Rola-Chem flow meters

[Brentr]

There isn't any real need for a flow meter. If you want a nice toy they can be fun for a little while. In most situations that is all a flow meter is, a nice toy. Occasionally, particularly when you have a variable speed pump, or an especially complex setup, a flow meter is important to have, but normally it doesn't make any difference.

The Blue & White 300 series flow meters are inexpensive and of reasonable quality. If you really want a flow meter you should be able to find one of them that is suitable for your setup.

Not to hijack this post, but I am wanting to install a flow meter and I came across one made by Rola-Chem, http://www.allwatermeters.com/rola-chem ... eters.html
Does anyone have any experience with this brand? These are about half the cost of the Blue and White 300 series.
Thanks in advance

If there is even the slightest possibility that you might be hijacking a post, start a new topic. Thanks JasonLion

 

[JasonLion]

From what I have heard, the Rola-Chem flow meters work alright for a while, but don't age as gracefully as the Blue and White ones. They are inexpensive and easy enough to replace, so that might not be a problem.

 

[Aquaman95]

They also don't clog as easily since they have a larger orifice. But, they are made out of a molded plastic instead of drilled acrylic block so they aren't as sturdy.

 

[Brentr]

Thanks guys for the reply, sounds to me that I should invest in the Blue and White series 300. Can you suggest who to buy them from? I have noticed that the prices are all over the board from $60 to over $100?

 

[mas985]

Just curious as to why you think that you need one? Note too that the flow meter usually needs a fairly long (28") and straight piece of solid pipe so the readout is accurate.

 

[lbridges]

I'm not Brentr, but I do know he recently put in a solar system. I too would be curious about flow (too fast, too slow, or just right - Goldilocks reference, sorry).

 

[learthur]

I have a RolaChem flowmeter on my system. Had it over 2 years now. No problems. Glad I didn't spend more money on the other brand as I considered them also.

Lee

 

[Guest]

Blue and White here. It's all we've ever used, and I can't ever recall a problem.

 

[Brentr]

Just curious as to why you think that you need one? Note too that the flow meter usually needs a fairly long (28") and straight piece of solid pipe so the readout is accurate.

mas985, lbridges is correct. I am wanting to find out my approximate flow because I would like to replace my 1 speed pump with a 2 speed pump and try to run the solar on the low speed. I do not have full automaton and was hoping that the system would prime on low speed. My vacuum break is about 10ft and I have the panels mounted on a one storey house, max feet is about 14 ft with a rise in psi for 18psi to 24psi according to the gauge on the sand filter.

 

[mas985]

If you are just looking for an approximate flow rate, I might be able to help with that.

Based upoin what you have told me so far, your flow rate is probably around 76 GPM (18 PSI) without solar and 59 GPM (24 PSI) with solar. Low speed on a two speed pump of the same size would be half those values. The running pressure will be about 1/4 of what is now. So low speed with solar will be about 30 GPM at 6 PSI.

That may or may not be enough pressure to keep the VR closed. It depends on the dynamic head loss between the filter and the VR. But that can be fixed by lowering the VR on the source pipe, ~ 6' above the pump. It should then stay closed.

As for priming, that may still be possible on low speed but it is very close. If you add 10' of head to the low speed running head, the flow rate will be about 19 GPM during priming. The theoretical purge rate for 2" pipe is about 16 GPM so there is not much in the way of margin so it could take a very long time to fully purge the panels. But there is a possibility that it could work.

BTW, if you watch the pressure guage as the panels are priming, does it go above 24 PSI? This can tell you how much head is needed during the purge process so a better estimate can be made. Also, if you tell me more about your plumbing, I can get a more accurate estimate.

 

[Brentr]

If you are just looking for an approximate flow rate, I might be able to help with that.

Based upon what you have told me so far, your flow rate is probably around 76 GPM (18 PSI) without solar and 59 GPM (24 PSI) with solar. Low speed on a two speed pump of the same size would be half those values. The running pressure will be about 1/4 of what is now. So low speed with solar will be about 30 GPM at 6 PSI.

That may or may not be enough pressure to keep the VR closed. It depends on the dynamic head loss between the filter and the VR. But that can be fixed by lowering the VR on the source pipe, ~ 6' above the pump. It should then stay closed.

As for priming, that may still be possible on low speed but it is very close. If you add 10' of head to the low speed running head, the flow rate will be about 19 GPM during priming. The theoretical purge rate for 2" pipe is about 16 GPM so there is not much in the way of margin so it could take a very long time to fully purge the panels. But there is a possibility that it could work.

BTW, if you watch the pressure gauge as the panels are priming, does it go above 24 PSI? This can tell you how much head is needed during the purge process so a better estimate can be made. Also, if you tell me more about your plumbing, I can get a more accurate estimate.

Okay mas985 here is some more info
1. I have 2inch plumbing to returns and from drain and skimmer. I have 1.5 inch going to sheer descent, IG fountain, Dolphin statue and deck jet and (pool cleaner which I very rarely use, no need to because I have a screen enclosure). I only put these on for parties and on the weekends, so I could switch to high speed when I want to use them.
2. I have the Sta – Rite Dura – Glas P2RA5F , 1.5 hp pump, SF factor 1.1, 3450 rpm, max amps 19.6/9.6, which I would like to replace the motor only to a 2 speed motor which I believe is model P2RA5YF-182L
3. I have 1.5 inch reduction to and from the pump and the sand filter Hayward Pro Series, S220T Sand Filter
4. I spoke to the aquatherm tech this am and she tells me that I would need a flow rate of 5gpm for each of my 4x12 panels, and a flow rate of 3gpm for each of my 2x12 panels. That is a total of 21gpm or greater to get the best efficiency from the panels.
5. The height of the vacuum release measures 8ft 3 inches to the floor of the pump.
6. When the solar system turns on the psi gauge starts up at 11psi and gradually moves up to 24psi staying 20- 22psi for about 3-4secs. It never went above 24psi. It took about 40 secs to purge the system but all the water may not have drained out.

Thank you for your help and comments, I think it would be great if I did not have to do any complicated wiring or plumbing, or spend money on automatication/ VF pump of which I do not have right now :-D

 

[mas985]

For the return side and suction side runs from the pool to the equipment, are they single lines or do you have multiple lines (e.g. a separate line for the skimmer and main drain or is the main drain tied in through the skimmer or teed)? Also, about how far is it from the pool to the pad?

 

[Brentr]

For the return side and suction side runs from the pool to the equipment, are they single lines or do you have multiple lines (e.g. a separate line for the skimmer and main drain or is the main drain tied in through the skimmer or teed)? Also, about how far is it from the pool to the pad?

1. The pool to pad measures approx 50ft.
2. The skimmer and drain are 2 separate 2inch pipes which go to 3 way pentair never lube valve and the 2 inch pipe of 14 inch run to the pump.
3. The average run length of the skimmer is approx 50 ft of 2 inch pipe
4. The average run length of the drain is approx 78 ft of 2 inch pipe
5. The average run length of return is approx 50 ft of 2 inch of pipe. From there I am assuming that it T's off to 1.5 inch of pipe to 3 returns, of which average lengths measure 20ft to one return, 27ft to another return and 4ft to the other return.

 

[mas985]

Thanks, that helps. Not much of a change but here is what I estimate.

No Solar (HS): 77 GPM @ 49' of head
No Solar (LS): 37 GPM @ 13' of head

Solar (HS): 63 GPM @ 63' of head
Solar (LS): 30 GPM @ 17' of head

Priming (LS): 22 GPM @ 19' of head (including 10' of panel height and all of the plumbing so a worst case)

The VR at it's current height, should remain closed through both the priming and the primed phases at low speed. However, I'm not sure that 22 GPM will push all of the air out of the return pipe but it may be possible. If it doesn't the flow rate will likely reamin at 22 GPM and you won't get to 30 GPM. The panels will still be full of water only the return pipe will have some air in it. It isn't critical that it is fully primed but it helps by removing the vertical lift from the head loss.

Now if you do go this route and the pump does not prime the panels on low speed, you could probably rig a timer to have a priming cycle. Do you have a separate controller for a solar valve or is it a manual valve?

Dual Speed Pump Timer

 

[Brentr]

mas985, I have a gl-235 controlling the solar. I also have the intermatic timer model T-104R.
See pic from left to right, GL SWG (white box), intermatic timer ( small grey box) gl-235 (small white box above the small grey box) , Electrical sub panel ( large grey box)

 

[Brentr]

Thanks, that helps. Not much of a change but here is what I estimate.

No Solar (HS): 77 GPM @ 49' of head
No Solar (LS): 37 GPM @ 13' of head

Solar (HS): 63 GPM @ 63' of head
Solar (LS): 30 GPM @ 17' of head

Priming (LS): 22 GPM @ 19' of head (including 10' of panel height and all of the plumbing so a worst case)

The VR at it's current height, should remain closed through both the priming and the primed phases at low speed. However, I'm not sure that 22 GPM will push all of the air out of the return pipe but it may be possible. If it doesn't the flow rate will likely reamin at 22 GPM and you won't get to 30 GPM. The panels will still be full of water only the return pipe will have some air in it. It isn't critical that it is fully primed but it helps by removing the vertical lift from the head loss.

Now if you do go this route and the pump does not prime the panels on low speed, you could probably rig a timer to have a priming cycle. Do you have a separate controller for a solar valve or is it a manual valve?

Dual Speed Pump Timer

Mark I want to thank you for your input and the time you spent helping me. Just to bring you up to date. I have decided to wait and look at my next month's electric bill. My next thought is to try to put the solar on a timer because I have noticed that the first 2 hrs of start up and the last 2 hrs there is no change in water temp, however I have noticed that as the weather gets warmer the solar runs less hrs to bring up the temp. In fact I adjusted the temp to 85 degrees on the thermostat and the pool temp when I got home was reading 92 degrees. Today the day high is 87degrees. I will be monitoring that closely this weekend as we have temps in the low to mid 80s.