Water Velocity in Schedule 40 Pipes

[slickstyles5]

Hi,

I am wondering if there are ruel of thumbs to respect for water supply velocity in Schedule 40 pipes? I performed the calculations and the pressure drops are ok but I am just wondering what kind of velocity I should target. I am supplying cooling water to a dynamometer at 750 GPM in a 6" pipe and the veoclity is approx. 8 ft/s. Is this too high? Are there velocity figures that shall be respected?

Regards,

Gabriel Leblanc

 

[SNORGY]

In relatively clean water service you will be OK at 8 ft/s.

API 14E is the most common guideline that I know of for erosional velocity concerns. In Imperial units, I think the magic number to not exceed is about 8,000 to 10,000.

Regards,

SNORGY.

 

[vpl]

"General rules of thumb" that I've used are (for heat exchangers):

Over 3 ft/sec to avoid corrosion due to MIC; less than 10 ft/sec to avoid erosion.

Patricia Lougheed

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[rmw]

I just found the formula and did a calc yesterday for a Hx regarding sediment 150 microns and larger and the required velocity was 10.14 fps to keep it in suspension. Funny, I can remember that value but I can't remember where I found the formula or what I was doing.

rmw

Now it comes to me - it was from Cameron's Hydraulic.

PPS: Patricia, since we know you work in nuclear and most of that is stainless (or better), 10 fps seems a little low for stainless, huh????

 

[vpl]

rmw

Wish it was all stainless, but it's not. Lots of bronze and carbon steel still around. Seen more than a few heat exchangers where they had to retube.

Patricia Lougheed

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[rmw]

Patricia,

OK, now I understand where you are coming from. You have my sympathy. (So does your steam generator tubes and turbine blades.)

rmw