Angle drain valve 1/2 Inch. Connects 1/2 Inch pex or polybutylene. Flair-it fittings are an excellent solution for do-it-yourself home plumbing repair. They require no special tools. Installation is easy: slide the nut along the pex pipe, rock the fitting into the pex pipe, slide the nut back along the pipe and hand tighten the nut onto the fitting. The double threaded nut will thread onto the pipe and the fitting, forming a tight seal. If the fitting leaks, tighten the nut a few more turns.