The best inline double check valves protect potable water systems by preventing backflow due to back-siphonage or backpressure. This guide highlights five top picks suited for different applications, from residential plumbing to commercial installations. Read on to identify which valve best fits your system type, installation space, and maintenance preferences. The following table summarizes each option’s strongest use case and notable design traits for quick comparison.
| Product | Best For | |
|---|---|---|
| Febco LF850 Series | Residential/Small commercial with freeze concerns | Lead-free copper silicon alloy, freeze sensor compatibility |
| Watts LF007 Series | Non-health hazard backflow prevention in tight spaces | Lead-free bronze, top-entry, modular design |
| Watts LF7RU2-2 | 3/4-inch dual check for compact piping | Lead-free brass, one-piece construction |
| Midline Valve 372U422 | Inline spring-loaded, lead-free option | Heavy-duty brass, ANSI-compliant threads |
| ChillWaves Inline Check Valve (2″) | Medium to large-line backflow prevention | Brass with stainless steel spring, vertical/horizontal install |
Febco LF850 Series Inline Double Check Valve
The Febco LF850 Series uses a lead-free copper silicon alloy body with NPT connections and quarter-turn shutoffs. It features two in-line independent positive seating check modules and captured springs, designed for continuous-pressure piping and cross-connections. A top-mounted test cock arrangement supports serviceability. Best for homeowners or small facilities needing reliable backflow prevention in non-health hazard applications. Cautions: ensure proper freeze protection and compliance with local codes when integrating a freeze sensor, as not all systems require sensor monitoring.
Watts LF007 Series Inline Double Check
The Watts LF007 Series is a 1″ lead-free bronze double check valve designed for non-health hazard systems. It provides backflow prevention in continuous-pressure piping at cross-connections and service line entrances. Its compact, modular design with top-entry access supports straightforward maintenance and inline repairs. It is best for installations where space is limited and easy maintenance is a priority. Limitation: ensure compatibility with water authority requirements for your jurisdiction, as some systems have stricter approvals for bronze components.
Watts LF7RU2-2 Dual Check Valve
This 3/4-inch dual check valve from Watts provides lead-free brass construction in a compact one-piece design. It is suitable for non-health hazard backflow prevention on smaller lines. Best for tight piping spaces where a simpler, robust dual-check arrangement is desired. Choose this option if ease of installation and a single, compact unit are priorities. Limitation: verify that the unit’s dimensions fit your piping layout, as some installations require more clearance around test cocks and connections.
Midline Valve 372U422 Inline Check Valve
The Midline Valve 372U422 is an inline spring-loaded check valve with a heavy-duty brass body and disc. It emphasizes dezincification resistance, corrosion resistance, and lead-free construction with ANSI-compliant threaded ends. Best for systems needing a reliable, single-direction flow valve with solid material durability. Limitation: performance depends on proper spring tension and line pressure; verify the valve’s spring characteristics match your system’s pressure range.
ChillWaves Brass In-Line Spring Check Valve
The ChillWaves 2″ inline check valve is a brass unit with a stainless steel spring designed for backflow prevention. It supports vertical or horizontal installation and suits larger line sizes where backflow protection is needed across irrigation or industrial setups. Best for users prioritizing a robust, straightforward inline check on mid to large-diameter pipes. Limitation: larger size may require more space and careful mounting to maintain reliable operation.
Buying Guide
Key considerations when selecting an inline double check valve:
- Water system application: Choose a unit designed for non-health hazard backflow prevention in residential, commercial, or industrial environments.
- Material and lead content: Lead-free copper silicon alloy, bronze, or brass options affect durability and code compliance. Match material to water quality and local code requirements.
- Connection type and size: Ensure NPT or threaded ends match your piping. Verify space and access for maintenance and test cocks.
- Maintenance and serviceability: Some models feature top-entry access or replaceable discs and seats for easier inline service.
- Freeze protection: If you operate in freezing climates, consider valves with freeze-sensor compatibility or dedicated protection options.
- Installation orientation: Some valves support vertical or horizontal installation; confirm compatibility with your system layout.
FAQ
- What is an inline double check valve used for?
It prevents backflow in potable water systems, protecting against back-siphonage and backpressure in non-health hazard applications.
- What material should I choose for potable water safety?
Lead-free materials like copper silicon alloy, bronze, or brass are common and typically meet relevant standards for drinking water systems.
- Do these valves require maintenance?
Many models offer inline serviceability with test cocks or replaceable components; plan for periodic inspection and testing per code requirements.
- Can I install these valves in tight spaces?
Yes, compact modular designs and top-entry access exist, but verify space for installation, access, and future servicing.
- Is freeze protection important for backflow preventers?
In freezing climates, freeze sensors or protective measures help prevent valve damage and maintain reliability.
- How do I choose between different brands?
Compare material, size, installation orientation, maintenance features, and compatibility with your local plumbing codes and service needs.