def Reynolds(Q, G, mu, A):
# convert Q from m3/s to lpm
_Q = unitConvert(Q, 'flow', 'm3/s', 'lpm')
# convert Viscosity from Pa.s to cP
_mu = unitConvert(mu, 'dynViscosity', 'Pa.s', 'cP')
# convert Area from m2 to mm2
_A = unitConvert(A, 'area', 'm2', 'mm2')
R = _Q * (18800 * G) / (_mu * pow(_A, 0.5))
return R
def calculate(doc_original):
doc = deepcopy(doc_original)
treeUnitConvert(doc, doc['units'], SI_UNITS)
doc['errors'] = []
convert = doc['input']['convert']['_val']
if (convert == 'nu2mu'):
nu = float(doc['input']['nu']['_val'])
rho = float(doc['input']['rho']['_val'])
mu = kin2dynVisc(nu, rho)
ssu = ""
elif (convert == 'nu2ssu'):
nu = float(doc['input']['nu']['_val'])
nu_cSt = unitConvert(nu, 'kinViscosity', 'm2/s', 'cSt')
ssu = cSt2SSU(nu_cSt)
mu = ""
elif (convert == 'mu2nu'):
mu = float(doc['input']['mu']['_val'])
rho = float(doc['input']['rho']['_val'])
nu = dyn2kinVisc(mu, rho)
nu_cSt = unitConvert(nu, 'kinViscosity', 'm2/s', 'cSt')
ssu = cSt2SSU(nu_cSt)
elif (convert == 'mu2ssu'):
mu = float(doc['input']['mu']['_val'])
rho = float(doc['input']['rho']['_val'])
nu = dyn2kinVisc(mu, rho)
nu_cSt = unitConvert(nu, 'kinViscosity', 'm2/s', 'cSt')
ssu = cSt2SSU(nu_cSt)
elif (convert == 'ssu2nu'):
ssu = float(doc['input']['ssu']['_val'])
nu_cSt = SSU2cSt(ssu)
nu = unitConvert(nu_cSt, 'kinViscosity', 'cSt', 'm2/s')
mu = ""
elif (convert == 'ssu2mu'):
ssu = float(doc['input']['ssu']['_val'])
rho = float(doc['input']['rho']['_val'])
nu_cSt = SSU2cSt(ssu)
nu = unitConvert(nu_cSt, 'kinViscosity', 'cSt', 'm2/s')
mu = kin2dynVisc(nu, rho)
nu = roundit(nu)
mu = roundit(mu)
ssu = roundit(ssu)
doc['result'].update({'nu': {'_val': str(nu), '_dim': 'kinViscosity'}})
doc['result'].update({'mu': {'_val': str(mu), '_dim': 'dynViscosity'}})
doc['result'].update({'ssu': {'_val': str(ssu)}})
treeUnitConvert(doc, SI_UNITS, doc['units'], autoRoundOff=True)
doc_original['result'].update(doc['result'])
doc_original['errors'] = doc['errors']
return True
def API520_A_l_cert(Q, G, P, Pb, Kd=0.65, Kw=1, Kc=1, Kv=1):
# convert Q from m3/s to lpm
_Q = unitConvert(Q, 'flow', 'm3/s', 'lpm')
# convert P from SI Pa to kPa
_P = unitConvert(P, 'pressure', 'Pa', 'kPa')
# convert Pb from SI Pa to kPa
_Pb = unitConvert(Pb, 'pressure', 'Pa', 'kPa')
B = pow(G / (_P - _Pb), 0.5)
_A = 11.78 * _Q * B / (Kd * Kw * Kc * Kv)
# convert P from SI Pa to kPa
A = unitConvert(_A, 'area', 'mm2', 'm2')
return A
def viscCorr(Qbep, Hbep, nu, N, Qratio):
'''
Hydraulic Institute Viscosity Correction.
'''
_Qbep = Qbep * 3600
_Hbep = Hbep
_nu = unitConvert(nu, 'kinViscosity', 'm2/s', 'cSt')
_N = N
B = 16.5 * (pow(_nu, 0.5) * pow(_Hbep, 0.0625)) / (pow(_Qbep, 0.375) *
pow(_N, 0.25))
if (B <= 1):
Cq = 1
Ch = 1
Ceta = 1
elif (B > 1 and B < 40):
f = log10(B)
k = -0.165 * pow(f, 3.15)
Cq = pow(2.71, k)
Cbep_h = Cq
Ch = 1 - (1 - Cbep_h) * pow(Qratio, 0.75)
a = -0.0547 * pow(B, 0.69)
Ceta = pow(B, a)
else:
raise Exception('Outside Correction Range')
return Cq, Ch, Ceta
def viscSel(Qvis, Hvis, nu):
_Qvis = Qvis * 3600
_Hvis = Hvis
_nu = unitConvert(nu, 'kinViscosity', 'm2/s', 'cSt')
B = 2.80 * (pow(_nu, 0.5) / (pow(_Qvis, 0.25) * pow(_Hvis, 0.125)))
if (B <= 1):
Cq = 1
Ch = 1
Ceta = 1
elif (B > 1 and B < 40):
f = log10(B)
k = -0.165 * pow(f, 3.15)
Cq = pow(2.71, k)
Ch = Cq
a = -0.0547 * pow(B, 0.69)
Ceta = pow(B, a)
else:
raise Exception('Outside Correction Range')
return Cq, Ch, Ceta
def calculate(doc_original):
doc = deepcopy(doc_original)
treeUnitConvert(doc, doc['units'], SI_UNITS)
doc['errors'] = []
Pset = float(doc['input']['Pset']['_val'])
Pover = float(doc['input']['Pover']['_val'])
Psuper = float(doc['input']['Psuper']['_val'])
Pbuiltup = float(doc['input']['Pbuiltup']['_val'])
Psuper_is_const = doc['input']['Psuper_is_const']['_val']
Q = float(doc['input']['Q']['_val'])
rho = float(doc['input']['rho']['_val'])
viscosity_basis = doc['input']['viscosity_basis']['_val']
valve_design = doc['input']['valve_design']['_val']
rupture_disc = doc['input']['rupture_disc']['_val']
Kd_basis = doc['input']['Kd_basis']['_val']
Kw_basis = doc['input']['Kw_basis']['_val']
Kc_basis = doc['input']['Kc_basis']['_val']
if (viscosity_basis == 'Dynamic'):
mu = float(doc['input']['mu']['_val'])
if (viscosity_basis == 'Kinematic'):
nu = float(doc['input']['nu']['_val'])
mu = kin2dynVisc(nu, rho)
if (viscosity_basis == 'SSU'):
ssu = float(doc['input']['ssu']['_val'])
nu_cst = SSU2cSt(ssu)
nu = unitConvert(nu_cst, 'kinViscosity', 'cSt', 'm2/s')
mu = kin2dynVisc(nu, rho)
Patm = 101325 # atmospheric pressure
P = Pset + (Pover / 100) * Pset + Patm # relieving pressure
Pback = Psuper + Pbuiltup
if (Psuper_is_const == 'Yes'):
Psuper_variable = 0
else:
Psuper_variable = Psuper
valve_design_remark = ""
if (valve_design == 'Conventional'):
Puncompensated = Psuper_variable + Pbuiltup
allowable_overpressure = Pset * (Pover / 100)
if (Puncompensated > allowable_overpressure):
valve_design_remark = 'Not acceptable. Uncompensated backpressure exceeds allowable overpressure'
else:
if (Pback > allowable_overpressure):
valve_design_remark = 'Acceptable, subject to compensation of constant superimposed back pressure'
else:
valve_design_remark = 'Acceptable'
if (valve_design == 'Balanced'):
Pback_max = 0.5 * Pset
if (Pback > Pback_max):
valve_design_remark = 'Not Acceptable. Total backpressure exceeds 50% of set pressure'
else:
valve_design_remark = 'Acceptable'
if (valve_design == 'Pilot-Operated'):
valve_design_remark = 'Acceptable'
if (Kd_basis == 'Manual'):
Kd = float(doc['input']['Kd_manual']['_val'])
else:
Kd = 0.65
if (rupture_disc == 'No'):
Kc = 1
else:
if (Kc_basis == 'Manual'):
Kc = float(doc['input']['Kc_manual']['_val'])
else:
Kc = 0.9
G = rho / 1000
Pb = Pback + Patm
Pset_abs = Pset + Patm
if (valve_design == 'Balanced'):
if (Kw_basis == 'Manual'):
Kw = float(doc['input']['Kw_manual']['_val'])
else:
try:
Kw = API520_W(Pset_abs, Pb)
Kw = roundit(Kw)
except Exception as e:
Kw = math.nan
doc["errors"].append(str(e))
doc["errors"].append(
"Failed to calculated, backpressure. Provide Manual input using manufacturer data"
)
else:
Kw = 1
Kv = 1
try:
while True:
A = API520_A_l_cert(Q=Q,
G=G,
P=P,
Pb=Pb,
Kd=Kd,
Kw=Kw,
Kc=Kc,
Kv=Kv)
print(A)
A_sel = API520_round_size(A)
R = Reynolds(Q, G, mu, A_sel)
Kv = API520_Kv(R)
Kv = roundit(Kv)
A = A / Kv
if (A_sel >= A):
break
A_letter = API526_letter(A_sel)
except Exception:
A = math.nan
A_sel = math.nan
Kv = math.nan
R = math.nan
A_letter = ""
doc['errors'].append(
"Failed to calculate discharge Area (A). Check Inputs")
doc['result'].update(
{'valve_design_remark': {
'_val': str(valve_design_remark)
}})
doc['result'].update({'R': {'_val': str(R)}})
doc['result'].update({'Kd': {'_val': str(Kd)}})
doc['result'].update({'Kw': {'_val': str(Kw)}})
doc['result'].update({'Kc': {'_val': str(Kc)}})
doc['result'].update({'Kv': {'_val': str(Kv)}})
doc['result'].update({'A': {'_val': str(A), '_dim': 'area'}})
doc['result'].update({'A_sel': {'_val': str(A_sel), '_dim': 'area'}})
doc['result'].update({'A_letter': {'_val': str(A_letter)}})
treeUnitConvert(doc, SI_UNITS, doc['units'], autoRoundOff=True)
doc_original['result'].update(doc['result'])
doc_original['errors'] = doc['errors']
return True