The principle of the method specified is vertically compressing a length of pipe supported horizontally between two parallel flat plates moved at a constant speed which is dependent upon the diameter of the pipe, measuring the force and the deflection, plotting the force versus deflection, and calculating the ring stiffness as a function of the force necessary to produce a deflection of 0,03 nominal diameter diametrically across the pipe. Applies to pipes having a circular cross-section.
ISO 9969:1994 history
2016ISO 9969:2016 Thermoplastics pipes - Determination of ring stiffness
2007ISO 9969:2007 Thermoplastics pipes - Determination of ring stiffness
1994ISO 9969:1994 Thermoplastics pipes; determination of ring stiffness