This combination elbow is made to adapt plastic pipe, with a hose barb fitting, to a male thread. These are commonly used in vacuum boosters, manifolds, and cannisters throughout a maple sap tubing system, where a valve or other threaded fitting is needed.
The aggressive hose barbs lock onto the plastic mainline tubing or black plastic water pipe, once tightened down with a hose clamp, for a leak-free hold. The standard male pipe thread (MPT) should be thread taped before fastening to ensure a leak-free seal. Using this elbow eliminates any pooling areas at the elbow, because the fitting is molded smooth on the inside.