In-line relay valves work really well in long, hose lay relay pumping operations, especially when adding a pumper into the operation. The Oasis valve made by TFT is one of the more popular in-line relay valves used today and it works really well. One of the most important things about using an in-line relay valve is ensuring that the hoselines are connected to the correct inlet/outlet and that any control valves are in the "correct" position. While the Oasis valve shown in this photo is in "full operation," think about sending the "new guy" to connect the "yellow 5-inch line" to valve and it is the first line being connected to that valve.
When it comes to FD water supply operations the newest member should know the basics and the experienced member must "trust but verify" the actions taken. The good part is that the Oasis valve is simple to use. The bad part is that the Oasis valve is simple use...simple is often a detriment to FD water supply operations. So....don't assume and always trust but verify.