Badly mangled Pentair check valve flapper

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#1
My pool is barely 2 years old. It uses mostly Sta-Rite/Pentair equipments. A few days ago, I asked PB to come investigate what looked like a warped seal around a Pentair check valve flapper. PB came and confirmed the flapper did not look right and told me he would be coming back with a replacement cover/flapper. I've attached picture #1 here -> https://www.flickr.com/photos/49069808@N04/16063380102/in/set-72157647501207803 showing how it looked like inside the valve before it got replaced.

PB came today with a replacement part and removed the bad flapper. The bad flapper appears to have been attacked or damaged by either extreme concentration of chlorine from the Rainbow Chlorinator or hot water coming out of the heater. I've attached pictures #2 -> https://www.flickr.com/photos/49069808@N04/15878308927/in/set-72157647501207803 and #3 -> https://www.flickr.com/photos/49069808@N04/15877997119/in/set-72157647501207803 to show the warped flapper outside of it's check valve housing. As you can see from these pictures the spring would normally be silver since they are stainless steel, but the color now is yellow almost rusty. You can also see rust color stains around the clear plastic cover and the flapper itself. PB said he will send this bad flapper to the manufacturer for further investigation. I believe the PB chose to install this check valve in it's location in order to protect the heater from chlorine seepage from the Chlorinator (I've attached picture #4 -> https://www.flickr.com/photos/49069808@N04/15866624577/ to show it's proximity to both Chlorinator and Heater) .

(Please note I stopped using chlorine tabs and completely converted to BBB. Now using Liquid Chlorine since August of this year ~5 months)

Questions are:
1) What could have mangled the flapper?
2) Could strong concentrations of Chlorine from the rainbow chlorinator back flowed and attacked the flapper?
3) Since the check valve is in close proximity to the heater, would the hot water (max setting used was 84 deg f) from the heater melted it?
4) Since check valve's ability to stop water from back washing has been compromised, would you think the strong concentrations of chlorine
from the Rainbow 320 Chlorinator has back flowed into the water heater and could have attacked the heater elements?
 

JamesW

TFP Expert
Mar 3, 2011
12,647
1
#5
The check valve is supposed to be there to protect the heater from chlorine backflow into the heater. The chlorine is probably responsible for the damage to the check valve. With a bad check valve, chlorine could have gotten into the heater and caused some damage, but it's not certain.

How long does the pump stay off each day?
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#6
The check valve is supposed to be there to protect the heater from chlorine backflow into the heater. The chlorine is probably responsible for the damage to the check valve. With a bad check valve, chlorine could have gotten into the heater and caused some damage, but it's not certain.

How long does the pump stay off each day?
About 17hrs off. (Pump runs from 7am to 2pm)
 

mas985

LifeTime Supporter
TFP Expert
May 3, 2007
12,109
1
Pleasanton, CA
sites.google.com
#7
To me it looks more like it is melted. Have you been running the heater and when you run the heater, is the flow rate (RPM) much less than maximum? Lower flow results in higher exit temperatures of the heater and if the temperature got too high, it could have melted the check valve over time.
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#8
To me it looks more like it is melted. Have you been running the heater and when you run the heater, is the flow rate (RPM) much less than maximum? Lower flow results in higher exit temperatures of the heater and if the temperature got too high, it could have melted the check valve over time.
We used the heater only once a year for 2 years now during Thanksgiving (1 day), but spend the night before thanksgiving to heat the pool (makings of a tradition).
So the heater will be on for, I think, 8-10hrs set at 84 degF; and the pump is set at 2200 rpm. Pentair suggested ~1800 rpm when heating, but I wanted to get the water heated and circulation faster.
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#10
My guess is the valve melted during that heating period for some reason. During this time what was the filter pressure at 2200 RPM?
The filter pressure is ~10 psi and the pump speed is ~2200 rpm.
It surely looks like the flapper melted so the question is how far away should the check valve be installed from the heater. Currently, it is 12" to the 90 degree elbow from the heater.
I really hope that copper did not get into the pool water if the chlorine back-flowed into the heater and dissolved some copper from the heater coil. However, I had just drained the pool 50% last 2 weeks ago to lower CYA to 50 ppm. I hope that draining also got rid of some copper if there was any.
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#12
You might ask Pentair about this because the location should be fine and it shouldn't melt like that. Could be a warranty claim.
Thanks mas985. I think my PB (hopefully) will follow through with the manufacturer and have them check my heater as well. Btw - we are just a stone throw away from each other based from your location.
 

JamesW

TFP Expert
Mar 3, 2011
12,647
1
#15
It looks like only the rubber part is damaged. If the damage was from heat, then the other parts would likely be damaged as well.

I have seen many times where rubber is damaged in a similar way when chlorine from an on-line feeder migrates through a system and saturates rubber parts. The most commonly damaged rubber that I have seen is the multiport gasket. It swells up and becomes deformed like it is in the picture.

With the pump off for an extended period of time each day, chlorine has time to migrate through the system and cause damage.
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#16
It looks like only the rubber part is damaged. If the damage was from heat, then the other parts would likely be damaged as well.

I have seen many times where rubber is damaged in a similar way when chlorine from an on-line feeder migrates through a system and saturates rubber parts. The most commonly damaged rubber that I have seen is the multiport gasket. It swells up and becomes deformed like it is in the picture.

With the pump off for an extended period of time each day, chlorine has time to migrate through the system and cause damage.
I was almost hoping the flapper's grotesque figure is caused by concentrated chlorine from the Rainbow Chlorinator only because I don't use it anymore (now using Liquid Chlorine and BBB method) and not the heater because I plan on putting a FlowVis flow meter somewhere in the pipe right after the Heater. However, i am still a bit concerned the chlorine might have back-flowed into the heater components and done damage there.

I am still waiting to hear from my PB. Hopefully he's not avoiding this issue.
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#17
I was almost hoping the flapper's grotesque figure is caused by concentrated chlorine from the Rainbow Chlorinator only because I don't use it anymore (now using Liquid Chlorine and BBB method) and not the heater because I plan on putting a FlowVis flow meter somewhere in the pipe right after the Heater. However, i am still a bit concerned the chlorine might have back-flowed into the heater components and done damage there.

I am still waiting to hear from my PB. Hopefully he's not avoiding this issue.
Looking through the myriad documents/owners manuals the PB left, I came across a flier attached to the Pentair Rainbow 320 Chlorinator manual. It was some sort of a special check valve that is specifically meant for corrosive chemicals such as chlorine. I googled this Pentair part number (R172288) and found this document on-line -> http://www.pentairpool.com/pdfs/SpringCheckValveUG.pdf . I called Pentair and talked to a couple of techs but they knew nothing about specifics of this part (wasted time on the phone).

There is also this Corrosion Resistant check valve made by Magic Plastics that is supposedly designned particularly for Pools with Chlorinators -> http://www.poolsupplyunlimited.com/...120H/58768p1?gclid=COicwvG61cICFRSGfgod0xQAbQ

(Please note that my intention not to remove this Rainbow 320 Chlorinator is to use it only once a year when on vacation for 5 - 8 days. Rest of the time will be BBB)

Questions:
1) Has anyone used these types of check valve?
2) How much GPM flow loss will this check valves introduce?
3) Should the type of Pentair check valve I already have installed and failed (see pics links on the OP above) work?
 

isabelo

Well-known member
Sep 22, 2014
65
0
San Ramon, California
#18
Hi all,

A quick follow up on what has happened with this mangled check valve issue.

Since my PB took the damaged part and supposedly sent to Pentair, I could only scrutinize the failed unit with the cell phone pictures I took. Upon closer inspection of the damaged gate picture, it was evident that there was a definite heat issue that caused the gate to fail. Where the spring comes in contact with the back of the gate, you can clearly see the impressions made in the plastic when the metal spring was overheated (see here -> https://www.flickr.com/photos/49069808@N04/15878308927/in/album-72157647501207803/ ) make sure you magnify your view. I am not sure if the flow/pressure switch in the heater that prevents it from firing if the flow rate is too low failed, preventing the switch from working properly. I wonder if the heater was operating with far too little flow and almost boiling the water. There is still the question of the the Rainbow 320 chlorinator initially damaging the check valve then caused a domino effect causing the heater to fail. I really do not know and Pentair is of no help.

Pentair vehemently does not accept there was any issue with the their Rainbow 320 In-line chlorinator nor do they accept there was anything wrong with their water heater. In the months following the discovery of the failed check valve, I've decided to replace the Pentair check valve with some other unit that is more corrosion, heat, and chemical resistant. I've since then replaced it with a "CR2 Back-Flow prevention check valve that is completely corrosion resistant.

I have also stopped using the Rainbow 320 in-line chlorinator. I have since been using Liquid Chlorine and will make sure to set the pump speed/flow rate to maintain at least 40GPM when the water heater is being used, hence, I will be installing a "FlowVis" flow meter to achieve this.

-Thanks all
 

gwbisho

New member
Oct 14, 2015
2
0
Humble, tx
#19
My son had a pool installed last summer (2014). We noticed deterioration of one of the Pentair 263042 Check-Valve flappers within a couple of months, even before he used his heater. It is hot in Houston during the summer, so the heater was only used for the first time later in the Fall (Oct-Nov timeframe). There were two check valves installed, both before and after the heater. The one after is too help ensure chlorine from the chlorinator does not back flow into the heater core. The check valve installed before the heater went out first. This flapper was replaced earlier this summer. The tech said that it was very weird, spongy and also gooey/sticky. It also had the same puffed-up white look as in your pictures (exactly the same as our picture shows). Now in October I noticed that the other Pentair check valve flapper is damaged in the same way as the first one was damaged. Fortunately, the first check-valve flapper that was replaced a few months ago still looks OK and has it's typical normal grey color. I am about to order a new flapper for the second valve, but was worried that these things may keep breaking down. It looks to be either chlorine or heat damage (except that the first valve was installed before the heater, and the heater was not used when it went bad), or possibly a bad set of flappers acquired by Pentair.