fixed merge conflicts

wallthick/cli.py

@@ -32,7 +32,7 @@
 @click.command()
 @click.argument('inputs', type=click.File('rb'))
 def main(inputs):
-    '''Console script for wallthick.'''
+    """Console script for wallthick."""
     data = json.load(inputs)
     if all(param in data for param in req_inputs):
         click.secho(

wallthick/pd8010.py

@@ -16,103 +16,132 @@
 
 
 def internal_pressure(P_d, P_h):
+    """Returns internal pressure [Pa] due to combined design pressure and
+    pressure head.
+
+    :param P_d: Design pressure [Pa]
+    :param P_h: Pressure head [Pa]
+    """
     return P_d + P_h
 
 
 def water_depths(h, H_t, H):
+    """Returns minimum and maximum water depths [m] as a tuple.
+
+    :param h: Water depth [m]
+    :param H_t: Tide [m]
+    :param H: Wave height [m]
+    """
     d_min = h - (H/2)
     d_max = h + H_t + (H/2)
     return d_min, d_max
 
 
 def external_pressure(rho, g, d):
+    """Returns external pressure [Pa] at water depth.
+
+    :param rho: Water density [kg/m^2]
+    :param g: Acceleration of gravity [m/s^2]
+    :param d: Water depth [m]
+    """
     return rho * g * d
 
 
 def hoop_pressure_thin(t, D_o, P_o, sig):
-    """
-    Number [Pa], Number [Pa], Number [m], Number [Pa] -> Number [m]
-
-    Returns the internal pressure that induces a stress, sig, in a thin
+    """Returns the internal pressure [Pa] that induces a stress, sig, in a thin
     wall pipe of thickness t.
 
-    Equation (3)
+    PD 8010-2 Equation (3)
+
+    :param t: Wall thickness [m]
+    :param D_o: Outside diameter [m]
+    :param P_o: External pressure [Pa]
+    :param sig: Minimum yield strength [Pa]
     """
     return ((sig * 2 * t) / D_o) + P_o
 
 
 def hoop_pressure_thick(t, D_o, P_o, sig):
-    """
-    Number [Pa], Number [Pa], Number [m], Number [Pa] -> Number [m]
-
-    Returns the internal pressure that induces a stress, sig, in a thick
+    """Returns the internal pressure [Pa] that induces a stress, sig, in a thick
     walled pipe of thickness t.
 
-    Equation (5)
+    PD 8010-2 Equation (5)
+
+    :param t: Wall thickness [m]
+    :param D_o: Outside diameter [m]
+    :param P_o: External pressure [Pa]
+    :param sig: Minimum yield strength [Pa]
     """
     return ((sig * (D_o**2 - (D_o - 2 * t)**2)) / (D_o**2 + (D_o - 2 * t)**2)) + P_o
 
 
 def hoop_thickness_thin(P_i, P_o, D_o, sig_y_d):
-    """
-    Number [Pa], Number [Pa], Number [m], Number [Pa] -> Number [m]
+    """Returns the minimum wall thickness [m] for internal pressure containment
+    for a thin walled pipe.
 
-    Returns the minimum wall thickness for internal pressure containment for a
-    thin walled pipe.
+    PD 8010-2 Equation (3)
 
-    Equation (3)
+    :param P_i: Internal pressure [Pa]
+    :param P_o: External pressure [Pa]
+    :param D_o: Outside diameter [m]
+    :param sig_y_d: Minimum yield strength [Pa]
     """
     return abs(P_i - P_o) * D_o / (2 * n_s * sig_y_d)
 
 
 def hoop_thickness_thick(P_i, P_o, D_o, sig_y_d):
-    """
-    Number [Pa], Number [Pa], Number [m], Number [Pa] -> Number [m]
+    """Returns the minimum wall thickness [m] for internal pressure containment
+    for a thick walled pipe.
 
-    Returns the minimum wall thickness for internal pressure containment for a
-    thick walled pipe.
+    PD 8010-2 Equation (5)
 
-    Equation (5)
+    :param P_i: Internal pressure [Pa]
+    :param P_o: External pressure [Pa]
+    :param D_o: Outside diameter [m]
+    :param sig_y_d: Minimum yield strength [Pa]
     """
     eq = math.sqrt((((n_s*sig_y_d - abs(P_i - P_o))) * D_o**2) /
                    (n_s*sig_y_d + abs(P_i - P_o)))
     return 0.5 * (D_o - eq)
 
 
-def hoop_thickness(P_i, P_o_min, D_o, sig_y_d):
-    """
-    Number [Pa], Number [Pa], Number [m], Number [Pa] -> Number [m]
-
-    Returns the minimum (note not nominal) wall thickness for internal pressure
-    containment.
+def hoop_thickness(P_i, P_o, D_o, sig_y_d):
+    """Returns the minimum (note not nominal) wall thickness [m] for internal
+    pressure containment.
 
     Considers:
     - Allowable hoop stress
     - Worst case maximum pressure difference
     - Appropriate wall thickness theory, i.e. thick or thin
+
+    :param P_i: Internal pressure [Pa]
+    :param P_o: External pressure [Pa]
+    :param D_o: Outside diameter [m]
+    :param sig_y_d: Minimum yield strength [Pa]
     """
-    t_min_thin = hoop_thickness_thin(P_i, P_o_min, D_o, sig_y_d)
+    t_min_thin = hoop_thickness_thin(P_i, P_o, D_o, sig_y_d)
 
     # Select appropriate wall theory based on minimum thin wall thickness
     if D_o / t_min_thin > 20:
         t_min = t_min_thin
     else:
-        t_min = hoop_thickness_thick(P_i, P_o_min, D_o, sig_y_d)
+        t_min = hoop_thickness_thick(P_i, P_o, D_o, sig_y_d)
 
     return t_min
 
 
 def req_thickness(t_min, t_corr, f_tol):
-    '''
-    Number [m], Number [m], Number [-] -> Number [m]
-
-    Returns the required wall thickness based on the following mechanical
+    """Returns the required wall thickness [m] based on the following mechanical
     allowances:
     - Corrosion allowance
     - Fabrication tolerance
 
-    Exrapolated from Equation (4)
-    '''
+    Extrapolated from Equation (4)
+
+    :param t_min: Minimum wall thickness [m]
+    :param t_corr: Corrosion allowance [m]
+    :param f_tol: Fabrication tolerance [m]
+    """
     try:
         return (t_min + t_corr) / (1 - f_tol)
     except ZeroDivisionError:
@@ -125,47 +154,47 @@ def req_thickness(t_min, t_corr, f_tol):
 
 
 def collapse_thickness(P_o, sig_y_d, E, v, D_o, f_0):
-    """
-    Number [Pa], Number [Pa], Number [Pa], Number [-], Number [m], Number [-]
-    -> Number [m]
-
-    Returns the nominal wall thickness for local buckling due to external
+    """Returns the nominal wall thickness [m] for local buckling due to external
     pressure.
 
     Considers the worst case maximum external over pressure, i.e.:
     - Minimum internal pressure (zero)
     - Maximum external pressure (at water depth, d)
 
-    (Clause G.1.2)
+    PD 8010-2 Clause G.1.2
+
+    :param P_o: External pressure [Pa]
+    :param sig_y_d: Minimum yield strength [Pa]
+    :param E: Young's modulus [Pa]
+    :param v: Poisson's ratio [-]
+    :param D_o: Outside diameter [m]
+    :param f_0: Initial ovalisation [%]
     """
 
     def P_e(t):
-        """
-        Number [m] -> Number [Pa]
+        """Returns the critical pressure [Pa] for an elastic critical tube.
 
-        Returns the critical pressure for an elastic critical tube.
+        PD 8010-2 Section G.2
 
-        Equation (G.2)
+        :param t: Wall thickness [m]
         """
         return 2 * E / (1 - v**2) * (t / D_o)**3
 
     def P_y(t):
-        """
-        Number [m] -> Number [Pa]
+        """Returns the yield pressure [Pa].
 
-        Returns the yield pressure.
+        PD 8010-2 Equation (G.3)
 
-        Equation (G.3)
+        :param t: Wall thickness [m]
         """
         return 2 * sig_y_d * (t / D_o)
 
     def char_resist(t):
-        """
-        Number [m] -> Number [Pa]
+        """Returns the characteristic resistance [m] for external pressure.
 
-        Returns the characteristic resistance for external pressure
+        PD 8010-2 Equation (G.1)
 
-        Equation (G.1)
+        :param t: Wall thickness [m]
         """
         term_1 = ((P_o / P_e(t)) - 1)
         term_2 = ((P_o / P_y(t))**2 - 1)
@@ -179,15 +208,15 @@ def char_resist(t):
 
 
 def buckle_thickness(D_o, P_p, sig_y):
-    """
-    Number [m], Number [Pa], Number [Pa] -> Number [m]
-
-    Returns the nominal buckle thickness based on the propagation pressure.
+    """Returns the nominal buckle thickness [m] based on the propagation
+    pressure. Considers the worst case maximum external pressure and ignores
+    internal pressure.
 
-    Considers the worst case maximum external pressure and ignores internal
-    pressure.
+    PD 8010-2 Equation (G.21)
 
-    Equation (G.21)
+    :param D_o: Outside diameter [m]
+    :param P_p: Propagation pressure [Pa]
+    :param sig_y: Minimum yield strength [Pa]
     """
     return D_o * (P_p / (10.7 * sig_y))**(4 / 9)
 
@@ -197,17 +226,21 @@ def buckle_thickness(D_o, P_p, sig_y):
 
 
 def strength_test_pressure(t_sel, f_tol, sig_y, D_o, P_d, P_o, P_h):
-    """
-    InputData -> Number [Pa]
-
-    Returns the strength test pressure, i.e. the minimum of:
+    """Returns the strength test pressure, i.e. the minimum of:
     - 1.5 * design pressure:
         Note that hydrostatic head is not multiplied by 1.5 (interpreted by
         last paragraph of Section 11.5.2)
     - the pressure that induces a hoop stress of 90 percent SMYS at nominal
         wall thickness.
 
-    (Section 11.5.1, Ref.1)
+    PD 8010-2 Section 11.5.1, Ref.1
+
+    :param t_sel: Selected wall thickness [m]
+    :param f_tol: fabrication tolerance [m]
+    :param sig_y: Minimum yield strength [Pa]
+    :param D_o: Outside diameter [m]
+    :param P_d: Design pressure [Pa]
+    :param P_h: Pressure head [Pa]
     """
 
     # Determine nominal wall thickness (no corrosion)
@@ -229,7 +262,11 @@ def strength_test_pressure(t_sel, f_tol, sig_y, D_o, P_d, P_o, P_h):
     return min(P_hoop, P_test)
 
 
-class Pd8010(object):
+class Pd8010:
+    """PD8010-2 Wall thickness analysis class.
+
+    :param data: Input data dictionary
+    """
 
     def __init__(self, data):
         self.t_sel = data['t_sel']
@@ -253,16 +290,23 @@ def __init__(self, data):
 
     @property
     def t_h(self):
+        """Nominal wall thickness [m] to satisfy the internal pressure (hoop)
+        criterion.
+        """
         P_i = internal_pressure(self.P_d, self.P_h)
         # min water depth
         d, _ = water_depths(self.h, self.H_t, self.H)
         P_o = external_pressure(self.rho_w, self.g, d)
+        # minimum wall thickness
         t_h_min = hoop_thickness(P_i, P_o, self.D_o, self.sig_y_d)
+        # nominal wall thickness
         return req_thickness(t_h_min, self.t_corr, self.f_tol)
 
     @property
     def t_c(self):
-        P_i = internal_pressure(self.P_d, self.P_h)
+        """Nominal wall thickness [m] to satisfy the hydrostatic collapse
+        criterion.
+        """
         # max water depth
         _, d = water_depths(self.h, self.H_t, self.H)
         # include safety factor
@@ -272,6 +316,9 @@ def t_c(self):
 
     @property
     def t_b(self):
+        """Nominal wall thickness [m] to satisfy the local buckle propagation
+        criterion.
+        """
         # max water depth
         _, d = water_depths(self.h, self.H_t, self.H)
         # propagation pressure equal to max external pressure
@@ -280,7 +327,10 @@ def t_b(self):
 
     @property
     def P_st(self):
-        ''' Strength test pressure '''
+        """Strength test pressure [Pa].
+
+        PD 8010-2 Section 11.5.2
+        """
         # min water depth
         d, _ = water_depths(self.h, self.H_t, self.H)
         P_o = external_pressure(self.rho_w, self.g, d)
@@ -289,9 +339,8 @@ def P_st(self):
 
     @property
     def P_lt(self):
-        """
-        Return leak test pressure: 1.1 * MAOP (design pressure) at LAT
+        """Leak test pressure [Pa] at LAT.
 
-        Section 11.5.3
+        PD 8010-2 Section 11.5.3
         """
         return 1.1 * self.P_d