What type of fitting should be used where a conduit run enters or leaves a dispenser?

A sealing fitting is the appropriate choice where a conduit run enters or leaves a dispenser because it effectively prevents the ingress of explosive gases or vapors into the conduit system. This is especially critical in hazardous locations, where the presence of flammable materials can pose serious safety risks. Sealing fittings provide a barrier that contains any potential explosion within the fitting, thereby protecting the surrounding environment and equipment.

In the context of dispensers, which may be exposed to volatile substances, sealing fittings also work to maintain the integrity of the conduit system by containing any potential contaminants. They are designed to be installed in areas where the potential for ignition exists and can minimize the risk of fire or explosion due to external sources of ignition.

Other types of fittings, such as an explosionproof reducer, may be useful in different contexts but do not serve the specific purpose of sealing against gases at the conduit entry points. A standard coupling does not offer the necessary protection against the hazardous conditions expected in and around dispensers. Threaded connectors are useful for joining two pieces of conduit but do not provide adequate sealing against explosive environments. Thus, the sealing fitting is the optimal choice for this application.