RedSea 525 Backflow / Checkvalve ?

[C2_Reef]

Anyone have any pictures or details on backflow / checkvalve installed on there Redsea return ? The 525 has a "Y" and i believe they are 25 mm pipes.

I have Random Flow Generators on both sides and have to keep them low enough not to suck air while running. However when I shut the main pump down for feeding , it allows the water level to drop significantly. Just looking to add a check valve to help out.

 

[Subsea]

I am not familiar with Random Flow Generators. Would you describe what they do?

I am very familiar with check valves. As an instrumentation technician in offshore drilling and a subsea engineer on well control blowout preventers; check valves were a serious failure point that I eliminated whenever possible.

 

[UncommonSense]

Just looking to add a check valve to help out.

Skip the check valve; even NASA cannot make them 100% reliable on systems with zero contaminants in the fluid…

The better option is drilling a strategic 1/8”-1/4” hole in each of the in-tank return plumbing runs; above or near the water line, angled so it leaks down into the tank vs. making a fountain…

This hole will slurp in air during a return pump shutdown rather quickly, breaking that return plumbing siphon!

I am not familiar with Random Flow Generators. Would you describe what they do?

These are effectively a fluid eductor with some fins in the water streams path to create turbulence…

The design is a metered orifice which fires return water out at high velocity into a trumpet shaped cone… this creates low pressure at the base of the trumpet cone behind the “high pressure” water jet… there are fluid inlets in this low pressure zone, designed to suck in display water, and mix it into the high velocity return water…

At this point, it's just an eductor, so several sizes of fins are added radially to the trumpet cone to create some random turbulence in the return nozzle’s flow!

They honestly work really well, but definitely perform best at higher return plumbing pressure (higher fluid velocity through the eductor orifice)!