7.5 水力特性 Hydraulic characteristics
7.5.1 概述 General
This subclause specifies a test method with which the following is measured, using a given pressure:
— flush flow rate;
— impact force;
— flush time;
— flush water volume;
— pressure increase (water hammer) ΔP while closing the tap.
In this subclause, the corresponding requirements are specified.
7.5.2 试验方法 Test method
7.5.2.1 General
The WC flushing valve is assembled with a flushing pipe corresponding with the nominal size DN in accordance with Table 20.
Figure 20 — Flushing pipe
Table 20 — Flushing pipe dimensions
7.5.2.2 Principle
The tests shall be performed with cold water.
Before each test, the valve to be tested is operated five times before taking the measurement (air bleeding).
The tests are performed according to the sequences indicated in Table 21.
Table 21 — Sequences of tests
7.5.2.3 Procedure for flow rate / impact force test
For the measurement of flow rate/impact force, the tapware is to be adjusted and operated in accordance with the manufacturer’s information, depending on the valve design type.
To set the dynamic pressures and measure the impact force, the tapware shall be held in an open position.
7.5.2.4 Procedure for flow rate / volume test
For the measurement of the flow rate / volume according to the flow rate curve, the adjustment of the tapware is not
modified, regarding to the precedent test.
The flush time is to be taken from the start of activation.
The measurement is to be taken by simultaneously recording pressure and flow rate as a function of time.
The volume can be measured by continuous recording of the flow curve.
To check the requirements in accordance with Figure 21, depending on the valve design type according to 7.2, the
course of the flush flow rate curve in relation to time is evaluated from the diagrams which have been recorded during the test.
7.5.2.5 Test apparatus
The test apparatus shall be in accordance with EN 12541.
7.5.2.6 Impact force measuring instrument
The calibration of the impact force measuring instrument shall be in accordance with EN 12541.
7.5.2.7 Definitions
Qmin minimal flush flow rate to be achieved or exceeded after 2 s of operation
Qs significant flush flow rate; 0,85 × Qmin
T1 time period during which Qs for servo-controlled hydraulic flushing valves in accordance with 7.2.1.1 shall be maintained to obtain a volume of water supplied of 6 l
T2 time period during which Qs for servo-controlled hydraulic flushing valves in accordance with 7.2.1.1 shall be maintained to obtain a volume of water supplied of 9 l
T3 time period during which the flush flow rate for direct controlled flushing valves in accordance with 7.2.1.2 reaches Qmin
T4 time period during which Qs for direct controlled flushing valves in accordance with 7.2.1.2, after exceeding Qmin, shall be maintained to obtain a volume of water supplied of 6 l.
T5 time period in which Qs for direct controlled flushing valves in accordance with 7.2.1.2, after exceeding Qmin, shall be maintained in order to obtain a volume of water supplied of 9 l.
0 Origin of corresponding graph for time at start of activation of control device
A on x-axis of time 2 s
A1 on x-axis of time T3
B on x-axis of time T1 or T4
C on x-axis of time T2 or T5
D on y-axis at Qs = 0,85 × Qmin
E on y-axis at Qmin
H intersection of a vertical line from A and a horizontal line from E
H1 intersection of a vertical line from A1 and a horizontal line from E
M intersection of a vertical line from B and a horizontal line from D
N intersection of a vertical line from C and a horizontal line from D
Key
1 V = 6 l
2 V = 9 l
Figure 21 — Flush flow rate/flush time diagram
7.5.3 在较低动压下测试流速 / 冲击力 Testing of the flow rate / Impact force at lower dynamic pressure
7.5.3.1 Procedure
The procedure takes place in accordance with 7.5.2.3.
7.5.3.2 Requirements for flush flow rate impact force for valves DN 20
For a set dynamic pressure of (0,12+ 0,005) MPa ((1,2+ 0,05) bar), the impact force and flush flow rate (Qmin) shall correspond at minimum with the values in the lower dynamic pressure range given in Table 22.
7.5.3.3 Requirements for flush flow rate/impact force for valves DN 25 and DN 32
For a set dynamic pressure of (0,08+ 0,005) MPa ((0,8+ 0,05) bar), the impact force and flush flow rate (Qmin) shall correspond at minimum with the values in the lower dynamic pressure range given in Table 22.
7.5.4 在较低动压下测试流速/冲水量 Testing of the flow rate / Volume at lower dynamic pressure
7.5.4.1 Procedure
Testing in the lower flow pressure range is performed in accordance with Figure 21. In a graphic representation, points A-E, M, N are recorded and their conformity with the requirements in Table 21 is checked, depending on the valve design type.
Flow pressure, flush flow rate and time shall be recorded.
The flush times shall be evaluated in accordance with Table 21, depending on valve design type.
7.5.4.2 Requiremegnts for WC flushing valve DN 20
For a set dynamic pressure of (0,12+ 0,005) MPa ((1,2+ 0,05) bar), the flush flow rate, flush water volume and flush time shall correspond with the following requirements:
• Class 6 - WC flushing valves (intended for the release of 6 l or 6 l to 9 l):
The flush flow rate (Qmin) shall correspond at Point H/H1 of the diagram (Figure 21) at minimum with the values in the lower dynamic range provided in Table 22.
After a flush time T1 or T4 in Table 22, the measured flow rate shall be at least the significant flush flow rate (Qs). The measured flow rate may fall below the significant flush flow rate (Qs) after point M of the diagram (Figure 21).
The flush water volume shall not be less than 6 l and shall not exceed 6,6 l.
The flush times shall be evaluated in accordance with Table 22, depending on the valve design type.
• Class 9 - WC flushing valves (intended for the release of 9 l):
The flush flow rate (Qmin) shall correspond at Point H/H1 of the diagram (Figure 21) at minimum with the values in the lower dynamic range provided in Table 22.
After a flush time T2 or T5 in Table 22, the measured flow rate shall be at least the significant flush flow rate (Qs). The measured flow rate may fall below the significant flush flow rate (Qs) after point M of the diagram (Figure 21).
The flush water volume shall not be less than 9 l and shall not exceed 9,9 l.
The flush times shall be evaluated in accordance with Table 22, depending on the valve design type.
7.5.4.3 Requirements for WC flushing valves DN 25 and DN 32
For a set dynamic pressure of (0,08+ 0,005) MPa ((0,8+ 0,05) bar), the flush flow rate, flush water volume and flush time shall correspond with the following requirements.
• Class 6 -WC flushing valves (intended for the release of 6 l or 6 l to 9 l):
The flush flow rate (Qmin) shall correspond at Point H/H1 of the diagram (Figure 21) at minimum with the values in the lower dynamic range provided in Table 22.
After a flush time T1 or T4 in Table 22, the measured flow rate shall be at least the significant flush flow rate (Qs). The measured flow rate may fall below the significant flush flow rate (Qs) after point M of the diagram (Figure 21).
The flush water volume shall not be less than 6 l and shall not exceed 6,6 l.
The flush times shall be evaluated in accordance with Table 22, depending on the valve design type.
• Class 9 - WC flushing valves (intended for the release of 9 l):
The flush flow rate (Qmin) shall correspond at Point H/H1 of the diagram (Figure 21) at minimum with the values in the lower dynamic range provided in Table 22.
After a flush time T2 or T5 in Table 22, the measured flow rate shall be at least the significant flush flow rate (Qs). The measured flow rate may fall below the significant flush flow rate (Qs) after point M of the diagram (Figure 21).
The flush water volume shall not be less than 9 l and shall not exceed 9,9 l.
The flush times shall be evaluated in accordance with Table 22, depending on the valve design type.
#### 7.5.5 在较高动压下测试冲洗流量/冲击力 Testing of flush flow rate / impact force at upper dynamic pressure
7.5.5.1 Procedure
The procedure takes place in accordance with 7.5.2.3.
7.5.5.2 Requirements for WC flushing valves DN 20
For a set dynamic pressure of (0,4– 0,001) MPa ((4– 0,1) bar), the maximum flush flow rate (Qmax) shall not exceed the values in the upper dynamic pressure range provided in Table 22, depending on the valve design type.
7.5.5.3 Requirements for WC flushing valves DN 25 and DN 32
For a set dynamic pressure of (0,25– 0,001) MPa ((2,5– 0,1) bar) for DN 25 and of (0,2– 0,001) MPa ((2– 0,1) bar) for DN 32, the maximum flush flow rate (Qmax) shall not exceed the values in the upper dynamic pressure range provided in Table 22, depending on the valve design type.
Table 22 — Summary of the requirements for servo-controlled hydraulic flushing valves
7.5.6 水锤的测量 Measurement of water hammer
7.5.6.1 Procedure
The test shall be performed in accordance with EN 12541:2002, 10.5.1 “Test method”.
The test takes place in the upper dynamic pressure range, in accordance with Table 22.
The tapware is adjusted, in accordance with 7.5.2.3 for DN 20 and 7.5.2.4 for DN 25 and 32.
7.5.6.2 Requirements
The difference ΔP between the maximum pressure recorded during the closure and the static rest pressure after closure shall not exceed 0,3 MPa (3 bar).