pipe size - bsi engineering

November 10, 2020

White Paper - Volume 7

Headquarters Address:[email protected]:

www.bsiengr.comWebsite:

300 E-Business Way, Suite 300Cincinnati OH 45241Phone: 513-201-3100 Fax: 513-201-3190

Pipe SizeRules of Thumb

2 Abstract

3 Rules of Thumb

4 Summary

CONTENT

1Pipe Size Rules of Thumb

ABSTRACT

There are several methods to size pipe that vary in complexity. Choosing pipe diameter is a balance between pumping cost and piping cost. Larger diameters have less frictional losses and decrease the cost to pump a given flow. While at the same time, larger diameter pipe costs more to purchase and install. There are also sizing differences between high and low viscosity liquids, and between liquids and gases. To get an idea of an optimal pipe size, you can use rules of thumb for a quick evaluation for a given situation, and then confirm pipe sizing by evaluating pressure drop.


RULES OF THUMBRULES OF THUMB

Typically Rules of Thumb are based on the Fluid velocity inside the pipe.

In the case of gravity flow, the size would need to be adjusted larger if the pipe is partially full.

Fluid Type of Flow Reasonableft/sec

Fluid Velocitym/sec

Thin Liquid(Water like Viscosities)

Gravity Flow 0.5 - 1 0.15 - 0.3

Pump Inlet 1 - 3 0.3 - 0.9Pump Discharge 4 - 10 1.2 - 3Process Line 4 - 8 1.2 - 2.4

Viscous Liquid Pump Inlet 0.2 - 0.5 0.06 - 0.15

Pump Discharge 0.5 - 2 0.15 - 0.6Steam (25 psig) 50 - 100 15 - 30Steam (100+ psig) 100 - 200 30 - 60Air or Gas (25-50 psig) 50 - 100 15 - 30

VISCOUS LIQUID FLOW (FT/SEC) VISCOUS LIQUID FLOW/SLURRIES/SUMMARY

SLURRIES

Lower velocities will cause solids to settle out while higher velocities will lead to pipe erosion.

Another Rule of Thumb for liquid flow in pipe based on flow rate in gallons per minute:

Pipe diameter (in) = √(Flow (gpm)/20)

To minimize static charge for flammable liquid, pipe velocity is 15 ft/s maximum. This maximum is reduced to 3 ft/s when entering a bulk storage tank until the inlet pipe is submerged.

SUMMARYThese estimates are good for getting started. Every piping situation varies. After choosing an initial pipe size, evaluate overall pressure drop for the piping system. Pressure drop will also have an impact on the pipe diameter chosen. For optimal sizing, contact BSI Engineering for help.


Pipe SIze (inches) 50 cP 100 cP 1000 cP1 1.5 - 3 1 - 2 0.3 - 0.62 2.5 - 3.5 1.5 - 2.5 0.5 - 0.84 3.5 - 5 2.5 - 3.5 0.8 - 1.28 4 - 5 1.3 - 1.8

Type of Solids Size of SolidsMesh No

Minimumft/s

Flow Velocitym/s

Fine over 200 3 - 5 1 - 1.5Sand 200 - 20 5 - 7 1.5 - 2Coarse 20 - 4 7 - 11 2 - 3.25Sludge 2 - 9 0.6 - 3

BSI Engineering is a full-service provider of engineering and design services for a very broad range of industry sectors.

The majority of our 200+ employees have over twenty years of technical experience and are ready to add their expertise to your project from any of our midwestern office locations. We deliver exceptional value for our clients wanting a fully integrated, engineering-led EPCM model.

THANK YOUFOR CHOOSING US!

300 E-Business Way, Suite 300Cincinnati OH 45241

Phone: 513-201-3100Fax: 513-201-3190

E-mail: [email protected]: www.bsiengr.com


pipe size - bsi engineering

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