| 摘要 |
It is intended for irrigation and water supply networks where it is necessary to reduce the pressure downstream to desired levels. This is achieved by there being a sleeve, fig.1 and 2, number 5, which slides up and down on the piston, fig. 1 and 2, number 2, increasing or decreasing the opening of the piston ports Z from zero to the maximum, according to the downstream pressure which depends on demand (flow pattern), see fig. 3 and 4. The pressures acting on the sleeve are on one hand the tension of the spring which tends to keep the device open and, on the other, the downstream pressure which acts on the sleeve and tries to close the device when Q=0 (see description on page 3 line 48). The pressure thrust valve is necessary in irrigation and water supply networks where due to mainly hydrometric differences it is necessary to reduce the pressure in branches of the network to avoid malfunction or even destruction (see description page 1, line 40). |
