6.8 机械耐力 Mechanical endurance

6.8.1 总则 General

The test described is a type test (laboratory test), not a quality control test carried out during manufacture.

This clause specifies a test method for verifying the mechanical endurance or resistance to wear of the mechanical elements of urinal flushing valves.

The test consists of subjecting a urinal flushing valve to a specified number of operations in order to establish its behaviour over time.

Tests are carried out at a dynamic pressure of (0,25 ± 0,02) MPa ((2,5 ± 0,2) bar) with cold water.

6.8.2 仪器 Apparatus

A suitable test rig and water supply circuit to allow normal operation of the flushing valve within the parameters described.

6.8.3 Procedure

Connect the flushing valve to be tested to the water supply circuit, adjusted to deliver cold water at a dynamic flow pressure of (0,25 ± 0,02) MPa ((2,5 ± 0,2) bar):

— operate the flushing valve and measure the rate of flow whilst the flush is being delivered;

— measure also the volume of flush water delivered – which shall comply with one of the values specified in Table 16;

— wait until 2 s after the flow has stopped;

— subject the flushing valve to 70 000 flushing cycles;

— if the valve is battery operated, the battery can be changed during the test; the number of times the battery is changed shall be recorded.

6.8.4 Requirements

— Flow rate shall still comply with the appropriate minimum requirement specified in Table 16;

— flush volume measured under the same supply conditions as those specified for the test shall not vary by more than 25 % from the volume delivered initially;

— requirements of 4.6 (leaktightness) shall be maintained.