Plastic barb fittings are an effective, economical alternative
to brass. They are easy to use, and work with most flexible plastic tubing. They are durable, lightweight, and can be re-used. For sizing, match the inside diameter of the tubing being used to the outside diameter of the barb.
BrassCraft brass bar stock adapters are commonly used
to connect nominal copper pipe to iron pipe or iron pipe fittings. Bar stock adapters are connected to copper pipe using standard soldering/sweating procedures.