CV_NOISE_LIQ_2015

This function predicts hydrodynamic control-valve noise for liquid service using the IEC 60534-8-4 (2015) method. It returns the A-weighted sound pressure level at 1 m downstream of the valve, using operating pressures, liquid properties, valve capacity, and pipe/acoustic parameters.

Sound level is represented on a logarithmic decibel scale:

L_p = 20\log_{10}\left(\frac{p_{\mathrm{rms}}}{p_0}\right)

with reference pressure p_0=2\times10^{-5} Pa. The optional cavitation sensitivity factor x_{Fz} can be supplied directly when available.

Excel Usage

=CV_NOISE_LIQ_2015(m, p_in, p_out, psat, rho, c, kv, d, di, fl, fd, t_pipe, rho_pipe, c_pipe, rho_air, c_air, xfz, an)

m (float, required): Mass flow rate of liquid through the control valve (kg/s)
p_in (float, required): Inlet pressure of the fluid before valves and reducers (Pa)
p_out (float, required): Outlet pressure of the fluid after valves and reducers (Pa)
psat (float, required): Saturation pressure of the fluid at inlet temperature (Pa)
rho (float, required): Density of the liquid at the inlet (kg/m^3)
c (float, required): Speed of sound of the liquid at the inlet conditions (m/s)
kv (float, required): Metric Kv valve flow coefficient (m^3/hr)
d (float, required): Diameter of the valve (m)
di (float, required): Internal diameter of the pipe before and after the valve (m)
fl (float, required): Liquid pressure recovery factor (-)
fd (float, required): Valve style modifier (-)
t_pipe (float, required): Wall thickness of the pipe after the valve (m)
rho_pipe (float, optional, default: 7800): Density of the pipe wall material at flowing conditions (kg/m^3)
c_pipe (float, optional, default: 5000): Speed of sound of the pipe wall material at flowing conditions (m/s)
rho_air (float, optional, default: 1.293): Density of the air surrounding the valve and pipe wall (kg/m^3)
c_air (float, optional, default: 343): Speed of sound of the air surrounding the valve and pipe wall (m/s)
xfz (float, optional, default: null): If specified, this value is used instead of estimated (-)
an (float, optional, default: -4.6): Valve correction factor for acoustic efficiency (-)

Returns (float): A-weighted sound pressure level at 1 meter (dB), or an error message (str) if input is invalid.

Example 1: Basic noise calculation with default parameters

Inputs:

m	p_in	p_out	psat	rho	c	kv	d	di	fl	fd	t_pipe	rho_pipe	c_pipe	rho_air	c_air	an
40	1000000	650000	2320	997	1400	77.848	0.1	0.1071	0.92	0.42	0.0036	7800	5000	1.293	343	-4.6

Excel formula:

=CV_NOISE_LIQ_2015(40, 1000000, 650000, 2320, 997, 1400, 77.848, 0.1, 0.1071, 0.92, 0.42, 0.0036, 7800, 5000, 1.293, 343, -4.6)

Expected output:

81.582

Example 2: Noise calculation with specified xFz value

Inputs:

m	p_in	p_out	psat	rho	c	kv	d	di	fl	fd	t_pipe	xfz
50	1500000	850000	3200	995	1350	90	0.12	0.127	0.88	0.38	0.004	0.05

Excel formula:

=CV_NOISE_LIQ_2015(50, 1500000, 850000, 3200, 995, 1350, 90, 0.12, 0.127, 0.88, 0.38, 0.004, 0.05)

Expected output:

117.24

Example 3: Noise calculation with different An correction factor

Inputs:

m	p_in	p_out	psat	rho	c	kv	d	di	fl	fd	t_pipe	an
30	1200000	720000	2500	1000	1450	65	0.08	0.0889	0.9	0.4	0.003	-4

Excel formula:

=CV_NOISE_LIQ_2015(30, 1200000, 720000, 2500, 1000, 1450, 65, 0.08, 0.0889, 0.9, 0.4, 0.003, -4)

Expected output:

92.1424

Example 4: Noise calculation with only required parameters

Inputs:

m	p_in	p_out	psat	rho	c	kv	d	di	fl	fd	t_pipe
25	1000000	700000	2000	998	1420	55	0.09	0.095	0.85	0.45	0.0035

Excel formula:

=CV_NOISE_LIQ_2015(25, 1000000, 700000, 2000, 998, 1420, 55, 0.09, 0.095, 0.85, 0.45, 0.0035)

Expected output:

72.6988

Python Code

Show Code

from fluids.control_valve import control_valve_noise_l_2015 as fluids_control_valve_noise_l_2015
import math

def cv_noise_liq_2015(m, p_in, p_out, psat, rho, c, kv, d, di, fl, fd, t_pipe, rho_pipe=7800, c_pipe=5000, rho_air=1.293, c_air=343, xfz=None, an=-4.6):
    """
    Calculates the sound made by a liquid flowing through a control valve according to the standard IEC 60534-8-4 (2015) using fluids.control_valve.control_valve_noise_l_2015.

    See: https://fluids.readthedocs.io/fluids.control_valve.html#fluids.control_valve.control_valve_noise_l_2015

    This example function is provided as-is without any representation of accuracy.

    Args:
        m (float): Mass flow rate of liquid through the control valve (kg/s)
        p_in (float): Inlet pressure of the fluid before valves and reducers (Pa)
        p_out (float): Outlet pressure of the fluid after valves and reducers (Pa)
        psat (float): Saturation pressure of the fluid at inlet temperature (Pa)
        rho (float): Density of the liquid at the inlet (kg/m^3)
        c (float): Speed of sound of the liquid at the inlet conditions (m/s)
        kv (float): Metric Kv valve flow coefficient (m^3/hr)
        d (float): Diameter of the valve (m)
        di (float): Internal diameter of the pipe before and after the valve (m)
        fl (float): Liquid pressure recovery factor (-)
        fd (float): Valve style modifier (-)
        t_pipe (float): Wall thickness of the pipe after the valve (m)
        rho_pipe (float, optional): Density of the pipe wall material at flowing conditions (kg/m^3) Default is 7800.
        c_pipe (float, optional): Speed of sound of the pipe wall material at flowing conditions (m/s) Default is 5000.
        rho_air (float, optional): Density of the air surrounding the valve and pipe wall (kg/m^3) Default is 1.293.
        c_air (float, optional): Speed of sound of the air surrounding the valve and pipe wall (m/s) Default is 343.
        xfz (float, optional): If specified, this value is used instead of estimated (-) Default is None.
        an (float, optional): Valve correction factor for acoustic efficiency (-) Default is -4.6.

    Returns:
        float: A-weighted sound pressure level at 1 meter (dB), or an error message (str) if input is invalid.
    """
    try:

      # Validate and convert input parameters to float
      try:
        m = float(m)
        p_in = float(p_in)
        p_out = float(p_out)
        psat = float(psat)
        rho = float(rho)
        c = float(c)
        kv = float(kv)
        d = float(d)
        di = float(di)
        fl = float(fl)
        fd = float(fd)
        t_pipe = float(t_pipe)
        rho_pipe = float(rho_pipe)
        c_pipe = float(c_pipe)
        rho_air = float(rho_air)
        c_air = float(c_air)
        if xfz is not None:
          xfz = float(xfz)
        an = float(an)
      except (TypeError, ValueError):
        return "Error: All parameters must be numeric values."

      # Check for non-finite values
      values = [m, p_in, p_out, psat, rho, c, kv, d, di, fl, fd, t_pipe, rho_pipe, c_pipe, rho_air, c_air, an]
      if xfz is not None:
        values.append(xfz)
      if any(not math.isfinite(v) for v in values):
        return "Error: All parameters must be finite numbers."

      # Call the fluids package implementation
      try:
        result = fluids_control_valve_noise_l_2015(
          m=m,
          P1=p_in,
          P2=p_out,
          Psat=psat,
          rho=rho,
          c=c,
          Kv=kv,
          d=d,
          Di=di,
          FL=fl,
          Fd=fd,
          t_pipe=t_pipe,
          rho_pipe=rho_pipe,
          c_pipe=c_pipe,
          rho_air=rho_air,
          c_air=c_air,
          xFz=xfz,
          An=an
        )
        return result
      except Exception as exc:
        return f"Error: Failed to compute liquid noise: {exc}"
    except Exception as e:
      return f"Error: {str(e)}"

Online Calculator

m *

Mass flow rate of liquid through the control valve (kg/s)

p_in *

Inlet pressure of the fluid before valves and reducers (Pa)

p_out *

Outlet pressure of the fluid after valves and reducers (Pa)

psat *

Saturation pressure of the fluid at inlet temperature (Pa)

rho *

Density of the liquid at the inlet (kg/m^3)

c *

Speed of sound of the liquid at the inlet conditions (m/s)

kv *

Metric Kv valve flow coefficient (m^3/hr)

d *

Diameter of the valve (m)

di *

Internal diameter of the pipe before and after the valve (m)

fl *

Liquid pressure recovery factor (-)

fd *

Valve style modifier (-)

t_pipe *

Wall thickness of the pipe after the valve (m)

rho_pipe

Density of the pipe wall material at flowing conditions (kg/m^3)

c_pipe

Speed of sound of the pipe wall material at flowing conditions (m/s)

rho_air

Density of the air surrounding the valve and pipe wall (kg/m^3)

c_air

Speed of sound of the air surrounding the valve and pipe wall (m/s)

xfz

If specified, this value is used instead of estimated (-)

Valve correction factor for acoustic efficiency (-)