Bzcovac PVB-4A/4ALF Float & Bonnet Complete Repair Kit — 1/2–3/4 in Top-Half Assembly with O-rings & Poppet

The Bzcovac 4A00407 Float and Bonnet Complete Repair Kit restores the top half of Apollo/Conbraco PVB-4A and PVB-4ALF 1/2"–3/4" pressure vacuum breakers to factory-like operation.

This kit contains every component needed to rebuild the upper assembly of compatible Apollo/Conbraco PVB 4A Series backflow preventers: O-ring, poppet assembly, bonnet assembly, bonnet O-ring, float cage and canopy. Designed as a direct-fit service kit, it replaces worn parts that commonly cause leaks, reduced venting performance, or float malfunction so you can return the device to reliable backflow prevention without replacing the entire valve.

How does this kit bring a PVB back to proper backflow prevention?

Worn sealing surfaces, degraded seats and a damaged float are frequent reasons a pressure vacuum breaker fails to stop back-siphonage. The 4A00407 replaces those upper-half components with factory-equivalent parts to restore the venting and check functions.

• Includes new poppet and reversible silicone seat disc for effective seating
• Fresh O-rings and bonnet seal eliminate top-half leaks
• Float cage and canopy restore correct float movement and vent timing

What parts are included and why are they important?

The kit supplies the full set of components required to service the top half of the PVB: sealing elements, moving parts and the float mechanism. Each piece is selected to interact correctly with Apollo/Conbraco 4A Series geometry so service is straightforward and reliable.

• Poppet assembly with captured spring—controls check action
• Reversible silicone seat disc—extends service life and simplifies replacement
• Bonnet assembly plus bonnet O-ring—restores proper compression and sealing
• Float cage and canopy—ensures correct float travel and vent timing

Will this kit handle freezing conditions or corrosion-prone locations?

The original PVB design includes a standard integral freeze-relief feature and stainless-steel hardware where needed; this repair kit maintains those protections when correctly installed in the top half of the device. The kit’s materials support reliable operation in seasonal freeze–thaw cycles and resist corrosion at the handle and fasteners.

• Freeze-relief design preserved when top-half components are replaced
• Stainless steel handles and nuts reduce corrosion risk on shutoffs
• Replaceable parts avoid full valve replacement after intermittent freezing events

How easy is it to install this top-half repair kit?

Technically straightforward for a trained technician, the kit is intended as a direct top-half swap for Apollo/Conbraco 4A Series 1/2" and 3/4" models. Basic field tools and adherence to local plumbing codes are required; follow manufacturer torque and reassembly guidance to ensure safe operation.

• Direct-fit components minimize machining or modification
• Captured spring and reversible seat simplify reassembly and alignment
• Recommended for certified technicians or qualified maintenance personnel

Who is this for: The Bzcovac 4A00407 Float and Bonnet Complete Repair Kit is aimed at plumbing contractors, facility maintenance teams and irrigation specialists servicing Apollo/Conbraco PVB-4A and PVB-4ALF 1/2"–3/4" backflow preventers. If you need to restore venting performance, replace failed seals, or maintain freeze-relief capability without replacing the entire valve body, this kit provides the OEM-style parts required to return the top half to reliable operation. It’s an economical choice when the body remains sound but the upper assembly shows wear.