Wilkins 423-20 Factory Replacement Bonnet for 1" Model 420
Replacement bonnet (part 423-20) for the Wilkins 420 series 1" pressure vacuum breaker. This factory-authorized Zurn/Wilkins bonnet is a direct-fit service part designed to restore proper sealing and dependable operation on 1-inch Model 420 assemblies. Use this bonnet when the original bonnet shows wear, cracking, or leak paths after prolonged service; it helps extend the life of the valve without full assembly replacement.
Designed for professional repair and routine maintenance, the 423-20 bonnet installs quickly and accepts the standard O-rings and internal seals specified for the 420 series. It is sold individually and is also included in factory repair kits (RK1-420 and RK1-420FK) that contain poppet, seals, and related components.
- OEM part number: 423-20 — compatible with Wilkins Model 420 (1").
- Direct replacement for 1" Wilkins 420 and compatible 420XL configurations where specified.
- Included in factory repair kits (RK1-420 / RK1-420FK) for quicker service installs.
- Works with the standard 420 parts breakdown and recommended seal kits—replace seals when installing the bonnet.
- Intended for licensed plumbers and service technicians; follow manufacturer instructions and local codes during installation.
Choose the 423-20 factory bonnet to maintain reliable backflow protection and simplify field repairs on Wilkins 420 1" assemblies.