FEBCO 850 Inline Double Check Valve Backflow Preventer
The FEBCO Series 850 Inline Backflow Preventer is a bronze double check valve assembly built for non-health hazard applications such as irrigation, fire line, or industrial processing service. Two independently operating, spring-loaded check valves stop contaminated irrigation water from reversing into your potable supply, satisfying national plumbing codes and local water authority cross-connection requirements. Available here in 1/2″ and 3/4″ NPT sizes with standard ball valve shutoffs.
This series includes a freeze sensor (mounted to one of the four test cocks) that can alert facility personnel when temperature nears freezing, once activated with an add-on BMS/IMS connection kit. The all-bronze body with silicone elastomers and stainless steel springs carries a 175 PSI maximum working pressure rating and is approved by the Foundation for Cross-Connection Control and Hydraulic Research (USC). This assembly is not approved for drinking, dishwashing, or other human-consumption plumbing per FEBCO’s product warning.
- Dual Independent Check Valves: Two spring-loaded check modules provide reliable protection against both back-pressure and back-siphonage.
- Freeze Alert Capability: Includes a freeze sensor that can notify facility or irrigation management systems when temperatures approach freezing (requires separate connection kit to activate).
- Compact, Serviceable Design: In-line repairable with a single access cover and no special tools required.
- Durable Bronze Construction: All-bronze body with replaceable check seats/discs and stainless steel springs for long service life.
- Code-Compliant: Meets ANSI/AWWA C510-92 and is approved by the USC Foundation for Cross-Connection Control and Hydraulic Research.
Specifications for the 1/2″ and 3/4″ sizes carried by DripWorks.
| Specification | Details |
|---|---|
| Assembly Type | Double Check Valve Assembly, Series 850 Small |
| Sizes Available | 1/2″ NPT, 3/4″ NPT |
| End Connections | NPT, ANSI/ASME B1.20.1 |
| Body Material | Bronze |
| Elastomers / Springs | Silicone / Stainless Steel |
| Max. Working Pressure | 175 PSI (12.1 bar) |
| Hydrostatic Test Pressure | 350 PSI (24.1 bar) |
| Temperature Range | 32°F to 140°F (0°C to 60°C) |
| Freeze Sensor | Included (requires add-on connection kit to activate alerts) |
| Approvals | ANSI/AWWA C510-92; USC Foundation for Cross-Connection Control and Hydraulic Research |
| Weight | 1/2″: 4.2 lb | 3/4″: 4.4 lb |
| Brand | FEBCO (Watts) |
| SKU | FEB85012 |
Step 1: Position the Assembly
Install the backflow preventer downstream of the water meter and upstream of any irrigation valves, timers, or fertilizer injectors, per your local water authority’s requirements.
Step 2: Connect the NPT Ends
Thread the inlet and outlet NPT connections into your supply line, using thread sealant appropriate for potable/irrigation piping.
Step 3: Open Shutoff Valves
Slowly open the ball valve shutoffs on both sides of the assembly to avoid water hammer.
Step 4: Test Annually
Have the assembly tested by a certified backflow tester at installation and at least once per year, or as required by local code.
