The Kelly Valve is an essential part of the Drill String. Back before the Top Drive Assembly, a Rotary Kelly was the tool that drove the drill string. The Upper Kelly Valve ran between the Swivel and the top of the Kelly. It had Left Hand Threads to be able to make up to the Swivel and the top section of the Kelly. It can still be produced but is not part of the configuration for a Top Drive Assembly.
Initially the Lower Kelly Valve was installed below the Kelly and the beginning of the Drill Pipe. Even though the Rotary Kelly has been virtually replaced by the Top Drive Assembly, the Lower Kelly Valve is still an essential part of the Drill String. It is installed below the Top Drive & just before the Drill Pipe Starts. The Lower Kelly Valve is primarily built as a Two-Piece Valve. The center connection is where you access the internal parts of the valve. Because spacing can be an issue at the top of the string, we also offer a One-Piece Valve for most sizes. The internal parts of a One-Piece valve can only be reached thru the Box connection. The smaller size Valves have such a small ID that the parts cannot be accessed. In this case, a Two-Piece Kelly Valve is the only option.
Upper, Lower, One-Piece or Two Piece Kelly Valves all can stop the flow from above or below. Ours are pressure tested from above and below the Valve, are rated as Class 2 Valves.