Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: Too much pressure blowing DE grids

  1. Back To Top    #1
    wbrewski's Avatar
    Join Date
    Apr 2016
    Location
    Santa Ana
    Posts
    28

    Too much pressure blowing DE grids

    Pool store says my pump is putting out too much pressure. I have blown 3 grids i am running 18 lb on my gage ( pentair whisperflo 1.5 hp.) ( hayward DE 60 Pro filter) Has anyone had this problem and how to correct it? Should restrict the flow?
    Walt Lukowski
    Southern California
    Salt water pool at 24000 gal. new whisperflo variable speed pump. 60 gal. per min.

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    33,853

    Re: Too much pressure blowing DE grids

    Pool equipment, like filters are designed for 50 psi. So there is no reason they would "blow". In reality, the water flows from outside to inside, so they would get crushed.

    Pictures of the damage?
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  3. Back To Top    #3

    In the Industry

    Join Date
    Jan 2012
    Posts
    340

    Re: Too much pressure blowing DE grids

    How old are the grids? They are not made of anything special and wear and tear/chlorine breaks them down.
    25K aggregate IG, Intellipro, FNS48, Polaris 360, PG2000 fiber optic light source

  4. Back To Top    #4
    wbrewski's Avatar
    Join Date
    Apr 2016
    Location
    Santa Ana
    Posts
    28

    Re: Too much pressure blowing DE grids

    Quote Originally Posted by wbrewski View Post
    Pool store says my pump is putting out too much pressure. I have blown 3 grids i am running 18 lb on my gage ( pentair whisperflo 1.5 hp.) ( hayward DE 60 Pro filter) Has anyone had this problem and how to correct it? Should restrict the flow?
    I will take a couple of pictures and post them.

    Hole 2 Photo by wbrewski1 | Photobucket
    Walt Lukowski
    Southern California
    Salt water pool at 24000 gal. new whisperflo variable speed pump. 60 gal. per min.

  5. Back To Top    #5
    chiefwej's Avatar
    Join Date
    Jun 2011
    Location
    Tucson
    Posts
    2,266

    Re: Too much pressure blowing DE grids

    I have exactly the same filter and until I added a VS pump, my system ran for ten years at a filter pressure of around 30psi. The filter is rated for 50psi.
    chiefwej
    Tucson, AZ
    19k gallon Pebble Tec play pool/spa, Pentair Intelliflo VS (3 hp) 011018, Super II 2hp (for spa), Aqua Rite T-15 SWG, Pro Grid 60 DE filter, Hayward H400 & Heliocol Solar heating, A&A infloor system, fill water w/high CH and TA, 50 ppm borates,TF-100 test kit

  6. Back To Top    #6
    wbrewski's Avatar
    Join Date
    Apr 2016
    Location
    Santa Ana
    Posts
    28

    Re: Too much pressure blowing DE grids

    I have added a photo.
    and thanks for the help, I guess the pool store employee does not new his stuff
    Walt Lukowski
    Southern California
    Salt water pool at 24000 gal. new whisperflo variable speed pump. 60 gal. per min.

  7. Back To Top    #7

    Re: Too much pressure blowing DE grids

    Even though the Maximum Working Pressure is listed as 50 psi, it’s not a good idea to run anywhere near that pressure. System components are more likely to leak or fail prematurely.

    Also, 50 psi does not tell the whole story. What matters to the integrity of the grids is the pressure differential between the input to the filter and the output of the filter. For example, if a system were 70 feet below a pool, it would add 30 psi to the system, but it would not add any stress to the grids, because the pressure on both sides of the fabric is increased by 30 psi.

    In other words, it matters if the pressure is created by the grids or by something after the filter.

    At about a sustained 30 psi differential, the grids will begin to collapse and you will get tears at the spot you show because that spot does not have good support.

    The Whisperflo is a high head pump and can get up to almost 39 psi. It can definitely damage grids if the pressure is caused by dirty grids.
    It would be better to reduce the power of the pump, if possible/practical. If not practical, then keeping the grids very clean would help reduce damage.

  8. Back To Top    #8
    chiefwej's Avatar
    Join Date
    Jun 2011
    Location
    Tucson
    Posts
    2,266

    Re: Too much pressure blowing DE grids

    Instead of blowing holes in the cover material, I would have expected it to first crush the internal structure of the grid. But James is right in that pressure differential due to dirty grids, not just high pressure alone is what would cause damage to the grids.
    chiefwej
    Tucson, AZ
    19k gallon Pebble Tec play pool/spa, Pentair Intelliflo VS (3 hp) 011018, Super II 2hp (for spa), Aqua Rite T-15 SWG, Pro Grid 60 DE filter, Hayward H400 & Heliocol Solar heating, A&A infloor system, fill water w/high CH and TA, 50 ppm borates,TF-100 test kit

  9. Back To Top    #9
    wbrewski's Avatar
    Join Date
    Apr 2016
    Location
    Santa Ana
    Posts
    28

    Re: Too much pressure blowing DE grids

    Thanks for all the feedback. I will watch the pressure more closely, and backwash more often.
    Walt Lukowski
    Southern California
    Salt water pool at 24000 gal. new whisperflo variable speed pump. 60 gal. per min.

  10. Back To Top    #10
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    33,853

    Re: Too much pressure blowing DE grids

    We recommend backwashing when the pressure rises 20-25% over the clean pressure. And you should do a full tear down and cleaning at least once a year.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •