Hydrostatic Inflator Technology with Hammar®

Hydrostatic Inflator Technology with Hammar®

4 minutes
Despite its small size, the Hammar inflator is of huge importance for your lifejacket’s performance—and as trustworthy as gravity itself. The mission of the inflator is to give your lifejacket buoyancy when you need it and protection against unintentional activation when you don’t. It inflates only when you are being submerged past 10 cm (approximately 4-inches) of water in depth. However, if you fall into the water and the inflator does not reach 10 cm you can manually inflate the jacket with the pull-tab.

In Water Performance


Features of the Hammar Lifejacket Inflator

    • Protection against unintentional activation
    • Single point indicator: Red = needs replacement. Green = ready for use!
    • No service requirements for the Hammar inflator for 5 years


Equipped With a Hydrostatic Valve

The Hammar Inflators hydrostatic valve gives unique protection against inadvertent inflation in case of rain, spray, splash or humidity.

Single Point Indicator Shows the Status of Your Hammar Inflator

When the single point indicator is green the inflator is ready for use. After activation (automatic or manual) the indicator turns red and the inflator must be replaced. Always check the single point indicator before using your lifejacket.

Service / Maintenance

The Hammar automatic inflator is easy to maintain just ensure that the inflator is replaced after five years expiry date or when the single point indicator is red.

How Does the Hammar Inflator work?

The Hammar Inflator activates automatically when submerged and a pressure difference of about 10 cm (4-inches) is reached. The lifejacket will reach full buoyancy within seconds and it is designed to ensure fast and reliable activation, only when needed, even in the most extreme weather conditions. It is important that you don the lifejacket according to the manufacturer’s instructions in order to secure the function of the lifejacket and for automatic inflation. 



The automatic inflator consists of a hydrostatic valve, a water-sensitive element, a gas cylinder inside a bladder with an air bubble trapped inside. When the Hammar Inflator is exposed to sufficient pressure it will open its hydrostatic valve, allowing the water to meet the water-sensitive element and trigger the activation.

Measuring the pressure

The Hammar Inflator uses the pressure difference between the internal and the external pressure of the inflator. The external pressure is determined by the water depth of the inflator. The internal pressure is determined by the trapped air bubble in the lifejacket bladder. There is always some air left even in a well-vacuumed lifejacket bladder. When the lifejacket enters the water, the air bubble inside the bladder will move to the highest point of the bladder. If some part of the lifejacket is above the water the air bubble will move to that area, or if the whole lifejacket is submerged the air bubble will move to the highest point, closest to the surface. The pressure difference is determined by the depth of the inflator and the highest point where the trapped air bubbles have gathered. If this distance is more than 10 cm, the inflator will activate, and the lifejacket inflates.

For more information on Lifejacket Service:

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