An automatic portable preassure testing RIG to determine the performance of the GRE composite pipes under various stress ratios

Abstract

This product is a novel automated pressure test rig to perform Ultimate Elastic Wall Stress (UEWS) test. It is fabricated using Rotex make solenoid valves controlled using NI DAQ and Labview interface. The test rig is designed to conduct pressure testing of GRE pipes in accordance with ISO 14692 through ASTM D2992 document. The test rig is capable of automatically testing under five stress ratios by a combination of internal pressure and axial loadings through inclusion of indigenous design of pressure intensifier. [pure axial (OH : 1A), hoop to axial (1H : 1A), pure hydrostatiC (2H : 1A), Quad hoop to axial loading (4H : 1A) and pure hoop (1H : OA)l, The test rig also allows for short term tests such as UEWS test where the strain response can measured and analyzed offline to determine the initial failure of the pipe. The tubes are further tested until the weepage failure occurs. The failure envelope for different stress ratios are mapped and provides a design limits for engineers to design the composite pipes. The results are associated with ASTM D2992 type of regression testing for the determination of long term strength of composite pipes.