Y strainers (Wye-strainers) are devices for mechanically removing unwanted solids from liquid, gas or steam lines by means of a perforated or wire mesh straining element. They are used in pipelines to protect pumps, meters, control valves, steam traps, regulators and other process equipment.
Y strainers are very cost effective straining solutions in many applications. Where the amount of material to be removed from the flow is relatively small, resulting in long intervals between screen cleanings, the strainer screen is manually cleaned by shutting down the line and removing the strainer cap. For applications with heavier dirt loading, Y-Strainers can be fitted with a "blow-off" connection that permits the screen to be cleaned without removing it from the strainer body.
Y strainer has the advantage of being able to be installed in either a horizontal or vertical position. However, in both cases, the screening element or "leg" must be on the "downside" of the strainer body so the entrapped solids can be properly collected and held for disposal.