1.7 bar means 17m TDH

[naifmbo]

is it true, 1.7 gauges reading difference means 17m TDH with same suction - discharg pipe sizes?

 

[friartuck]

a. I assume your gauge reads in metres??? or is it Bar.??
b. You are measuring across the pump.
c. I assume that the pump is horizontal.
d. The inlet and outlet connections are the same.??

does TDH mean Total Dynamic Head??

1 Bar = 10.2m head

so 1.7 bar (assume this is the case) = 1.7x10.20=17.34m head

dynamic head (if thats what you want) is half rho v squared

or 0.5 x 1000 x say 1m/sec sq (Assuming 1m/sec vel)

= negligible.

You will find the static head is high and the velocity head is low with most pumping applications. With air the velocity head is more significant.

Friar Tuck of Sherwood

 

[25362]

Pressure readings in Pa or N/m² convert to heads in m, by dividing them by [ρ].g. Where [ρ] is the fluid density, kg/m³, and g the acceleration of gravity at the point of measurement, m/s².

 

[naifmbo]

may be my question not clear.ok
in other hand , to replace that pump i need pump with my flow rate=xxxx at that gauges reading difference (in bar)=1.7 bar or 17 meter .

 

[25362]

To naifmbo:

1. 1.7 bar is 17 m only for liquids with a density of 1 kg/L, such as water.

2. 1.7 bar for a hydrocarbon of density 0.6 kg/L would mean 28.3 m differential head.

3. The new discharge head (or pressure) for the new pump would have to overcome the new system's resistance: friction drops, static pressures, elevations at the new given flow rates.

4. The suction head (or pressure) of the new pump will also be affected by flow rates, friction drops, etc., and may be that a check of the new available NPSH to be >>> required NPSH, would have to be carried out.