lines as deep as you initially thought.

jfmorris said:
One thought I had was just to just NOT bury the new 2" pipes to the new location (10 feet max) a full 2 feet down below the dirt, but maybe 1 foot down, and use a 90 degree elbow onto the existing vertical portion of the old pipes. That way I make the cuts on the old pipes above the water level in the pool. I was going to dig under them and cut off the existing 90 degree elbows to the verticals, and put a 45 degree elbow pointing horizontally to the new location, but if it means water pouring out until the pool drops 1 foot or two, I don't want to do that...
Click to expand...
 
Lake Placid said:
Yes correct


Yes the line will leak water until the level of the pool water and the level of the line are equalized. You have 2 options:
1. Drain the pool lower than the level you are going to cut the main drain line (this can be done with submersible pump)
2. Follow your plan of not burying the lines as deep as you initially thought.
Click to expand...

Ok, so if I just cut the lines above the current elbows, and then transition in the direction I need with a second elbow, am I causing flow issues with 2 elbows versus 1 elbow to get the pipes to where I need them? Or is it all a wash if I space the elbows far enough apart. I am thinking right now I would cut the pipes down to just above where I see water in them probably a foot above the current elbows, then put a new 90 degree pointing towards the new location...
 
Can you post some pictures of what we are dealing with?
You may have some state and local codes that require an 18" bury depth.
Why can you not plug the main drain?
 
PoolStored said:
Can you post some pictures of what we are dealing with?
You may have some state and local codes that require an 18" bury depth.
Why can you not plug the main drain?
Click to expand...

I can't plug the main drain as it is under 8.5 feet of water... I guess it is technically possible to swim down there and put some plastic over the drain opening, and weight it down, so that when the pipe is cut, the plastic sucks down against it. I don't think my net/brush skills are sufficient to put something in place without being under the 65 degree water...

The frost line is not much of a thing here in Alabama. And I've been through the city code, where they defer to the International pool code, 2018 edition, which I skimmed through, and it says little about the pipe depths.

Can't get a picture at the moment. The existing plumbing to the pool from the old filter/pump pad is buried about 24 inches, but at staggered depths as the pipes cross each other underground, going in different directions. However, the DRAIN line from the multiport valve to the sewer starts about 18 inches down, but within 10 feet is only 6-8 inches underground. I had to follow it to find the end next to the house, where it busts through the foundation, goes across the crawlspace, and busts out the foundation at the front of the house, where it dumps into what I think was originally a sewer line cleanout location, using an air gap. I will be covering that pipe with cement, with it coming up from an elbow 6 inches from a brick wall. This will also help with some water intrusion that has occurred over the years where they knocked a hole for that pipe and then buried it.

I think I will be ok with the plan to put the new pipes a little shallower than the old ones. It's a 10 foot run at the end of the house where no traffic ever goes, aside from me or the HVAC service technician. I also tend to keep the pipes running during winter when the outdoor temps are 32F and below, using the freeze protect feature on the Hayward pump. I'll be sure however to drain and bypass the heater during winter.
 

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Any idea what the grade difference is between pool water level and your desired pipe depth? You may find you only need to drain a foot of water or so to reach the pipe depth you were originally looking for....
 
Lake Placid said:
Any idea what the grade difference is between pool water level and your desired pipe depth? You may find you only need to drain a foot of water or so to reach the pipe depth you were originally looking for....
Click to expand...

Good question. I'll figure out the depth of the pipes in relation to the pool deck, and compare that to the water level below pool deck. My suspicion is that they are at the depth of the return lines.

For today I refocused my effort on laying out all the equipment, and worked out that I need a 3' x 8' pad poured against the end of the house, and I just got back with all the plumbing parts along with bags of gravel and quickcrete. I'm going to dig down a little so I can cut and bring that drain that goes through the crawlspace up, as it will be located inside the pad footprint, then get the pad poured. I'll trench and lay the other pipes up to the edge of the pad after that.
 
jfmorris said:
Good question. I'll figure out the depth of the pipes in relation to the pool deck, and compare that to the water level below pool deck. My suspicion is that they are at the depth of the return lines.
Click to expand...
If you can setup a line level between the water surface and the area your exposed pipes are in, you can measure down at one end to the water surface and note the measurement. At the other end measure down to your exposed pipe and note the measurement. The shorter measurement is the higher elevation and you can achieve a pretty exact difference in change in elevation (and how much you may need to drain the pool to get the water level below your desired pipe depth if at all).
 
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