Pressures of a Pipe Line Header Having Incoming Different Pipe Streams

Any stream at a pressure below P4 will not flow into L4, nor will it affect the pressure in any way. Unless you give flows of each stream including the flow out of L4 no answer is possible.

homework??

Suppose, Flow in L1 = 25 cu.m/hr water @ 3.2 ksc (a) , L2=45 cu.m/hr water @ 1.2 ksc (a). I require the total i.e. 70 cu.m /hr at the common header ?? can all the three pipes have same nominal bore ??

Note. 80 NB for all the three pipes was the actual design.. I want to know the calculation procedure and the different parameters for sizing the diameter.. Also, is it based on continuity eqn. ??

<...can all the three pipes have same nominal bore ?...>

The economic diameter of any full pipe carrying liquid should ordinarily that which allows an average velocity between 1 and 3m/s.

Flammable non-ionic liquids should be ideally less than 1m/s so as to minimise the risk of static electricity build-up within them.

For the three lines L1,L2 and L3connect ,all connected for one header , they will all has the same pressure , So it's not right to assume different pressure in each line.

Different are in pressure losses in each individual line which is mainly depending on pipe diameter , flow rate , flow speed and pipe material in additional to pipe fittings.

All these factors affects pressure loss in each line separately..

So you have two ways.

*- if you need a definite flow rate , you have to calculate to obtain pipe diameter.

*- if you have a definite pipe diameter , you have to calculate to obtain flow rate