Sigh Collector

Step 5 Combine electronics with main unit. Install Check Valve and Pump

Place the air pump and circuit inside of the main unit, on the lower shelf. Now it's time to make a connection between the air pump, and the air bladder/balloon, which will sit on the surface.
We only want air to go one way, and not come out the other direction, so we use something called a "check valve". The basic principle is that a hinged door, rubber diaphragm or ball is displace by air going one way, but then prevents the air from going back.

I bought my check valve on McMaster Carr's website; More specifically it's called a PVC Swing-check valve. I'm using the 1" diameter one. This one was attractive to me because of it's extremely low "cracking pressure", or the pressure needed to displace the barrier. < 0.1 psi !!

I used a simple garden hose to run from the pump, to the check valve, then from the other side of the valve into the balloon. The fittings are coupled and sized properly, and I used some glue to further secure them, and prevent any air leaks...