Swimming Pool Blog
by Rob Cox, June 30, 2011
How to Replace a Multiport Valve Spider Gasket
Most D.E. and Sand pool filters have a Multiport valve, so called because of it's multiple ports. These are handy valves, allowing for backwashing in a single movement, and when they were introduced in the 70's, pool owners and pool service people alike applauded.
Like every piece of pool equipment however, some maintenance is to be expected. One of the most common repairs to a Multiport valve is the replacement of the internal gasket, called the Spider Gasket. This type of gasket seals the 4 ports in a Multiport valve, keeping the water from going in directions not intended.
When the spider gasket becomes old, brittle, stretched or broken, it will begin to exhibit the following:
1. Water exiting the backwash port - when Not in the Backwash position.
2. Adding DE powder to the skimmer, and noticing it returning to the pool.
3. Poor water clarity, as some water is bypassing the filter, returning to pool.
Here's the Steps involved in Inspecting and Replacing your multiport valve spider gasket.
STEP ONE: Remove the Multiport Lid or Cover. Usually six (6) screws on the top. Use a small flathead screwdriver on the bottom to hold the nuts in place, while you use a large phillips head screwdriver to remove the stainless steel screws.
Place these aside, so they don't get lost!
STEP TWO: Lift the handle of the valve, and pull out what's called the Key Assembly. You may need to use a flathead screwdriver to pry upwards to remove the valve key assembly.
Once this is removed, inspect the rotor for cracks and damage. Also inspect the spring that is between the rotor and the lid. This stainless steel spring can become corroded and eventually break. This will usually be evident by a "floppy" handle - or no tension when you push down on the multiport valve handle.
Another small inspection should be given to the lid oring, to be sure it is intact. In this case, the lid oring is under the valve cover, in the groove.
STEP THREE: Inspect the spider gasket. If the spider gasket looks warped, bent, worn or cut - you have found the problem. Removing the spider gasket seems difficult at first. Use a small sharp flathead to dig under the gasket, being careful not to damage the edges of the grooves that the spider gasket fits into.
When you get a good portion out of the groove, grab a holda that sucker and yank it out! It takes some pulling and tugging, as the original spider gaskets are spot glued into place. If it gets stuck, use that sharp, small screwdriver to help remove it.
STEP FOUR: If you ripped out the old gasket (like I advised above), you will likely have some small bits of gasket remaining in the bottom of the grooves. Use your small, sharp flathead again, and scrape the bottom of the grooves to remove all these little bits. This is important - so that your new spider gasket will fit flush, all the way into the groove.
After cleaning the grooves, or before, remove any residual water from the grooves. You can use cotton, paper towels, even a leaf blower or a shop vac. Remove all the water from the grooves so they are almost completely dry.
STEP FIVE: Use some SuperGlue or Silicone dabs - just a dab'll do ya! Place a dab or drop of glue into each spoke or channel, and then put several more around the outside groove or channel.
Place your replacement spider gasket into the groove, ridged side up, flat side down. Push it down firmly into the grooves, so that it becomes fully seated. No need to lubricate the new spider gasket.
REASSEMBLE: Place the Key assembly back into the valve housing, making sure to install in the same orientation as when it was removed. Check that the lid o-ring is seated properly.
Reinstall the screws around the lid and your done! So easy you can do it at your desk!
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