fluid mechanics - pressure drop in a pipe

[Aurora09]

Hey guys, I hope you can help me out on understanding the concept of pressure drops in pipes. 

For the pressure drop equation P2 - P1 = pgHf (where Hf is frictional head loss), does this only apply to pipes when elevations are the same, z1 = z2? 

Also, if the pipe is sloped at an angle, then do I find the vertical height "h" and calculate the pressure drop as: pgh - phHf ? 

And finally my third question: If a pipe is vertical, does a pressure drop mean that the height in the water has risen? 

 

[cvanwy02]

My advice is to always start with the extended Bernoulli's equation and cross out terms which do not apply to the problem you are solving.  This worked very well for me.

 

[Slay the P.E.]

My advice is to always start with the extended Bernoulli's equation and cross out terms which do not apply to the problem you are solving.  This worked very well for me.

Absolutely the best advice for that question. 

@Aurora09, if you do this you will see that P2 - P1 = pgHf (where Hf is frictional head loss), is obtained for z1 = z2 and d1 = d2 where d is the pipe ID.   

Extended Bernoulli can also address your other questions regarding sloped and vertical pipes.

 

[pse19622]

I agree with the others - use Bernoulli and whittle it down as appropriate. My fluids professor in college required us to ALWAYS write out the equation first if we wanted credit, so it is ingrained in my memory forever lol.

EDIT: Can't believe I used "right" instead of "write"