Equivalent Length of Common Fittings
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Transcript of Equivalent Length of Common Fittings
Equivalent length of common fittings like
• elbows - regular 90o, long radius 90
o, regular 45
o
• tees - line flow and branch flow
• return bends - regular and long radius
• valves - globe, gate, angle and swing check
• strainers
in hot water piping systems are indicated in the tables below.
Screwed Fittings - equivalent length in feet
Equivalent length (in feet) of straight pipe for fittings like bends, returns, tees and valves.
Screwed Fittings - equivalent length in meter
Equivalent length (in meters) of straight pipe for fittings like bends, returns, tees and valves.
Flanged Fittings - equivalent length in feet
Equivalent length (in feet) of straight pipe for fittings like bends, returns, tees and valves.
Flanged Fittings - equivalent length in meter
Equivalent length (in meters) of straight pipe for fittings like bends, returns, tees and valves.
PUMP CALCULATIONS
1 DATA REQUIRED
SERVICE
% SOLID CONTENTS
DENSITY Kg/M3
VISCOSITY Cp
FLOW M3/Hr
PUMPING TEMPERATURE
VAPOUR PRESSURE AT PUMPING TEMPERATURE mmHgabs
SUCTION LINE SIZE ID mm : di
DISCHARGE LINE SIZE ID mm : Di
2 SUCTION PRESSURE CALCULATIONS
PRESSURE ABOVE THE LIQUID SURFACE M wc
VERTICAL STATIC HEIGHT M wc
TOTAL STRAIGHT LENGTH M : A
2.1 EQUIVALENT LENGTH OF PIPE FITTINGS : B
BALL VALVE
STRAINER
90o BEND
TOTAL EQUIVALENT LENGTH (A + B) M
2.2 FRICTIONAL PRESSURE DROP
VELOCITY M/sec FLOW ( M3/Hr)
(CROSS SECTIONAL AREA OF PIPE) x 3600
REYNOLD NO di x u x density
viscosity
LAMINAR FLOW : Re < 2200, TURBULENT FLOW: Re > 2200
FRICTION FACTOR : f
FOR LAMINAR FLOW
f = 16 / Re
FOR TUBULENT FLOW
f = 0.0035 + 0.264 / ( Re ^ 0.42 )
FRICTIONAL PRESSURE DROP = 4 x f x ( L/di) x ( Density x u ^ 2 / 2 x g )
2.3 SUCTION HEAD(PRESSURE)abs= Pressure above liquid surface + / - static height - frictional pressure drop
2.4 NPSH available = SUCTION HEAD - VAPOUR PRESSURE at pumping temperature
3 DISCHARGE PRESSURE CALCULATIONS
PRESSURE ABOVE THE LIQUID SURFACE M wc
VERTICAL STATIC HEIGHT M wc
TOTAL STRAIGHT LENGTH M : A
3.1 EQUIVALENT LENGTH OF PIPE FITTINGS : B
BALL VALVE
GATE VALVE
CHECK VALVE
90o BENDS ETC
TOTAL EQUIVALENT LENGTH (A + B) M
3.2 FRICTIONAL PRESSURE DROP
VELOCITY M/sec FLOW ( M3/Hr)
(CROSS SECTIONAL AREA OF PIPE) x 3600
REYNOLD NO di x u x density
viscosity
LAMINAR FLOW : Re < 2200, TURBULENT FLOW: Re > 2200
FRICTION FACTOR : f
FOR LAMINAR FLOW
f = 16 / Re
FOR TUBULENT FLOW
f = 0.0035 + 0.264 / ( Re ^ 0.42 )
FRICTIONAL PRESSURE DROP = 4 x f x ( L/Di) x ( Density x u ^ 2 / 2 x g )
3.3 EQUIPMENT PRESSURE DROPS
HEAT EXCHANGER
OTHERS
3.4 INSTRUMENT PRESSURE DROPS
CONTROL VALVE
FLOW METER/ROTAMETER
ORIFICE Etc
3.5 DISCHARGE HEAD ( PRESSURE)abs = Pressure above liquid surface + static height + frictional pressure drop f
+ Equipment pressure drop + Instrument pressure drop