BS ISO 12809:2011 pdf download – Crop protection equipment — Reciprocating positive displacement pumps and centrifugal pumps — Test methods
4 Accuracy of measurements
Temperatures shall be measured with an accuracy of ±1 °C.
Length shall be measured with an accuracy of ±1 mm.
Suction pressure shall be measured with an accuracy of ±1 kPa.
Delivery pressure shall be measured with an accuracy of ±1 % of the full scale. The full-scale value shall not exceed twice the maximum value that has to be measured during the test.
Rotating speed shall be measured with an accuracy of ±1 %.
Flow rate shall be measured with an accuracy of ±1,5 %.
Load torque shall be measured with an accuracy of ±5 %, at least for values greater than the 25 % of the maximum torque.
5 Test liquid
Clean water without solids in suspension.
6 General test conditions
6.1 Test bench
6.1.1 The test bench shall have a main circuit containing the devices for fow control and pressure adjustment. To simulate the installation of the pump on the sprayer, the test bench shall have a “nozzle line” (section A in Figure 1) and an extra circuit (section B in Figure 1) able to simulate the cleaning conditions, with part of the fow coming back directly to the suction line of the pump.
6.1.2 The suction line connects the pump with the tank. It shall be ftted with an air inlet valve, a suction pressure adjustment valve and a suction pressure gauge. For self-priming pumps, the h value shall be (400 ± 100) mm. For non-self-priming pumps, the h value shall be (−100 ± 20) mm. The start of the suction line shall be free, without non-return valves. See Figure 1.
6.1.3 The delivery line shall be ftted with a pressure gauge, a pressure adjustment valve and the device for fow rate measurement (see Figure 1). The output of the delivery line shall be connected to the tank in order to guarantee the re-circulation of the test liquid. Ensure that the back fow does not create turbulence in the suction line.
6.1.4 The extra circuit shall be ftted with a by-pass fow-rate adjustment valve and a shut-off valve able to isolate this part of the circuit.
6.1.5 The level of the liquid in the tank shall be equal (±10 mm) to the top of the pump housing. Set the level when all the lines are flled with the test liquid.
6.2 Installation of pump
The pump shall be fxed on the test bench following the indications given by the manufacturer, and especially those concerning the positioning of the pump and the dimension of the fxing device.
The pump shall be connected to the test bench by non-collapsible pipelines, both at the suction and delivery side.
The internal diameter of the suction line shall be as follows:
— for hoses, equal to or greater than (max. + 5 %) the internal diameter indicated by the manufacturer;
— for fttings, equal to or greater than (max. + 20 %) the internal diameter indicated by the manufacturer.
The internal diameter of the delivery line shall be equal to or greater than (max. + 50 %) that indicated by the manufacturer.
6.3 Environmental conditions
The air and testing liquid temperatures shall be not less than 10 °C and not more than 35 °C, except for centrifugal pumps, for which the testing liquid temperature shall be not less than 20 °C and not more than 30 °C.
6.4 Pressures
6.4.1 Suction pressure
The suction pressure, expressed in kilopascals (kPa), shall be measured at the suction ftting indicated in 6.1.
6.4.2 Reference suction pressure The reference suction pressure value shall be (−25 ± 2) kPa. That reference value shall be set once at the beginning of the test (by means of valve 4, shown in Figure 1) at the maximum rotating speed indicated by the manufacturer and with the delivery pressure set to (5 ± 1) % of the rated pressure. It will rise during the test, reducing the rotating speed, because of the reduction of the pressure drop.