Nibco T-413-B Check Valve - Bronze, Bronze Seat Disc, Threaded Ends

Only in a vertical run where the flow is moving up. The T-413-B swing check works in horizontal positions or vertical-with-upward-flow; in a down-flow vertical leg the disc will not seat properly. If you need a check in a down-flow line, a swing check is the wrong style for that leg.

Both ends are female NPT (FIPT) in Class 125, so it threads straight onto any male NPT nipple, pipe, or adapter of the matching size. Nothing else is needed for a threaded steel or brass line. On copper you will need male adapters soldered on first, or you want a solder-end check valve instead.

No. Use of the T-413-B in U.S. drinking water applications is prohibited after January 3, 2014. It is intended for non-potable service: hydronic heating, condensate, steam, compressed air, and general commercial and industrial lines. For domestic water you need a lead-free bronze check valve instead.

It is a repairable valve. The bonnet screws in, so a maintenance tech can back it out and get at the internals without cutting the valve out of the line. The bronze disc is renewable and the seat is regrindable, which is the reason this style stays in service in a plant or boiler room for decades rather than being thrown away at the first weep.

Yes, the T-413-B conforms to MSS SP-80, the standard for bronze gate, globe, angle and check valves, and carries Class 125 threaded ends. That is the pair of callouts most mechanical drawings use for a bronze swing check, so it drops into a spec written that way.

Yes, and it is the most common field mistake on these. A swing check is directional. The body is cast with a flow arrow, and the disc only seats when flow runs the way the arrow points. Installed backwards the valve either stays shut or slams. On a horizontal run, keep the bonnet up so the disc swings against gravity to close; in a vertical line the flow has to be going up.

Seven threaded sizes, 3/8 inch through 2 inch: 3/8, 1/2, 3/4, 1, 1-1/4, 1-1/2 and 2 inch. Order codes run NL73005 (3/8 in), NL73006 (1/2 in), NL73008 (3/4 in), NL7300A (1 in), NL7300B (1-1/4 in), NL7300C (1-1/2 in) and NL7300D (2 in). Above 2 inch you are into a different valve body, not a larger version of this one.

200 psi (13.8 bar) non-shock cold working pressure, and 125 psi (8.6 bar) saturated steam to 353 degrees F (178 degrees C). That steam rating is what lets it sit on low-pressure steam and condensate return as well as hydronic water lines.

Metal to metal. Body, disc and seat seal are all bronze, with a bronze disc trim package. That takes the heat and steam service a rubber or PTFE soft seat would not, but it will not give you the bubble-tight shutoff of a resilient-seated check on cold clean water. Weigh that if your application is about zero back-leakage rather than temperature.

The T-413-B is a Y-pattern swing check: the disc hangs off a hinge and swings clear of the flow path, so pressure drop is low and it will pass some debris. It needs gravity and flow direction to work, which is why it is limited to horizontal runs or vertical up-flow. A spring-loaded inline check closes against a spring instead, so it can be mounted in any position and shuts faster against water hammer, at the cost of higher head loss. Pumped risers and down-flow legs generally want the spring type; gravity-friendly horizontal mains are where the swing check earns its place.