Watts 411 6 Lead-Free Check Valve, Cast Iron, Flanged

The Watts 411 6 is a 6" lead-free swing check valve with Flanged connections. It permits flow in one direction and closes against reverse flow. It features a cast iron body. Rated to 200 psi and up to 180°F. This model is certified lead-free for potable-water installations.

This 6 inch cast iron swing check valve is designed for commercial and municipal water systems, providing reliable protection against reverse flow. It features a durable cast iron body with flanged connections and a full-port design for minimal pressure drop. The valve includes a lead-free bronze disc and seat for enhanced corrosion resistance and long service life. Compliant with AWWA C508 and NSF 61 standards, it ensures dependable performance in potable water applications.

Features

• Cast iron body
• Lead free bronze disc and seat
• Flanged connections
• Compliant to AWWA C508 and NSF 61

Common Questions

Can I install it vertically?

No. The 411 6 is a swing check — the disc closes under its own weight, so it needs a horizontal run with the bonnet up. For a vertical riser, use a spring-loaded silent check instead.

Will it slam or cause water hammer?

It can. A swing check closes on the reverse flow itself, so on a pump discharge or any line with fast stops it may slam. Where that matters, choose a spring-loaded silent check or a dual-disc wafer check.

Does it come with a strainer?

No. This is an inline check valve only. If the line carries debris, install a strainer upstream — grit on the seat is the usual cause of a check valve weeping by.

Is it potable rated?

Yes. The 411 6 is certified lead-free for potable-water piping and is listed to NSF/ANSI 61 for drinking-water contact.

Specifications

• Type: Check
• Size: 6"
• Connection: Flanged
• Body Material: Cast Iron
• Max Pressure (psi): 200
• Application: Domestic Water
• Pack Quantity: 9
• Country of Origin: China
• Warranty: 1 Year Limited
• MPN: 411 6
• Temperature: up to 180°F
• Certifications: NSF-61, AWWA-C508
• Lead-Free: Yes
• Check Mechanism: Swing
• Installation Orientation: Horizontal
• Silent / Non-Slam: No
• Disc / Flapper Material: Lead-Free Bronze
• Integral Strainer Included: No