Commercial Backflow Prevention System — Apollo 4A Series

A properly installed and maintained backflow prevention assembly is required on virtually every commercial water service connection in the United States. The Apollo 4A Series is one of the most widely specified backflow prevention lines in the industry, covering Reduced Pressure (RP), Double Check (DC), and Pressure Vacuum Breaker (PVB) assemblies from 1/4" through 12". This guide covers the complete Apollo backflow system — component selection, installation requirements, maintenance intervals, and code compliance.

Required Components

• Backflow Preventer Assembly — RP, DC, or PVB per AHJ requirements. Apollo 4A Series in the appropriate size and configuration.
• Isolation Valves — Integral to the 4A Series assembly. Ball valve, OS&Y gate, or NRS gate per local requirements.
• Test Cocks — Integral to RP and DC assemblies. Required for annual differential pressure testing.
• Relief Valve Drain — For RP assemblies only. Full-bore floor drain required below the relief port.
• Strainer (recommended) — Install an Apollo 59 Series strainer upstream of the backflow assembly on dirty water supplies to protect check valve seats.

→ Shop Apollo Backflow Preventers  |  → RP vs DC vs PVB Selection Guide

Installation Requirements

• RP assemblies must be installed horizontally with the relief port facing down. Minimum 12" clearance below the relief port to floor or drain. Must be accessible for annual testing.
• DC assemblies can be installed horizontally or vertically (flow up). Must be accessible for annual testing.
• PVB assemblies must be installed at least 12" above the highest downstream outlet. Cannot be subject to downstream backpressure.
• All assemblies must be protected from freezing, physical damage, and submersion.
• Clearance — Provide minimum 12" side clearance and 12" overhead clearance for testing access on all assemblies.

Annual Testing & Maintenance

RP and DC assemblies require annual differential pressure testing by a state-certified backflow tester in most jurisdictions. Test reports must be submitted to the local water authority and maintained on file. PVBs typically require annual inspection.

When an assembly fails its annual test, rebuild with genuine Apollo OEM service kits to restore the assembly to original performance and maintain certification documentation. Rebuild kits are available for all 4A Series sizes and configurations.

→ Shop Apollo Backflow Repair Kits

Code & Listing

• ASSE 1013 listed — Reduced Pressure Zone Backflow Preventers (RP)
• ASSE 1015 listed — Double Check Valve Assemblies (DC)
• ASSE 1020 listed — Pressure Vacuum Breakers (PVB)
• NSF/ANSI 61 certified for potable water contact
• AWWA approved on applicable sizes
• Made in USA — BAA/BABA compliant