The gauge is Robinair RAVG-1. It has a 1/8 inch male NPT threads and I have a 1/4 inch adapter that fits nicely into the port under the pump filter basket. Thank you again.The drain plug threads are 1/4" NPT. Can the gauge screw into the drain plug?
What is the gauge model number?
Note: Don't overstress the drain plug threaded hole as it might crack the port.
I figured out something new today. My underground plumbing is all 1.5”. The above ground plumbing is 2”. I assume that is why my flow is so low?Assuming the numbers are accurate, the suction seems to have a problem. The head loss on the suction seems to be about equal to what you would get with 100 feet of 1.5” pvc pipe, which is way too small for the suction of the pump.
What is the actual plumbing size and length of the suction plumbing?
Are you pulling from 1 or two skimmers?
Are you pulling from the main drains at the same time?
You might have a clog in the suction plumbing or baskets or maybe a clog in the impeller.
You might need to get a vacuum gauge to check the suction pressure. You can screw it into the drain plug port of the pump. It’s 1/4” NPT thread. Just don’t over tighten the gauge or it will crack the drain plug hole.
What is the actual model number (part number) from the front barcode sticker on the pump?
The silver sticker should have a barcode, a date and a P/N (part number).
Thank you. I still have not gotten suction pressure because I am getting my gauge repaired. The pipes on the suction side are 45 feet. (That is the distance from the skimmer to the pump).How many 1.5" pvc pipes are feeding the pump on the suction side?
How long are the pipes?
Did you get a suction vacuum pressure?
I am going to see if I can look for clogs in the lines today. Do you know what the threaded pipe is for at the bottom of my skimmer? Or the semicircular pvc with the hash marks on it? Thanks again for your help.I think that the pipes are undersized and they might be partially clogged.
You probably need to keep the flow rate down as much as possible and maybe have the lines checked for blockages.
Hello James, I cleaned up some of the plumbing and I got rid of the check valve as you suggested. I also was able to measure vacuum. The new numbers (without the solar are:The available information is indicating that the suction side has excessive restriction.
I would get rid of the check valve. I don't see any reason to have it there and it might be clogged with debris.
Does the pump get really loud at full speed like it's cavitating?
You can put a Jandy check valve between the pump and filter if you want, which I would recommend if you switch to a DE filter.
Remove the check valve and recheck the readings for flow to see if there is any improvement.
Extremely helpful. The solar needs 28 gpm. A few questions/observations:If you check the total head at the speed curve, the numbers don't exactly match up.
For example, at 3,450 rpm, the total head is measured at about 69 feet. The flow at 69 feet of head should be about 120 gpm at 3,450 rpm.
The measured flow is 62 gpm, which is significantly less than expected. For 62 gpm, the head loss from the curve is about 91 feet vs. the measured head loss at 69 feet.
For 3,110 rpm, you're getting 67 feet and 60 gpm. 67 feet would be about 75 gpm.
60 gpm would be about 73 feet of head.
For 2,350 rpm, you're getting 40 feet and 40 gpm. For 40 feet of head, the flow would be about 55 gpm. For 40 gpm, the head loss would be about 42 feet.
At lower speed, the numbers are not too far off.
At full speed, the pump is possibly cavitating.
Definitely keep the flow below 40 gpm unless you get the plumbing improved.
How much flow does the solar need?
The pool suction has too much restriction.
Based on the numbers, it really doesn't efficiently support more than about 38 gpm.
The power required to move water through the system increases exponentially by a cube factor.
For example, doubling the speed increases the power usage by 8 times.
So, it's always more efficient to move the water as slowly as possible.
It's hard to evaluate the pump when the plumbing is undersized.
I suspect that the pump is probably ok and most of the issue is with the suction plumbing.