What Is a Spider Gasket?

Written by Michael Dean
March 4, 2024

spider gasket

Whether you’ve come across the spider gasket while cleaning your sand or DE filter or encountered an issue with leaking in your filtration system that needs fixing, you need to get to know the spider gasket. While the spider gasket is not the most complicated piece of your pool filtration system, it is an important part that helps keep your filter running smoothly.

In this article, I will go over what spider gaskets are and what they do before diving into the specifics of common issues and fixes for spider gaskets.


Main Takeaways

  • A spider gasket is the seal on the multiport valve, so it protects the water while going in a particular direction, depending on what mode it is on.
  • The main issue you may come across with a spider gasket is water leakage.
  • To replace your spider gasket, you should remove the old one, clean and scrape off old glue, add more glue, and firmly place the new gasket to the multiport valve.

What Is a Spider Gasket and What Is Its Purpose?

When maintaining both sand and DE filters’ functionalities, the pool’s multiport valve takes control of this.

The multiport valve controls the water movement, usually with operations like normal filter mode, cleaning, backwash, winterize mode, and others. You control this by operating the pinwheel diverter, which allows you to determine the water’s direction. This is where the spider gasket comes into play.

The spider gasket acts as a seal on the multiport valve, protecting the water during transport to whichever direction it should be traveling.

Here’s what it looks like. You can pick up a replacement spider gasket at any pool supply store (I found this one at Leslie’s in my town).

In a way, we can liken the spider gasket to the gutter guards or bumpers you have when bowling with the family on a Sunday afternoon. When you use the gutter guards, you ensure that your bowling ball stays on course in the direction you want it to travel down, which is what the spider gasket does, too!

Common Issues With Spider Gaskets

As you can see, a spider gasket is an important part of your pool system. However, some problems occur with spider gaskets, which can affect their effectiveness. Here are some common problems you may experience with your spider gasket.

Worn Down or Damaged Spider Gasket

The purpose of a spider gasket is to seal between the base and the multiport valve’s pinwheel, reducing the potential risk of leakage. However, they can sometimes become damaged, usually through poor maintenance or extensive use over time.

If your gasket is broken or worn down, your best bet is to replace it. Luckily, they are super cheap!

Spider Gasket May Be Leaking

As the spider gasket acts as a seal, the main issue you may find is water leakage. This usually occurs when your spider gasket becomes enlarged or loose. The spider gasket can swell or loosen over time with use. If it is loose, you can tighten or reglue the gasket; if it is swollen, you may need to replace it. You can diagnose leakage if the water is not released to the correct destination when operating the pinwheel diverter.

If you are experiencing issues with your multiport valve, chances are that the spider valve is the issue. While you won’t have to replace them frequently, they will wear out and need repairing or replacing over time.

How Do I Maintain My Spider Gasket?

Your spider gasket is not a high-maintenance part of your pool, so I don’t blame you if it isn’t a pool part that is at the top of your mind. That said, there are some things you can do to prolong the lifespan of your spider gasket.

Clean and Inspect Your Spider Gasket a Few Times Per Year

You should check your spider gasket regularly and clean it if you notice it is dirty or has calcium buildup. You will likely only need to clean your gasket once or twice a year.

Reglue the Spider Gasket to the Multiport Valve If Needed

If your spider gasket becomes loose or separates from your multiport valve, you should reglue it to get it securely in place. You can just use super glue for this. Remember to use the glue sparingly!

How to Replace a Spider Gasket on a Multiport Valve

When it comes to the spider gasket, any crack or seam within the filtration system will allow water to leak, which will be a huge issue with the operation of your pool. When your spider gasket wears out or breaks, you’ll likely need to replace it. In this section, I will take you through each step of replacing your spider gasket.

Supplies Checklist

  • Phillips screwdriver
  • Flathead screwdriver
  • New spider gasket
  • Needle nose pliers or an adjustable wrench
  • Rag
  • Loctite glue or super glue

Step One: Turn Off Your Pump

First, ensure that you have turned off all power to your pump. You may also want to use an air release valve to relieve any pressure within the tank before removing the lid.

Step Two: Remove the Nuts and Bolts From the Valve Cover

Using a Phillips screwdriver and a wrench, remove the nuts and bolts from the multiport valve cover. I recommend you have a cup or a safe place to place the nuts and bolts so you do not misplace them.

Step Three: Remove the Cover and Spider Gasket

You should now remove the multiport cover, exposing the spider gasket. Generally, the spider gasket is secured by lube or glue. But if it is leaking, parts of the gasket will likely be loose. You may use your hands or needle-nose pliers to remove the gasket from the port.

Step Four: Clean the Gasket Area

Clean the areas inside the valve to remove any unwanted dirt or debris. Use a flathead screwdriver to remove the excess glue and debris in the grooves (where the gasket is placed), and dry the area with a rag.

Step Five: Add More Glue to the Grooves

Add glue to the grooves of the multiport valve. Take care not to add too much, just enough to seal the new spider gasket to stick into place.

Step Six: Place the New Spider Gasket

Place a bit of glue directly on the spider gasket and place the new spider gasket firmly into place. Remember, the ridged side of the gasket faces up, and the smooth side of the gasket should have glue on it, facing down. Match the outline of the spider gasket with the multiport valve to ensure it is placed correctly. Press down slightly on the gasket after placing it to ensure it is sealed and glued down.

Step Seven: Give the Spider Gasket Some Time to Set

Allow the gasket to set and the glue to dry. Generally, you’ll only need 10 to 15 minutes for this, as super glue dries very fast.

Step Eight: Reassemble the Multiport Valve

You may now reassemble the valve, secure the facial cover correctly using the indexation tabs to guide you to the correct placement for the cover, and then secure the nuts and bolts back into place using a Philips screwdriver.

Also, remember to always turn off the pump before changing valve positions. Otherwise, you may break something or even injure yourself!

Need Some Maintenance Help?

Send me a message! I can answer any of your pool maintenance, equipment, or other questions.

How to Tell Your Spider Gasket Needs to Be Replaced

Determining if your spider gasket needs to be replaced is easy. Simply take off the multiport cover and check the rubber gasket. If parts of the gasket are loose, if the gasket is no longer glued down, or if it looks overly dirty and worn down, you should replace it. If you notice water leaking from your filter through the backwash line, this is also a sign that your spider valve needs to be replaced.

How Long Do Spider Gaskets Last?

There is no hard and fast rule for how long you can expect a spider gasket to last, as many factors affect their lifespan. That said, they will generally stick around for 5 to 10 years before they need to be replaced. If you maintain your pool well, your gasket may last even longer, but you’ll likely need to at least reglue it to the multiport valve.

Spider Gaskets Keep the Water Flowing!

An often overlooked but important part of your pool filtration system is the spider gaskets. These small gaskets seal your multiport valve and help to divert the water to the intended places.

Do you have more questions about how your spider gasket works or how to replace it? Feel free to reach out to me! I am always happy to help.

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