# Pressure Drop Of A Straight Pipe

The following formula is used to calculate pressure drop, due to straight lengths

Δp1 =ΣR • l

where:

R is the unitary pressure drop expressed in mbar or in
Pa/m
l is the straight pipe length in m

As well, the following formula is used to calculate the unitary pressure drop:

R = λ xρ x v2÷2 x d

where:
λ is the pipe friction coefficient
ρ is the fluid density expressed in kg/m3
v is the fluid speed expressed in m/s
d is the internal pipe diameter in mm

For a practical calculation of pressure drops it is possible to refer to the following tables.

Pressure Drop of Single Localised Resistances

The following formula is used to calculate pressure drops due to single localised resistances.

Δp2 = ΣZ

where:
Z is the pressure drop of the single fitting expressed in mbar

As well, the following formula is used to calculate the pressure drop of
the single fitting

Z = ξ xρ x v2÷2

where:
ξ is the coefficient, which depends on the fitting type
ρ is the fluid density expressed in Kg/m3
v is the fluid speed expressed in m/s

The following formula is used to calculate pressure drop, due to straight lengths

Δp1 =ΣR • l

where:

R is the unitary pressure drop expressed in mbar or in
Pa/m
l is the straight pipe length in m

As well, the following formula is used to calculate the unitary pressure drop:

R = λ xρ x v2÷2 x d

where:
λ is the pipe friction coefficient
ρ is the fluid density expressed in kg/m3
v is the fluid speed expressed in m/s
d is the internal pipe diameter in mm

For a practical calculation of pressure drops it is possible to refer to the following tables.

Pressure Drop of Single Localised Resistances

The following formula is used to calculate pressure drops due to single localised resistances.

Δp2 = ΣZ

where:
Z is the pressure drop of the single fitting expressed in mbar

As well, the following formula is used to calculate the pressure drop of
the single fitting

Z = ξ xρ x v2÷2

where:
ξ is the coefficient, which depends on the fitting type
ρ is the fluid density expressed in Kg/m3
v is the fluid speed expressed in m/s