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3' UNISEAL Flexible Tank Adapter (Bulkhead) - 2 Pack

Free shipping on orders over $29.99

$11.99

$ 5 .99 $5.99

In Stock

About this item

  • Versatile Attachment Solution: Uniseals provide a reliable method to attach 3 inch bulkhead fitting pipes to various containers, especially on curved surfaces like storage drums and buckets, where traditional bulkhead fittings might fail. Ideal for 3 inch Schedule 40 PVC pipes.
  • Solves Issues: Made from long-lasting TPE melt-processable rubber, this seal resists acids, oils, greases, gasoline, and sewage, while withstanding pressure up to 65 psi and extreme temperatures. Designed for 3" ID x 3.5" OD pipes with a 4" hole size, it ensures easy installation and reduced labor costs.
  • Liquid Tight Seal: UNISEAL is the world's best product. UNISEALS provide more versatility than a traditional bulkhead, handling irregularities and curvatures with ease.
  • Easy To Install: Longevity, easy installation, and reduced labor and material costs. It is made to withstand pressure and suction as well as oils, greases, sewage, waste, heat and cold.
  • The Best: To achieve optimal results in straight or curved applications, the UNISEAL is the only choice to meet your sealing needs. Made in the USA.


Uniseal is simply the world's best seal and installing the Uniseal is a simple process. After cutting a hole in the wall of a tank or other surface, the seal is inserted. Then the pipe is coated with a slippery detergent (i.e. dish soap) and pushed into the seal. Uniseal products replace traditional plumbing hardware with a single injection molded unit requiring no component parts. It was designed to solve many of the issues of pipe to tank connections. For many industries pipe to tank seals are traditionally among the most complex connections to manufacture. Traditional seals require multiple parts such as, rigid flanges, bolts, washers, o-rings, along with long assembly times and high production costs. The Du Pont Alcryn is the key to the liquid-tight seal. When the pipe is pushed through the rubber-like Uniseal from the outside, the inside Alcryn wall becomes thin enough to allow the pipe to squeeze through and then forms a liquid-tight seal. The coefficient of friction with the plastic pipe is roughly three times higher than any other material which allows it to create a better seal than with any other material. In static conditions the seal is good up to 65 PSI. Uniseal can withstand pressure, and suction, acids, oils, greases, gasoline, sewage, waste, heat and cold. It offers long life, easy installation and reduced labor and material costs.


Steve G.
Reviewed in the United States on February 5, 2025
i'm so glad i found these. instead of using rigid bulkhead fittings in my hydrosystem i used these for drain and fresh return. saved a ton of money with these plus the rubber fittings can flex some without leaking. pvc glue holding a bulkhead would break if bumped because it doesnt flex. great product no leaks
T G
Reviewed in Canada on February 21, 2022
good bulkhead seals. working great.
Jimmerz
Reviewed in the United States on July 4, 2021
Super hard to get the pipe in
Deborah Ward
Reviewed in the United States on March 14, 2021
I like these products for hydroponics. Be very careful to measure the outside diameter of hole saw. I first used a Lenox 4" saw. The seal leaked. Measured saw it was 4 1/8". Went to another on the shelf and it was exactly 4" no leaks. Good product.
paul padial
Reviewed in the United States on January 3, 2021
Holy smokes it was hard putting the pvc through it, but once you get it in, it is really water tight. Used it on a blue barrel settlement tank that moves 3000gl every hour. Not a bit of leaking. Great purchase and product.
R. Jimerson
Reviewed in the United States on February 25, 2020
Seems to work fine now but a serious pain to install.Used this on 3 inch schedule 40 pvc inlet pipe on a rainwater storage tank. Used the specified 4 inch hole saw, debured the opening and all that.The gasket was hard to slide over the (soap water lubricated) pipe off the tank. With the gasket installed in the tank there was no way to get the pipe inserted. Just no way.After seriously beveling and tapering the end of the pipe, beveling the inner edge of the hole in the tank a bit, soaking the gasket in hot water for a while to soften it up, using Vasaline and soapy water to lubricate things, two of us were finally able to horse the pipe into the tank.No instructions provided. Thank goodness for YouTube for ideas of how to make it possible.
Melinda M.
Reviewed in the United States on November 8, 2020
I wish I'd known about uniseals years ago. The plumbing into diy bio filters was so much easier! They are a tight fit, but that makes for a good seal. Absolutely no leakage. I did file a bevel on ends of pvc and abs and used some dawn dish soap to help push pipes through the uniseal. i also found putting the seal in warm to hot water first helped a lot.
aTypicalEngineer808
Reviewed in the United States on November 15, 2020
Summary: Using these 3-inch uniseal for an extra large rain barrel over flow. These are perfect in this application, instead of installing a bulkhead connector, which is more expensive, and much heavier.Pros: Good fit & finish; rubber is pliable but firm.Cons: None.Conclusion: At $12 for 2, rating these 5-stars.
IMR
Reviewed in the United States on February 12, 2019
Easy to use and fits perfectly!