dP Pressure Drop

Reference Values

Equivalent lengths

Bends/Tees
180 bend, R=5D 28
90 bend, R=5D 16
90 bend (square , R=1.5D) 20
45 bend(square , R=1.5D) 16
Tee (flow straight through) 20
Tee (flow through side outlet) 65
Gates/Valves
Gate valve open 13
-closed 39
-closed 195
-closed 300
Membrane valve 200
Ball valve (spherical plug valve) 18
Needle valve 1000
Butterfly valve (larger then 6 inch) 20
Globe valve 300
Nozzle (suction nozzle on vessel) 32
Check valve (in-line ball type) 150
Check valve (swing type) 135
Filter (Y-type and bucket type) 250

Surface roughness value [E]

various materials  
Glass 0.015
Lead 0.015
Copper 0.015
Brass 0.015
Steel Pipe  
new 0.04
After longer use 0.2
Slightly rusted 0.4
Very rusted 3.35
galvanised 0.15
Cast iron  
New 0.5
With bitumen layer 0.2
Slightly rusted 1.5
Very rusted 3.0

Formulae

The user makes a selection of materials and it's reference values are then substituted in the formulae