Experimental investigations of guide rings made of UHMWPE and PTFE composite in water hydraulic systems

In the present work two materials of guiding elements were tested in water hydraulic. During investigations of hardness conducted for stuffing box packings in water hydraulic systems an analysis of proper selection of piston rod guiding elements has also been carried out (ø45f7, Ra = 0.07–0.20 μm, Rm < 2.5 μm). Working piston rod has been used for investigations made of chromium-nickel steel AISI 431 (Cr = 16.7%, Ni = 2.08%). Some of the guiding elements, after proper selection of the material, could be still used, despite damaged seal. The tests have been performed maintaining water pressure on the sealing at a level of p = 8±1 MPa and the average velocity of the piston rod of v ≈ 0.35 m/sec. Water temperature during investigations was regulated within the range of Tmin = 291 K and Tmax = 305 K. Variable value of friction coefficient has been obtained for the guide rings made of PTFE composite with the change in piston rod velocity. Application of guide rings made of UHMWPE has been estimated negatively.