What if the installation operates a certain time and the tank empty?

As the operating time of the installation takes place, the inside of the membrane is emptied and the space between the membrane and the inner wall of the tank is filled with water in the same amount as foam exits the interior of the membrane.
Where appropriate a very prolonged operation would empty the tank of foam concentrate and water-filled encounter.
By proportioning only pass water because he can not leave foam inside the tank, by exhaustion, and so until the installation will not stop ie it will be pulling water, no foam mixture.