AquFlow Series 1000 and 2000 models with plastic diaphragm heads (whether it is made of PVC or PVDF) have the same internal seat designs inside the diaphragm heads. Due to the o-rings that are on these seats, removal from the diaphragm head can be tricky. br br The valve seats can be replaced without having to remove the diaphragm head from the pump or draining the oil, and only requires minimal necessary tools: br --Compressed air w about 30-40 psi in the tank and a blow gun attached to the air hose br --A pair of Channellock pliers br --A hook pick br For Series 1000: br --One 12" hose adapter with 34" MNPT br --One 12" hose adapter with 12" MNPT br For Series 2000: br --One 12" hose adapter with 1" MNPT br --One 12" hose adapter with 34" MNPT br br CONTACT AQUFLOW: br Website: br Phone: 949-757-1753 br E-mail: sales@aquflow.