Plumbing for my new sand filter

[MStein]

I'm replacing my old DE filter with a new sand filter and I have to redo everything because the new one is to big to fit on the pad. I'm a 3D artist so I decided to throw this image together to help me figure it out. The 3D model is measured accurately. In the corner you can see what i'm starting with.

Do you see anything wrong with what I'm going to do? All suggestions are welcome.

 

[Texas Splash]

Nice illustration. Just a few comments that caught my eye:
- Plumbing coming up through the concrete? That always makes me nervous for fufure maintenance. Perhaps have the plumbing come up just outside the pad?
- Unions! Can't say enough about having unions in places where future disassembly may be required. Just be sure to think that through.
- At some point replace that sinlge speed pump with a new variable speed. That's icing on the remodel cake.

 

[MStein]

Nice illustration. Just a few comments that caught my eye:
- Plumbing coming up through the concrete? That always makes me nervous for fufure maintenance. Perhaps have the plumbing come up just outside the pad?
- Unions! Can't say enough about having unions in places where future disassembly may be required. Just be sure to think that through.
- At some point replace that sinlge speed pump with a new variable speed. That's icing on the remodel cake.

Plumbing in the concrete has been like that for 40 yrs. Leaving that alone. I'l only replacing the PVC to copper adapter so its all good.
Where would i put unions?

2 questions.
1- The treaded adapters at the pump and valve, are they standard threads?
2- Is the distance between pump and filter a problem, as in possible small moments of that pipes causing stress on the valve?

 

[Texas Splash]

Where would i put unions?

Anywhere you might expect future maintenance like at the multiport valve as one example.

The treaded adapters at the pump and valve, are they standard threads?

Not always. Some pumps have proprietary threads which can be "slightly different than a standard Schedule 40 PVC union. Bes to shop on Amazon for a Hi-Temp pump union adapter.

Is the distance between pump and filter a problem, as in possible small moments of that pipes causing stress on the valve?

I doubt it. That line from the pump outlet to the filter should be okay. But if you felt it might be best to support it later, you could make a vertical support fairly easy if needed.

 

[1poolman1]

Plumbing in the concrete has been like that for 40 yrs. Leaving that alone. I'l only replacing the PVC to copper adapter so its all good.
Where would i put unions?

2 questions.
1- The treaded adapters at the pump and valve, are they standard threads?
2- Is the distance between pump and filter a problem, as in possible small moments of that pipes causing stress on the valve?

The threads in a Hayward MPV, if it is a 2" valve, are 2" FIP, standard pipe threads (the same goes for 1.5" valves). If you can get 2 two-inch high-temp unions to fit side-by-side in the valve that is the way to go, but I believe they will interfere with each other. I typically use a 2"X12" CPVC pipe nipple cut in half and some self-aligning pool unions like made by CMP. One can be installed in the pipe going directly into the valve and another before the last 90 so they don't interfere with each other.

 

[MStein]

The threads in a Hayward MPV, if it is a 2" valve, are 2" FIP, standard pipe threads (the same goes for 1.5" valves). If you can get 2 two-inch high-temp unions to fit side-by-side in the valve that is the way to go, but I believe they will interfere with each other. I typically use a 2"X12" CPVC pipe nipple cut in half and some self-aligning pool unions like made by CMP. One can be installed in the pipe going directly into the valve and another before the last 90 so they don't interfere with each other.

It is 2' and I noticed they were very close to each other. I ordered these from SupplyHouse I hope they fit.

 

[MStein]

The threads in a Hayward MPV, if it is a 2" valve, are 2" FIP, standard pipe threads (the same goes for 1.5" valves). If you can get 2 two-inch high-temp unions to fit side-by-side in the valve that is the way to go, but I believe they will interfere with each other. I typically use a 2"X12" CPVC pipe nipple cut in half and some self-aligning pool unions like made by CMP. One can be installed in the pipe going directly into the valve and another before the last 90 so they don't interfere with each other.

I ordered the one on the right, should i have ordered the one on the left? the other one looks a lot narrower.

 

[1poolman1]

I ordered the one on the right, should i have ordered the one on the left? the other one looks a lot narrower.

I prefer CPVC, but if you use the unions you will be able to address any leaks that may occur at the valve.

 

[MStein]

I prefer CPVC, but if you use the unions you will be able to address any leaks that may occur at the valve.

I'm confused, I'm I supposed to use a threaded male union straight into the valve? I just watched an install video where they said to use a threaded union and NOT to use a threaded male adapter. Is this true and if it is, where do I find them?

If I use a threaded adapter with thread sealant, is it going to leak?

 

[1poolman1]

I'm confused, I'm I supposed to use a threaded male union straight into the valve? I just watched an install video where they said to use a threaded union and NOT to use a threaded male adapter. Is this true and if it is, where do I find them?

If I use a threaded adapter with thread sealant, is it going to leak?

If you can get two high-temp threaded unions in that valve side-by-side, that is a great way to go. They seal with an O ring against the valve body. I still use three wraps of Teflon tape on those because I hate call-backs for a drip that might occur. In your picture the fitting on the right is CPVC. They work fine. I use a CPVC nipple as they are easier for me to obtain. Male CPVC adapter or CPVC nipple with a union at some point near the valve will work fine if you can't get 2 High-temp unions to fit.
Yes, sealant is needed (I use five or six wraps of Teflon tape AND silicone sealant over that) with the adapter and/or pipe nipple so that it won't leak. Will a leak occur at some point? Maybe. That's why unions are recommended. That way the fitting can be tightened a bit or removed and resealed if needed.
High-temp unions are threaded into the valve as far as they will go to compress the O ring. Pipe threads on an adapter or nipple should not be installed that far. They are tapered and either the valve, the fitting. or both will be damaged. Usually it is good to have no less than three threads showing when the fitting is tight.

These are an example of a high-temp union. You can see that the two nuts may not fit side-by-side in your valve.

Amazon.com

 

[ferretbone]

I agree with poolman, use those CMP unions with the shinny black nut. Not the knock off unions that have a larger flat black nut. I know the CMPs fit on the newer pentair valves side by side for sure. On a hayward multiport valve you may only be able to fit two unions. One union on the inlet/outlet and one on the back wash side. That way you would only need to cut one pvc line to remove the valve. But I believe, not know for sure, those high temp unions fit side by side on the hayward valves too. Use some high temps on your pumps suction and return side as well. Those unions, and male adapters will need at least silicone on the threads.

 

[MStein]

UPDATE

So I had to improvise a few things from my original plumming design. Everything is connected but I ran out of daylight so I'll start it up in the morning.

Feed back is always welcome. If you see something I did wrong, please tell me LOL.

 

[MStein]

If you can get two high-temp threaded unions in that valve side-by-side, that is a great way to go. They seal with an O ring against the valve body. I still use three wraps of Teflon tape on those because I hate call-backs for a drip that might occur. In your picture the fitting on the right is CPVC. They work fine. I use a CPVC nipple as they are easier for me to obtain. Male CPVC adapter or CPVC nipple with a union at some point near the valve will work fine if you can't get 2 High-temp unions to fit.
Yes, sealant is needed (I use five or six wraps of Teflon tape AND silicone sealant over that) with the adapter and/or pipe nipple so that it won't leak. Will a leak occur at some point? Maybe. That's why unions are recommended. That way the fitting can be tightened a bit or removed and resealed if needed.
High-temp unions are threaded into the valve as far as they will go to compress the O ring. Pipe threads on an adapter or nipple should not be installed that far. They are tapered and either the valve, the fitting. or both will be damaged. Usually it is good to have no less than three threads showing when the fitting is tight.

These are an example of a high-temp union. You can see that the two nuts may not fit side-by-side in your valve.

Amazon.com

I got those unions you recommended and they fit just fine side by side at the valve.

I posted pics in an update above.

Thank you very much

 

[MStein]

Well the only thing that leaked was the stupid drain plug.

 

[JBnj]

If you are looking to add high-temp unions to a 1.5" MPV here's a solution if you are looking to cut done on the number of fittings - you will see that the pump union has a slightly longer shaft which allows for the two unions to sit comfortably side-by-side without any additional fittings...........
The pump union is from Custom Molded Products #21063-154-000
The return union is from Praher #150-906
Hope this helps with a 1.5" setup!
BTW - I use no dope or tape on the union threads - the rubber gasket does all of the work