Patent attributes
Flapper valves may be provided in fluid transportation systems. The flapper valves comprise a body adapted for assembly into the system. The body comprises a first sub and a second sub which are removably assembled to each other. A passage is defined in the body which extends through the first and second subs. A seat is removably mounted in the passage. The seat is accessible by disassembling the first sub and the second sub. The valve also has a service port. A cap removably closes the port. A flapper is removably a mounted within the service port for pivoting movement between a closed position and an open position. In the closed position the flapper shuts off back flow through the passage. In the open position, the flapper allows fluid flow through the valve. The flapper is accessible by removing the cap from the service port.
