Plastic Tubing in Saltwater System

[EGAtomic]

I am putting together a design spec for a saltwater system that includes plastic tubing and was wondering if there is any information on what the maximum flow velocities are for such tubing? The tubing within the system is teflon PFA, PEEK, and polyethylene varying in size from 1/16" to 1/4"; I have experience with metal piping in saltwater systems and know that piping like 90-10,70-30, and Ti have flow velocity limits to prevent excessive corrosion and erosion but is there a similar standard for plastic tubing?

 

[rconner]

[Don't know if same guidance is applicable at all for such small pipes or tubes, but you may be interested in

http://www.haywardflowcontrol.com/w...HaywardContent_10202_10053_-1_FC-FlowVelocity

.]

 

[EdStainless]

You need to understand why there are limits in the first place.
In clean water Ti and SS have no limits.
Even in clean water the Cu based alloys have limits because of the relatively soft passive films that form.
This film will erode even without any particulate in the water.

Is this water chlorinated?
If we presume no chemical attack I would expect that you will hit pressure drop limits before you reach velocity limits.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[EGAtomic]

Thank you @rconner that is somewhat what I was looking for, @EdStainless the water is not chlorinated, I was looking for this information because I am designing as well as writing up a design spec for the system and I needed some sort of guidelines for the design.

 

[rconner]

It should only be considered in the interesting flotsam and jetsam category, as opposed to any practical relevance to this OP, and blood may be considered also be a "non-Newtonian" fluid, but it is interesting that when one considers modern medical research e.g. as sumarized at

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC481953/

, a test for flow velocity (of course through those "non-metallic" tubes) of ten healthy young people after vigorous exercise revealed with regard to some blood flow velocity:

"Mean peak flow velocity rose from 0.91 m/s at supine rest to 1.36 m/s during maximum supine exercise."

As these values sort of define an English unit range of 3.0-4.5 ft/s flow velocity range, isn't it at least just a little fascinating that God and/or more than hundreds of thousands of years of evoloution have developed a seemingly efficient pumped transport system with flow velocities seemingly not a whole lot different than recommendations of modern hydraulic Engineers?