Siemens 7ML19985AB01 Manuel D’Utilisation
BS-3680 Round Nose Horizontal Crest Weir, P3 = 2
‘U’ parameters required *
‘U’ parameters calculated **
U0 = crest width
b
U3 = Cv
U1 = crest height
p
U4 = Cd
U2 = crest length
L
U5 = A
*
obtain from manufacturer’s specifications.
**
calculated by OCM-3. May be viewed by accessing ‘U’ parameter.
Reference
ABSOLUTE CALCULATION, P4 = 0
¤
For flows that can be calculated by the equation:
q = (2/3)
1.5
x g
0.5
x Cv x Cs x Cd x b x h
1.5
where :
q = flow rate
Cv = velocity coefficient
g = gravitational acceleration
Cs = shape coefficient
b = throat width
Cd = discharge coefficient
h = head
RATIOMETRIC CALCULATION, P4 = 1
¤
For flows that can be calculated by the equation:
q = q
cal
x Cd/Cd
cal
x Cv/Cv
cal
x (h/h
cal
)
1.5
where :
q = flow rate
q
cal
= flow rate at maximum head
h = head
h
cal
= maximum head
Cv = velocity coefficient
Cv
cal
= velocity coefficient for maximum head
Cd = discharge coefficient for head
Cd
cal
= discharge coefficient for maximum head
¤
Refer to Operation \ Flow Calculation.
7ML19985AB01
OCM III
60