Flushing Strainers

Simplex Basket Strainer with Flush (Back-Flush) Capability

Similar to the blowdown feature found on a Y-strainer, a flushing (back-flush) simplex basket strainer is a variation of a standard simplex basket strainer designed to quickly purge collected debris without dismantling the housing. It uses a special “bottomless” basket that allows accumulated particles to discharge through the drain port when a flush valve is opened.

Manual or Actuated Flush Valves

We can supply the flushing strainer with either a manual drain valve or an actuated valve assembly. The actual debris discharge from the basket typically takes 1–2 seconds, however with an actuated valve the overall “flush cycle” is governed by the actuator travel time—commonly 18 to 30 seconds from closed → open → closed.

Automation Considerations

While automatic flushing can be attractive, it often introduces additional control requirements. In many applications, an automated flush system will need a PLC (programmable logic controller) to:

• trigger flushing on a timer or differential pressure (DP) setpoint
• manage upset conditions, such as when debris becomes embedded and the DP does not drop sufficiently after a flush cycle

Because flushing primarily removes loose collected debris (rather than actively cleaning the screen), the added complexity and cost of automation can approach that of a true backwashing strainer system—which does clean the screen. For this reason, automated flushing is typically most practical where debris loading is very light, such as small amounts of hard particulate (e.g., pipe scale) that does not smear or embed into the screen.

Key Advantages

• Cost-effective solution for smaller strainer sizes
• Higher open area than a Y-strainer, resulting in lower pressure drop and less frequent flushing
• Fast, simple debris removal via the drain port (no disassembly for routine purging)