Summary: The Oasis Hydrant Assist Valve does not include a built-in bleeder for the discharge line from the relay pumper. If you need to remove air from that section of hose, the best practice is to use the bleeder on either the relay pumper’s discharge or the attack pumper’s intake. This approach prevents pump cavitation and ensures a smooth start to your relay operation.
Why This Question Comes Up on the Fireground
A firefighter recently asked whether there's a way to bleed off the air in the discharge line from a relay pumper feeding into the Oasis Hydrant Assist Valve. It's a good question—because trapped air in a long line can lead to cavitation or delay water delivery. But here's the deal: the Oasis is built for high-volume, low-restriction flow. It doesn’t have a bleeder on the discharge path, and for good reason.
The Real Concern: Air in the Line
When you’re boosting pressure through the Oasis from a hydrant or during a relay, any length of dry hose between the pumper and the valve can hold a decent volume of air—especially if you're dealing with 1,000 feet of 5-inch. That air’s headed straight for your intake and, if unchecked, can cause your pump to cavitate or lose prime.
Even if the Oasis did have a bleeder, it wouldn't help much with the hose leading into it. The air would still need to be cleared from that upstream section.
Best Practice: Use Bleeders at the Source or Target
If you want to be deliberate about bleeding the air before charging into the Oasis valve, here’s what experienced operators recommend:
-
Open the bleeder on the relay pumper’s discharge before sending water.
-
Or, open the bleeder on the attack pumper’s intake valve to vent air as water arrives.
This allows the system to clear itself without introducing air to the pump.
Built to Push Through the Air
In most cases, the design of the Oasis allows air to be pushed through naturally once flow begins. Its full-flow path and check valves help move water fast and smooth. Most departments find that any trapped air clears out quickly without issue. But if you’re dealing with a long hose lay or very cautious about pump performance, using the pumper’s bleeders gives you more control.
Final Tip from the Field
Don’t overthink it—but do bleed it smart. One of the easiest mistakes to make during a relay is ignoring the trapped air until it becomes a problem. Taking a few seconds to crack a valve at either end of the line can save you from chasing pressure issues down the road.
Thanks to veteran firefighter Paul Neely and Ben Lehman for sharing these insights. For more on the Oasis valve, including videos and technical specs, visit the TFT website (link in red button).
Comments