Thumb rules for designing water and pneumatic pipeline 3

[SAZIM]

I am an Electrical Engineer. In my Factory I have to make new pipelines for water and compressed air. But I have no idea to design this. I need to know the thumb rules for followings:

- Relation between pipesiz (dia) with pipe length and pump LPM
- Pressure drops on bends, reducer etc.
- Relation between pipe dia with compressed air pressure

Anyone please help me.

 

[MortenA]

Hire a consultant?

-or forget about pressure drop and size for max velocity. This should be below 6 m/sec for clean fresh water. The limit is mostly noise/erosion related and a sufficiently low velocity not to give too high a dP for plant piping.

Best regards

Morten

 

[MiketheEngineer]

Or review your hydraulics class from college

 

[cvg]

google the following:

Hazen Williams Equation
Pump curve
Pipe head loss or friction loss
Bernoulli equation
Minor losses
Pipe equivalent length

by the way 6 m/s is too high, recommend about half that

 

[StoneCold]

The Crane 410 Book will tell you how to size pipe, calc pressure drops, etc.
Although to get it all fabricated I would reccomend hiring a consultant to do the sizing and make drawings that you can send out for bids for construction.

Regards
StoneCold.

 

[racookpe1978]

Most piping engineers I know like to keep the fluids inside the pipe.

Unlike electrical engineering, when you have to keep the smoke inside the wires all the time, sometimes your boss and their customer wants you to let the fluids inside the pipes out of the pipes. It is recommended that you figure out a way to control such openings.

A few other hints and thumb rules.

Unlike wires and cables, where electrical engineers insist on stuffing their pipes full of copper and fiber-optic cables - which only serves to increase the resistance to the current they are trying to transmit! - piping engineers know they need to keep their new pipes hollow and empty. (Hollow pipes tend to transmit the most fluids.)

Most of your pipes will have a hole in both ends of the pipe. Try to keep these holes lined up with each other.

Almost all of your pipes will have the outside diameter bigger than their inside diameter. (Those that do not need to be installed backwards the other way inside out.)

At no point regardless of units or pipe size will a pipe EVER be defined by a measurable quantity. That is, if, at any time, you can measure a 1 inch length in any direction on any pipe, you do not have a 1 inch pipe.


Don't worry, you'll get the hang of it pretty soon:

Batteries and DC generators will now be called "pumps", unless they are "tanks" or "pressure vessels" - which are not "pumps".
"Resistance" is still "resistance", except when it is not because your pipe goes uphill or downhill. Or your pipe tries to go at one speed, but the water inside tries to go at a different speed to a different pressure, which isn't voltage.
High tension pipes are not like high pressure wires, but high pressure pipes are likely to be under high tension the other direction.
Switches are now called "valves", but "valves" are not "tubes" which are now "pipes" except "tubes" are not "pipes" although they look like "pipes" and (sometimes) act like "pipes."
AC current is now not good at all, and is called "surges" or "water hammer" when it is not being cursed thoroughly and roundly. In fact, most things with pipe are cursed roundly and thoroughly.
"Solder" is not "solder" unless you are in Spain when you try to connect pipes.
Welding is a magic way to glue round hollow things together by welders using welders to weld welds with weld rods.

Have fun. Hire experts. 8<)

 

[MortenA]

CVG look at the application! Its not a water main we are dealing with here but process plant piping. Here e.g. NORSOK says 6 m/sec and ISO 13703 says 5 m/sec for clean fluids. These are O&G standards i know but they cant be all that wrong!

For the air i wouldnt hessitate to go much higher. A good refernce would be V=175*(1/density)^0.43 og 60 m/sec whichever is lowest if pressure drop was not a concern (short lines). This is for noise. But be carefull that dP may be you sizing criteria here.

Best regrads

Morten

 

[cvg]

morten, just giving my thumb rule, you may have a different one. and we really don't know if it is process piping or just a domestic waterline do we?