I NEED EXACTELY TECHNICAL REASON WITH CALCULATION / THEORY . DEFINITELY THIS SHAPE INCREASES FLOW COEFFICIENT OR DECREASES VELOCITY HEAD . JUSTIFICATION REQUIRED . DO NOT CONFUSE WITH RETURNLINE PIPE CUT AT 45 DEGREE ? THAT THEORY / REASON IS DIFFERENT .

This message has been edited. Last edited by: mbsahoo,

HOPE SOMEONE WILL ANSWER IT .

Check out the Basic Ebook that can be opened from the Ebook Link on the home page of this Forum. What I've heard over the years about Suction and Return Lines is in Ch. 6-2,3.

The book is laid out with Baasic's first and then goes from the Tank to the Actautors so the component being discussed is followed by components that they will supply and/or control.
http://www.hydraulicspneumatics.com/200/eBooks/

This book may answer a lot of your questions and a bunch you you have not thought of yet. I used it to teach Basic Fluid Power to Mechanical and Electrical Engineeers and Maintenance persons.

Th Circuits book was used as an advanced class for anyone wanting to go beyond how parts worked and the Symbol that represented them and actually have information to help them design circuits.

checked http://www.hydraulicspneumatics.com /200/ebooks ,but could not find satisfied answer to me . It is mentioned that 45 degree cut provides no block of flow , if it touches tank bottom . But suction pipe is above 6 inch from tank bottom . So there is no chance of flow blocking . Even side mounting pump has suction pipe cut at 45 degree , where the chance of falling is less .
I ACKNOWLEDGE Mr MAGLUB suggetion for computing .
I will use bernoullis eqn. and simulation of suction circuit . Note the difference . The only parameter puzzles me is coefficient of discharge , What will be its value for this case , which is necessary for computing simulation result and friction loss .