5 Apparatus5.1 Compressive testing machine, capable of a constant rate of crosshead movement, via a pair ofparallel plates (5.2), as appropriate to the nominal diameter of the pipe in conformance with Table 1, withsufficient force and travel to produce the specified diametric deflection (see Clause 8). 5.2 A pair of hard and rigid plates, through … Continue reading ISO 9969 Thermoplastics Pipes — Determination of Ring Stiffness / Testing Equipment