Need Help with a Fluids Mechanics Problem?

An orificemeter, as shown in the figure, is often used to measure volume flow rate of fluids in pipelines. It consists of an orifice in the pipeline, and a differential manometer connected to the pipe wall to measure the pressure drop between points A and B. Fluid 1 flowing in the pipeline has a specific weight of 9.8 kN/m3, while the manometer fluid (Fluid 2) has a specific weight of 15.6 kN/m3. For a vertical pipeline with point A 0.5 m above point B, what will be the pressure drop pA − pB if the manometer reading is 50 cm? Based on the sign of the pressure drop term, what can you say about the flow direction in the pipe? Is it upward or downward?
Briefly explain your answer.
(The figure is in this link: http://img170.imageshack.us/my.php?image... )
Thanks in advance!

Answer:
*What is the diameter of orifice plate and verticle pipe?
*Please click on the link:
http://www.efunda.com/formulae/fluids/ca...
http://www.cheresources.com/high_dp_orif...

*As per the link given by you, that is:

(The figure is in this link: http://img170.imageshack.us/my.php?image... )
*Pressure difference shown by your manometer is the resultant P.D.That is m of fluid column which is having 15.6 KN/M^3.
*As per hydraostatic law:

Pa-Pb/specific weight
=h,
h=50 cm
h=0.5 m
Pa-Pb
=h*specific weight
=0.5*15.6
=7.8 KN/M^2
*7.8 kilonewton/square meter = 795.378 646 123 kilogram-force/square meter
*7.8 kilonewton/square meter = 7 800 pascal

Please go through the link I have given,it is having direct calculator and calculation help also.

Pressure drop in the pipeline is the difference between points P and Q.
According to Bernoulli's Principle (Navier-Stokes equations simplification, zero viscosity and incompressible flow), we can say:
P=rho(kg/m3)*gravity(m/s2)*hei...

Pipeline pressure is just static pressure (since input pressure hole is perpendicular to fluid1 flow, no dynamic pressure is obtained to the pipeline measure), flow speed in the pipeline is zero.

Therefore:
P=rho*g*h
Link to the hydrostatic pressure formula: http://en.wikipedia.org/wiki/hydrostatic...

or in your specific weight units:
p=rho*h=15.6KN/m3*0.5m=7.8KPa

As I wrote you to email (I copied and pasted it here but it didnt save it somehow):
Fluid 2 is pushed more by fluid 1 A input than B input, to have your figure configuration. So, the more it pushes the more pressure it has.Therefore, it flows downwards.

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