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Plastic bottle cap with venting nozzle for breather screw cap to suit poly water tanks
Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks
Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks
Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks
Plastic bottle cap with venting nozzle for breather screw cap to suit poly water tanks
Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks
Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks

Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks

by Boab
SKU FTUCAP
$25.00 - $25.00
$25.00
$25.00 - $25.00
$25.00
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Vented / Breather Screw Cap to Suit Poly Water and Diesel Tanks by Boab

This vented (breather) screw-on cap for a water or diesel tank is designed to screw onto the opening of your water or diesel storage tank. The cap has a screw thread on the inside, which is used to tighten the cap onto the tank, forming a secure seal.

The cap has a built-in vent, which allows air to enter the tank as liquid is dispensed, preventing vacuum pressure from building up and making it difficult to pour the liquid. It essentially allows the tank to breath while preventing spillage. The vented screw-on cap helps ensure that the water or diesel tank can be easily filled and emptied, while also helping to prevent spills and leaks.

Specifications: 70mm (2.8") Diameter

Frequently Asked Questions

What does the vent on this cap actually do?

The built-in vent allows air to enter the tank as liquid is dispensed. Without ventilation, a vacuum forms inside a sealed tank as fluid is drawn out, making the flow increasingly difficult and inconsistent. This cap is designed to let the tank breathe naturally during use, maintaining a steady pour while preventing liquid from escaping back through the vent.

What size tank opening does this cap fit?

This cap is 70mm (2.8") in diameter. Measure the thread opening on your tank before ordering to confirm compatibility. Poly tank openings vary between manufacturers and models, and even a small mismatch in thread size will typically prevent a proper seal.

Is this cap suitable for diesel as well as water?

Yes, the cap is designed for both poly water tanks and poly diesel tanks. Poly tanks used for diesel storage are generally made from HDPE, which is resistant to diesel fuel, and this cap is rated to suit both applications.

How does the cap attach to the tank?

The cap has a threaded interior that screws directly onto the tank opening. Turn it clockwise until snug to form a secure seal. No tools are required for fitting or removal.

What is the difference between this vented cap and a standard sealed cap?

A standard sealed cap closes the tank completely, which is fine for storage and transport but creates a vacuum inside as liquid is poured out. A vented cap has a small air passage that lets air in to replace the fluid as you dispense, keeping flow steady and eliminating the gurgling or stop-start pour you get with a non-vented cap. The vent is designed to allow air exchange without letting liquid escape during normal use.

Will this cap fit my poly jerry can or aftermarket water tank?

It depends on the thread size of your container's opening. This cap is 70mm (2.8") in diameter, which suits many common poly water and diesel tanks. Measure your existing cap or the tank opening before ordering to confirm the thread pitch and diameter match. Not all poly containers use the same thread standard, so it is worth checking before you buy.

Will this breather cap fit my Tuff Terrain 40L Footwell Tank?

Yes, we can confirm this Boab breather cap will fit a 40L Tuff Terrain footwell tank.

Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks Boab Vented/Breather Screw Cap to Suit Poly Water and Diesel Tanks

Can I use this cap on a petrol tank?

This cap is designed for water and diesel tanks, not petrol storage. Petrol has different chemical properties to diesel and may degrade certain plastic components over time. We recommend using caps specifically designed and rated for petrol applications if you are storing fuel of that type.

Is it safe to leave this cap on during transport with a full tank?

The cap is designed to screw down securely and limit spills under normal conditions. The vent allows air exchange when dispensing and is intended to assist in preventing liquid out during transport. For best results, keep the tank upright and properly secured during travel to minimise pressure on the cap from liquid movement. Inspect the cap periodically to ensure the thread seal remains in good condition.

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We know that you have a lot of options out there, and we’re incredibly grateful that you’re considering spending your hard earned money with us. We like to think we stand out from the crowd in a few ways.

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4x4 Down Under is built on honesty and integrity. For example when you make a purchase with us we only charge your account once we confirm the product is ready for dispatch. Although we like to guarantee everything on our store is available we’re not perfect and mistakes do happen. If something turns out to not be available we’ll let you know immediately and you have the option to cancel your order or wait for more stock to arrive. Should you not want to wait the order is voided, and there’s no waiting a week to get your money back (it’s instant!).

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We're Australians, and we like to support our fellow Australians, which is why all our products are sourced locally from the official Australian distributors. Nothing is imported directly and we don't stock any grey imports. This also means that all manufacturer warranties are fully honored by the brands themselves.

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If you still have any doubts feel free to give us a call on 1300 76 86 41, or contact us here. We'd love to hear from you.

Shipping Cost

A shipping calculator can be located in your Shopping Cart. Please add your item to the cart, once in your Cart page, click "Calculate Shipping" link, enter your postcode and you will be informed of the shipping cost (if any).

Order Dispatch

Orders are usually dispatched within 1-3 business days. Should there be any delays we will let you know immediately.

In order to get your purchase to you as promptly and safely as possible we utilise a number of trusted and reputable courier services, including Australia Post (depending on the item and your location). These delivery services should have your item delivered to your door within 2 - 10 working days depending on your location. In some cases where the address is based in the more regional parts of Australia this may take longer. Should the delivery time take longer than we would like we will let you know.

As soon as the item has been shipped we will provide you with a tracking number via email. You can then use this number to watch your item make it's way toward your location. It should also give you a clear idea of when to expect your item.

Depending on the item we may contact you to arrange delivery. In order to ensure your purchase lands in the correct hands we will require a signature from you on delivery. If you are not home on delivery the postman/courier will leave a card with collection details.

Please feel free to contact us should you want to make alternate arrangements for delivery. We’re flexible and here to help.

Please note that unfortunately for almost all items we're unable to ship to PO Boxes (and/or Parcel Lockers or Parcel Collect). Please rather use a street or work address, or that of a friend, colleague or family member.

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