What type of conduit fitting is typically used in the middle of a long run of rigid metal conduit to aid in wire pulling?

The appropriate choice for aiding in wire pulling during a long run of rigid metal conduit is the C fitting. C fittings, also known as pull elbows or pull boxes, are specifically designed to provide a way to make a change in direction while also allowing for easier access for pulling wires through conduits. They have a larger radius compared to other fittings, which reduces stress on the wires and makes pulling them through the conduit smoother and more efficient.

In contrast, elbow fittings are typically used to change the direction of conduit runs but may not provide the necessary access for wire pulling. Coupling fittings are utilized to join two lengths of conduit but do not offer any assistance with wire pulling. Connector fittings connect conduit to electrical boxes or other enclosures but do not serve a pulling function. Thus, the design and function of the C fitting make it the most suitable choice for this application.