Millipore Air Gap

An air gap is a device used to protect a water system from bacteriological contamination coming from the drain. The air gap creates a stream of water without wall contact, thus preventing bacteria from moving upwards from the drain to the water system.

The Millipore Air Gap has been designed to connect easily to the 8mm OD tubing that carries reject water from the Reverse Osmosis or Elix® modules. It also can be used to remove the reject of ultrafiltration cartridges on the Milli-Q® Biocel and Milli-Q® Synthesis systems. When installed on the reject tubing of these systems, it will provide additional protection from contamination by bacteria originating in the drain.

The Millipore Air Gap also can be connected to the overflow tubing of the 30, 60 or 100 L PE tanks designed to store pure water produced by RiOs™ or Elix® lab water systems. Normally, the RiOs™ or Elix® water systems start producing pure water when the tank water level is low, and stop producing water when the tank is full.

In the unlikely event of tank level sensor failure, there is a possibility that the water system might continue to produce pure water when the tank is full. The tanks are therefore equipped with overflow tubing designed to carry the excess water to the drain and prevent laboratory flooding. This overflow is protected by a check valve, so that under normal conditions — when the overflow is not used — no aspiration of air from the drain to the tank can take place through the overflow tubing.

However, should the check valve open due to the pressure of the water produced in excess, there is a risk that the flow of water from the tank to the drain would allow bacteria to enter the tank and contaminate the pure water stored. It is therefore good practice to place an air gap downstream of the check valve on the overflow tubing to prevent that risk.

The Millipore Air Gap can operate with water flow rates of up to 150 L/hour. It is delivered with a support that can be screwed into place vertically on a wall, or on laboratory furniture. It is important to check that the Air Gap is installed in a vertical position in order to ensure proper operation.