Watts LF777SI 1 1 In Bronze Wye Pattern Strainer, Thread, 20 Mesh Screen, Tapped Retainer Cap, Closure Plug

It's built as a lead free strainer, with a body and retainer cover of lead free cast copper silicon alloy, which is what puts it on potable water service instead of the standard bronze 777SI. The screen is stainless steel and the gasket is NBR. That lead free construction is the whole reason the LF prefix exists on this series.

The rating is 400 PSI at 210 degrees F, with a minimum of 32 degrees F. Watts also publishes 125 PSI at 353 degrees F for this body, which is the steam side of the curve. So domestic hot water and heating water are well within range; if you're on steam, size your pressure to that 125 PSI figure, not the 400.

Yes. The retainer cover comes tapped with a closure plug installed, and the blowdown tapping is 1/2 inch female threaded. Pull the plug and thread in a 1/2 inch NPT ball valve with a hose nipple, and you can blow the pocket clear under pressure instead of breaking the cap off. Leave the plug in if you plan to service it by pulling the cap.

The screen is 20 mesh stainless steel. That's a general-purpose mesh for catching pipe scale, solder beads, weld slag and grit ahead of pumps, control valves, meters and backflow preventers. It is not a filter, so it won't take out fine sediment or sand in the micron range. If the equipment downstream calls for finer straining, you're looking at a cartridge filter after the strainer, not this alone.

Flow direction matters, and so does the position of the screen pocket. A wye body traps debris in an angled leg, so on a horizontal pipe the pocket has to point down or to the side, never up, or the debris falls back into the line when you open it. Install with the flow arrow on the body facing downstream, and leave enough clearance below the retainer cap to pull the stainless screen out.

It is not Buy American Act compliant. If your contract carries a BAA or Buy America clause, this strainer won't satisfy it and you'll need to source a compliant alternative for that line item.

No coating. The epoxy coating type is listed as none, so you get the bare lead free cast copper silicon alloy body inside and out. That matters if you're specifying for an aggressive or treated water system where a coated or stainless body was called for on the drawing.

Order Watts LF777SI 1 from the LF777SI series, Watts part number 379113. The size designation after the series is the pipe size, so LF777SI 1 is the 1 inch threaded model.

The retainer cover ships tapped with the closure plug in place, so the strainer arrives sealed and ready to install. The separate plug material field reads no plug, which refers to a body drain plug rather than the cover closure, so plan on the blowdown tapping in the cap being your service point.