Check up to five results to perform an action.
There are several variations of pipe threads. Thread forms include the Dry Seal American Standard Taper Pipe (NPTF), National Pipe Straight Threads for Mechanical Joints (NPSF), and dry seal American Fuel Internal Straight Pipe Thread (NPSF). Each series is normally identified by the abbreviated letter designation.
The NPTF thread is recommended for hydraulic service. The thread series is used on both male and female ends and forms a seal by the interference fit at the root and crest of the matting threads. The NPTF male also has an internal chamfer of 30° which allows it to seal at the seat with female NPSM pipe swivels. The NPSM is a straight thread and sealing is obtained by the mating of the 30º seats of the male and female ends.