MLC Fittings combine the positive feature of high reliability with a simple installation technique. The fittings do not require any special tools. The permanent pipe joint is achieved by compression i.e. by tightening the nut against the coned-shaped olive. The profiles of the two pieces are designed to cause a progressive shrinkage of the coned-shaped olive and to distribute the compression forces across the contact surface. A seal housing has been designed with a special slip-proof profile called 0-rings that come into direct contact with the pipe.