NPT & FUEL “B” FITTING -
1/4" NPT (National Pipe Thread)* x LH Fuel "B" Fitting** used to connect a manifold system or hard pipe to a hose with left hand thread, fuel type "B" fittings.
Left hand threaded connections all have a mark around the hex nut to identify that it is a left handed thread. To tighten these connections, the nut needs to be turned to the left (opposite of what most people are used to). This ensures that fuel connections stay with the fuel side of the torch and cannot be connected to the oxygen side of the system.
*NPT (National Pipe Thread) requires sealant -
**B fittings do not require sealant.