Valve & Cap

What Do the Valve and Cap Do?

The component that inflates the dunnage bag and keeps it inflated is the one-way dunnage bag valve. A dunnage bag inflator or inflation gun connects to the valve to fill it with air; the one-way mechanism inside the valve stops air from escaping back out once the inflation device is disconnected. The cap fitted over the valve protects its opening from dust, moisture and impact during transport and storage.

PAKKORA's valve and cap range covers two different valve mechanisms: a quick-connect valve that attaches to an external dunnage bag inflator or inflation gun, and an integrated-cap valve (screw or flip-top) that can be inflated directly by opening its own hinged cap. Which type to use depends on compatibility with the connection fitting on the inflation equipment already in use.

What to Consider When Choosing a Valve

• Connection compatibility: The valve must be compatible with the connection fitting on the inflation device being used (quick-connect, screw, or bayonet type).
• Seal integrity: The one-way mechanism must close fully without leaking air — this is critical to holding pressure throughout transport.
• Cap integrity: A cap that stays securely in place prevents the valve from being damaged by impact during transport.

Why Is It Treated as a Separate Component?

No matter how strong the dunnage bag body (kraft or woven PP) is, the integrity of the whole system depends on the valve sealing properly. In the field, the most common failure point isn't the body tearing — it's the valve failing to close fully, or the cap getting lost during transport. For this reason, the valve and cap can also be supplied separately as spare parts, so that existing dunnage bag stock isn't taken out of service simply for lack of a valve or cap.

Maintenance and Inspection

The valve and cap should be visually inspected before inflation, and any cracked or deformed valve should not be used. A damaged valve can cause the dunnage bag to lose pressure during transport, leaving the load without proper securing.

Common Problems

• Valve that doesn't close fully: Dust or moisture getting into the valve mechanism can prevent the one-way closure from sealing completely, leading to slow air loss.
• Missing cap: If the cap is missing during storage, the valve is left unprotected against impact and contamination.
• Forcing an incompatible connection: Forcing on a compressor adapter that doesn't match the valve type can permanently damage the valve body.

Supply as a Spare Part

The valve and cap can be supplied independently of the rest of the dunnage bag. In stock that has sat in storage or is used infrequently, it's common for the cap to go missing or for the valve to stiffen and lose its flexibility; being able to source these parts separately keeps the stock usable without having to replace the entire dunnage bag.

Compatibility With Different Dunnage Bag Types

Kraft and woven PP dunnage bags may use different valve mounting methods depending on the manufacturer, so any replacement valve and cap sourced for a dunnage bag must be confirmed to match the existing product's connection size and body material. An incompatible valve may not mount to the body with a proper seal.