Resistance coefficient K calculator

flow through valves and fittings

online since 2010

pipe flow calculator

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resistance factor K for flow in valves and fittings
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Calculator description

You can use the calculator for resistance coefficient (or resistance factor) K calculation for flow through valves and fittings.

Resistance coefficient K is proportional coefficient between pressure drop (head loss) and square velocity of fluid flowing through valves and fittings like an elbow, bend, reducer, tee, pipe entrance, pipe exit or valve.

With the resistance coefficient, K calculated, you can compute equivalent length l/d with pressure drop calculator, afterwards.

Resistance coefficient should be used with pressure drop calculator or with gas compressible flow calculator to calculate pressure drop in the piping system that includes obstructions like fittings and valves.

The pressure loss due to resistance in valves and fittings are in a direct relationship with the diameter on which velocity occurs.

Based on the size and shape of valves and fittings different values for resistance coefficient are computed.

Fittings and valves

Calculator includes flow resistance calculation for following fittings and valves:

  • 90 deg elbow and pipe bend
  • return bend
  • standard elbow
  • mitre bend
  • standard tee
  • pipe entrance
  • pipe exit
  • sudden and gradual enlargement
  • sudden and gradual contraction
  • gate full bore valve
  • gate reduced bore valve
  • globe valve
  • swing check angled valve
  • swing check valve
  • lift check valve
  • tilting disk check valve
  • stop check valve
  • stop check angled valve
  • ball valve
  • butterfly valve
  • foot poppet valve
  • foot hinged valve
  • plug straight valve
  • three way valve

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