NPSH (a) calculation

P(atm) = 1 Atm = 101325 Pa (N/m^2)P(v) = 26 mm of Hg = 3466.38 Pa (N/m^2)

ρ = Density of Fluid = 860 Kg/m^3ϒ (ρ*g) = Density * g = 8436.6

Pressure Head = P(atm)/ϒ = 12.010169974 meterElevation Head = h(e) = 2 meter

Head Losses = h(l) = 0.0252472982 meterVapour head = P(v)/ϒ = 0.4108740488 meter

NPSH (a) = 9.574048627 meter

Pressure Head The absolute pressure on the surface of the liquid in the supply tank

Elevation Head

Head Looses

• Piping and fittings act as a restriction, working against liquid as it flows towards the pump inlet.

Liquid's Vapour Head

• Typically atmospheric pressure (vented supply tank), but can be different for closed tanks. • Don’t forget that altitude affects atmospheric pressure.• Always positive (may be low, but even vacuum vessels are at a positive absolute pressure)

between the surface ofthe liquid in the supply tank and the centerline• Can be positive when liquid level is above the centerline of the pump (called static head) • Can be negative when liquid level is below the centerline of the pump (called suction lift) • Always be sure to use the lowest liquid level allowed in the tank.

Friction losses in the suction piping

of the liquid at thepumping temperature

• Must be subtracted in the end to make sure that the inlet pressure stays above the vapor pressure.• Remember, as temperature goes up, so does the vapor pressure.

Sum of Head losses of Pipes (Sheet 2), Valves (sheet 3), Bends (Sheet 4)

Values of NPSH(a) could be verified from AFT Fathom output.

The absolute pressure on the surface of the liquid in the supply tank

• Piping and fittings act as a restriction, working against liquid as it flows towards the pump inlet.

Typically atmospheric pressure (vented supply tank), but can be different for closed tanks. • Don’t forget that altitude affects atmospheric pressure.• Always positive (may be low, but even vacuum vessels are at a positive

Can be positive when liquid level is above the centerline of the pump (called static head) • Can be negative when liquid level is below the centerline of the pump (called suction lift) • Always be sure to use the lowest liquid level

Must be subtracted in the end to make sure that the inlet pressure stays above the vapor pressure.Remember, as temperature goes up, so does the vapor pressure.

Pipe Name dH (meters)73 Pipe 0.0009964452374 Pipe 0.00016607422 Pump Suction side Pipes Head Looses =75 Pipe 0.0001037963876 Pipe 0.0029062987377 Pipe 0.003321484178 Pipe 079 Pipe 080 Pipe 081 Pipe 082 Pipe 083 Pipe 084 Pipe 085 Pipe 0.0001037963886 Pipe 087 Pipe 088 Pipe 089 Pipe 090 Pipe 091 Pipe 092 Pipe 0.0001328593793 Pipe 0.0001328593794 Pipe 0.0001328593795 Pipe 0.0001328593796 Pipe 0.0001328593797 Pipe 0.0001328593798 Pipe 099 Pipe 0

100 Pipe 0101 Pipe 0102 Pipe 0103 Pipe 0114 Pipe 0.00020759276

X115 Pipe 0X116 Pipe 0X117 Pipe 0X118 Pipe 0X119 Pipe 0X120 Pipe 0121 Pipe 0122 Pipe 0.00012455565123 Pipe 0124 Pipe 0125 Pipe 0126 Pipe 0127 Pipe 0128 Pipe 0129 Pipe 0.00016607422

130 Pipe 0.01079079535131 Pipe 0.20142819815132 Pipe 0.10790605768133 Pipe 0.00008303711134 Pipe 0.00124555658135 Pipe 0.00008303711136 Pipe 0.00033214846137 Pipe 0.00719380646

0.0174987

Valve Name dH (meters)76 Valve 0.004516480693 Valve 0.0008581313 Total Head losses in Valves =

0.0053746119

Bend Name dH (meters)75 Bend 0.000296746977 Bend 0.000296746978 Bend 0.0002967469 Total Losses in Bends = 0.002374

107 Bend 0.0002967469118 Bend 0.0002967469119 Bend 0.0108927114120 Bend 0.0108927114122 Bend 0.0002967469123 Bend 0.0002967469124 Bend 0.0002967469