For new owners, this is a very common question – Why is there an air bubble in my Rainman Pressure Guage? Is it supposed to be there?
First of all, as a Rainman Watermaker owner and Seatask customer, you always have access to our expertise for any questions during the operation of your system – we are always happy to help, and may even have a fact sheet like this one to show you.
So, the air bubble – is it normal? …. Short answer… Yes, Certainly is
The air bubble in the gauge is actually intentional – and in fact, is necessary for the gauge to operate correctly.
The Oil is effectively dampening the internal pressure to ensure accurate readings -and effectively having a cushioning effect on the gauge needle.
The air bubble ensures that the oil has some slight expansion as the gauge heats and cools. The air is compressible, so can be squeezed by slightly expanding oil. Otherwise the oil would force its way out of the gauge.
Which is good news for your gauge!