The AR45 Check Valve Kit (AR42816) is the genuine Annovi Reverberi rebuild kit for the AR45LFP diaphragm pump. Six valves and six green Viton gaskets, enough to rebuild all six valve positions in one box. When your AR45's pressure starts bouncing, this is the fix. Key Features Six valves, six Viton gaskets: Rebuilds all six valve positions on one AR45LFP. One inlet and one outlet check valve per chamber, across all three chambers. Genuine OEM Annovi Reverberi: Box code COD.42816, with the correct seat geometry for the AR45. Generic valve sets seal imperfectly and start surging again in weeks. Green Viton gaskets: Viton is the SH-safe elastomer. It holds up to sodium hypochlorite where a Buna/NBR gasket breaks down. Fixes bouncing pressure: Worn check valves are the classic cause of a surging AR45. New valves and seats let the chambers seal so pressure holds steady. AR45LFP only: Fits both the gauged (2018 to June 2024) and no-gauge (post June 2024) versions. It's not a universal AR kit. Specifications Kit contents 6× valve (OEM pos 9) + 6× green Viton gasket (OEM pos 10) Valve material Blue plastic poppet Gasket material Green Viton (fluoroelastomer) OEM kit code AR42816 (COD.42816) Fits AR45LFP diaphragm pump (pump code 31878) Rebuilds All six valve positions on one pump Chemical compatibility Sodium hypochlorite, surfactants Host pump (for reference) AR45LFP, 11.4 GPM at 290 PSI What's Included 6× valve (OEM position 9) 6× green Viton gasket (OEM position 10) Fits the AR45LFP only, both the gauged and no-gauge versions. This kit doesn't include diaphragms. If your pressure is dropping steadily rather than bouncing, you want the AR45 Diaphragm Kit instead. It also won't fit other AR pumps. The RK, RR, RMW, AR30, AR40, and AR252 families all use different valve kits. This one's for the AR45. No exceptions. How It Works The AR45 is a 3-chamber diaphragm pump. Each chamber holds two one-way check valves, one on the suction side and one on the discharge side, that open and close on every diaphragm stroke to push fluid one direction. Run SH and abrasive mixes through them long enough and the valve poppets and their green Viton seat gaskets wear out and stop sealing. The pump surges, and bouncing or fluctuating pressure is the classic worn-check-valve symptom. This kit replaces all six valves and all six seats so the chambers seal and pressure settles back down. It bolts in with basic tools. If you want the full procedure, download the AR45 Diaphragm Pump rebuild manual here. Pairs Well With AR45 Diaphragm Kit Soft Wash Sprayer - AR45 AR45 Plumbing Kit AR45 Soft Wash Bundle Frequently Asked Questions My AR45's pressure is bouncing. Is it the check valves? Probably. Fluctuating or bouncing pressure on an AR45 is the classic worn-check-valve symptom, and that's what this kit fixes. A steady, sustained pressure drop that stays down is a different problem. That one points to the diaphragms, which is the AR45 Diaphragm Kit (AR43238). Will the AR42816 kit fit my other AR pump? No. The AR42816 is specific to the AR45LFP. The other AR series use their own kits: AR2864 for the RK and RR families, AR1917 for the AR30 and AR40, AR42123 for the RMW and RMV. Ordering the wrong series' kit is the most common mistake with AR valve kits, so check your pump before you buy. What's actually in the AR45 check valve kit? Six valves and six green Viton seat gaskets, which is enough to rebuild every valve position on one AR45LFP. The pump has three chambers, each with an inlet and an outlet check valve, so six valves covers the whole pump. Most operators keep this kit and the diaphragm kit on the shelf so a worn-valve repair is an hour, not a parts hunt.
