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Stainless steel dual check valve with vent, 3/8 inch MNPT connections

Watts

Watts 9BD Dual Check with Vent 3/8in MNPT

SKU CH-0F4C-EP81B

A dual-check valve with atmospheric vent for backflow prevention in plumbing systems up to 150 psi

  • Vented triple-check vacuum breaker prevents backflow
  • Stainless steel body resists corrosion in potable water systems
  • Operates reliably from 33 to 140 degrees Fahrenheit
  • Withstands up to 150 psi working pressure
  • Meets NSF Standard 25 and NYC Health Code 81.47

Industrial Backflow Preventer

The Watts 9BD dual check valve with atmospheric vent protects potable water lines from back-siphonage and back-pressure in commercial and industrial plumbing systems. Its stainless-steel body handles temperatures from 33 to 140 degrees F and pressures up to 150 psi. The 3/8 inch MNPT connections allow direct installation on compatible pipework. This device meets New York City Health Code Section 81.47 and NSF Standard 25 requirements.

Code-Compliant Upgrade

It replaces non-vented check valves or older vacuum breakers that lack triple-check redundancy and atmospheric venting. The jump is worth it when local codes demand a vented dual-check design or when rubber components must comply with FDA food additive regulations. Installers gain a single assembly that satisfies both backflow prevention and vacuum breaking duties without adding separate components.

Compact Stainless Assembly

The unit measures 1 3/8 inches wide, 2 3/4 inches long and 1 3/8 inches high, so it fits tight mechanical rooms and equipment cabinets. Male NPT threads connect directly to female fittings, eliminating extra adapters. All rubber compounds meet FDA regulations, freeing specifiers from sourcing separate food-grade seals. No external power or control wiring is required for operation.

Highlights

  • Vented triple-check vacuum breaker prevents backflow
  • Stainless steel body resists corrosion in potable water systems
  • Operates reliably from 33 to 140 degrees Fahrenheit
  • Withstands up to 150 psi working pressure
  • Meets NSF Standard 25 and NYC Health Code 81.47

Specifications

BrandWATTS

Questions about this item

What thread size and type does the 3/8 in MNPT connection require?

The valve uses a 3/8 inch male NPT thread. Wrap PTFE tape or pipe dope on the male threads only, then tighten into a matching female NPT fitting until snug. Over-tightening female fittings often cracks the stainless body.

Which way must the atmospheric vent face during installation?

Install the valve with the vent port pointing downward or horizontal so water can drain. Mounting it vent-up traps water and defeats the vacuum-breaker function, a common error.

How often should the internal check modules be inspected or replaced?

Inspect the triple-check modules annually for debris or wear. Replace them if flow drops, leakage appears at the vent, or after any back-pressure event. Rubber compounds meet FDA and NSF 25 standards for potable use.

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