B&G Sprayer PV 266 Check Valve and Brass Pump Cylinder

The check valve is one of the parts of a B&G Sprayer that need replacing from time to time. There are a couple of signs to look for which will tell you that the PV266 check valve needs replacing.
The first can be seen by simple inspection. As you can see in the picture, a check valve that is new or in good working condition is of regular diameter and thickness. When the check valve is swollen, it is easy to see that chemicals have damaged the material; check valve will be thicker and much wider in diameter than when it was new.
The next obvious sign of a valve that needs replacing is in the sprayer's performance. When the PV266 valve becomes weak or swollen, the sprayer cannot be pressurized properly. The function of the check valve is to allow the operator to pump air into the tank, pumping the plunger up and down until tank is pressurized properly. On the down stroke, air is pushed pass the check valve and into the sprayer tank. On the up or return stroke, the check valve closes which prevents liquid (from inside of tank) from being pulled out and keeps tank pressurized.
A weak or damaged check valve will not allow the tank to be pressurized properly and will also allow liquid contents of tank to be pulled up into the brass pump cylinder.

When replacing the PV 266 check valve, make sure that the old valve is removed entirely. A very soft, weak valve will often pull apart as it is removed. Small pieces of the valve will then need to be removed from the brass pump cylinder PO267. As shown in the pump cylinder/ PV266 picture, the check valve has a small nipple on one side. This nipple helps hold the part to the cylinder. It is this nipple that can easily break off inside of the cylinder. This broken piece must be removed prior to attaching new valve.

Additional repair and maintenance information as well as schematics and diagrams can be found in the B&G Sprayer Manual, a PDF web page.