Hydraulic characteristic of selected installation valves installed on various pipes materials

Abstract

Presented studies covered determination of minor pressure losses and values of minor loss coefficients for two selected installation valves: water control globe valve and angle valve, both DN 15. The tested valves were installed on three pipes, including PP 20x3.4 mm, PEX-Al-PEX 16x2.0 mm and Cu 15x1.0 mm. In order to reflect the real operating conditions of the angle valve, the elastic PVC pipe was used. Our researches were performed on the laboratory installation, for the variable flow rate. The obtained results of laboratory studies showed the clear dependence between minor pressure loss and minor loss coefficients of studied valves, and water flow rate (Reynolds number), degree of valves’ closure and, in some cases, manner of valves installation and material of pipes. The greatest values of minor pressure loss coefficients, of mean values relevantly statistically grater, were determined for the tested valves installed on the PEX-Al-PEX pipeline.

Hydraulic behavior of valves used in building water supply systems

“…It should also be noted that the devices of each market have their constructive, geometric, and material characteristics normally used, thus, there is an intrinsic imprecision when transferring international research and technical results. Another difficulty is that, as shown by Poręba et al (2018), the minor head loss in valves can be influenced by the piping material in which they are installed, as well as by the set of couplings used in the test apparatus.…”

“…The observation of the vertical axis of Figure5Dshows that the scale of the K value was much larger than those obtained for the other openings. According toRazaey (2020), in the initial stages of valve opening, the rate of change in the head loss coefficient is very pronounced, thus explaining this discrepancy.With their work,Poręba et al (2018) evaluated minor head losses coefficients for DN 15 angle and globe valves, for variable degrees of closure and different values of flowrate, as was done in this research. Their results showed a dependence between the head loss and coefficients with the degree of valve closure, in the same way as detected in this study, and as the tested valves had different construction, the authors also found significant differences between the head loss for angle and globe valves for the same opening/closure degree.…”

“…These values were lower for some valves, such as 506, 697, and 1,949%, for Pr2, Pr1 and Ga2, respectively; and higher for others, such as 122,084, 288,527 and 1,090,111%, for Bm1, Bw1 and Bt1, respectively. When studying DN 15 angle valves,Poręba et al (2018) found that an increase of minor loss coefficient Hydraulic behavior of valves used in building water supply systems average Re correlated better with hfl, K, and Leq. By PCA, it could be possible to determine that ball valves have greater flow blocking capacity than gate valves, even though both are intended for this purpose, due to its high head loss already at 50% of relative opening, which implies that it can exert some control to the flow.…”