Valve¶

Create Function¶

For creating a single valve:

create_valve(net, from_junction, to_junction, diameter_m, opened=True, loss_coefficient=0, name=None, index=None, type='valve', **kwargs)¶

Creates a valve element in net[“valve”] from valve parameters.

Parameters

net (pandapipesNet) – The net for which this valve should be created
from_junction (int) – ID of the junction on one side which the valve will be connected with
to_junction (int) – ID of the junction on the other side which the valve will be connected with
diameter_m (float) – The valve diameter in [m]
opened (bool, default True) – Flag to show if the valve is opened and allows for fluid flow or if it is closed to block the fluid flow.
loss_coefficient (float, default 0) – The pressure loss coefficient introduced by the valve shape
name (str, default None) – A name tag for this valve
index (int, default None) – Force a specified ID if it is available. If None, the index one higher than the highest already existing index is selected.
type (str, default None) – An identifier for special types of valves
kwargs – Additional keyword arguments will be added as further columns to the net[“valve”] table

Returns

index - The unique ID of the created element

Return type

int

Example

>>> create_valve(net, 0, 1, diameter_m=4e-3, name="valve1")

For creating multiple valves at once:

create_valves(net, from_junctions, to_junctions, diameter_m, opened=True, loss_coefficient=0, name=None, index=None, type='valve', **kwargs)¶

Convenience function for creating many pipes at once. Parameters ‘from_junctions’ and ‘to_junctions’ must be arrays of equal length. Other parameters may be either arrays of the same length or single values.

Parameters

net (pandapipesNet) – The net for which this valve should be created
from_junctions (Iterable(int)) – IDs of the junctions on one side which the valves will be connected to
to_junctions (Iterable(int)) – IDs of the junctions on the other side to which the valves will be connected to
diameter_m (Iterable or float) – The valve diameters in [m]
opened (Iterable or bool, default True) – Flag to show if the valves are opened and allow for fluid flow or if they are closed to block the fluid flow.
loss_coefficient (Iterable or float, default 0) – The pressure loss coefficients introduced by the valve shapes
name (Iterable or str, default None) – Name tags for the valves
index (Iterable(int), default None) – Force specified IDs if they are available. If None, the index one higher than the highest already existing index is selected and counted onwards.
type (Iterable or str, default "valve") – Identifiers for special types of valves (e.g. below or above ground)
kwargs – Additional keyword arguments will be added as further columns to the net[“valve”] table

Returns

index - The unique IDs of the created elements

Return type

array(int)

Example

>>> create_valves(net, from_junctions=[0, 1, 4], to_junctions=[1, 5, 6],                 opened=[True, False, True], diameter_m=4e-3, name=["valve_%d" for d in range(3)])

Component Table Data¶

net.valve

Parameter	Datatype	Value Range	Explanation
name	string		Name of the valve
from_junction	integer	\(>\) 0	Index of junction at which the valve starts
to_junction	integer	\(>\) 0	Index of junction at which the valve ends
diameter_m	float	\(\gt\) 0	Inner diameter of the pipe [m]
opened	boolean	True / False	Indicates if the valve is opened
loss_coefficient	float	\(\geq\) 0	An additional pressure loss coefficient
type	string		Type variable to classify junctions

Physical Model¶

A valve is an edge component which can be used to connect or disconnect network sections. The valve can be modelled as ideal component, which is either fully open or closed causing no losses. However, a pressure loss coefficient can be imposed as well. This property considers a specific loss caused by the component when opened and models internal pressure losses. There are no losses when the component is closed.

The valve is considered as branch element with no length and is modelled accordingly.

Result Table Data¶

For incompressible media:

net.res_valve

Parameter	Datatype	Explanation
v_mean_m_per_s	float	The mean valve velocity [m/s]
p_from_bar	float	Pressure at “from”-junction [bar]
p_to_bar	float	Pressure at “to”-junction [bar]
t_from_k	float	Temperature at “from”-junction [K]
t_to_k	float	Temperature at “to”-junction [K]
mdot_from_kg_per_s	float	Mass flow into valve [kg/s]
mdot_to_kg_per_s	float	Mass flow out of valve [kg/s]
vdot_norm_m3_per_s	float	Norm volume flow [m^3/s]

For compressible media:

net.res_valve

Parameter	Datatype	Explanation
v_from_m_per_s	float	The velocity at the valve entry [m/s]
v_to_m_per_s	float	The velocity at the valve exit [m/s]
v_mean_m_per_s	float	The mean valve velocity [m/s]
p_from_bar	float	Pressure at “from”-junction [bar]
p_to_bar	float	Pressure at “to”-junction [bar]
t_from_k	float	Temperature at “from”-junction [K]
t_to_k	float	Temperature at “to”-junction [K]
mdot_from_kg_per_s	float	Mass flow into valve [kg/s]
mdot_to_kg_per_s	float	Mass flow out of valve [kg/s]
vdot_norm_m3_per_s	float	Norm volume flow [m^3/s]
reynolds	float	Average Reynolds number
lambda	float	Average valve friction factor
normfactor_from	float	Normfactor to calculate real gas velocity at “from”-junction (only for gas flows)
normfactor_to	float	Normfactor to calculate real gas velocity at “to”-junction (only for gas flows)