Fluid_Flow_Rules_of_Thumb_for_Chemical

8

Rules of Thumb for Chemical Engineers

Suggested Fluid Velocities in Pipe and Tubing (Liquids, Gases, and Vapors at Low Pressures to 50psig and 50~176

The velocities are suggestive only and are to be used to approxi- mate line size as a starting point for pressure drop calculations.

The final line size should be such as to give an economical balance between pressure drop and reasonable velocity.

Suggested Trial Velocity

Suggested Trial Velocity

Fluid

Pipe Material

Fluid

Pipe Material

Acetylene (Observe pressure limitations) Air, 0 to 30 psig Ammonia Liquid Gas Benzene Bromine Liquid Gas Calcium Chloride Carbon Tetrachloride Chlorine (Dry) Liquid Gas Chloroform Liquid Gas EthyleneGas Ethylene Dibromide Ethylene Dichloride EthyleneGlycol Hydrogen Hydrochloric Acid Liquid Gas Methyl Chloride Liquid Gas Natural Gas Oils, lubricating Oxygen (ambient temp.) (Low temp.) Propylene Glycol

Sodium Hydroxide 0-30 Percent 30-50 Percent 50-73 Percent Sodium Chloride Sol'n. No Solids With Solids

4000 fpm 4000 fpm

Steel Steel

6 fps 5 fps 4

Steel and Nickel

6 fps 6000 fpm 6 fps

Steel Steel Steel Glass Glass Steel Steel

5 fps (6 Min.- 15 Max.) 7.5 fps 6 fps

Steel

Monel or nickel

4 fps 2000 fpm

Perchlorethylene Steam

Steel

4 fps 6 fps

0-30 psi Saturated* 30-150 psi Satu- rated or super- heated* 150 psi up

4000-6000 fpm

Steel

5 fps 2000-5000 fpm

Steel, Sch. 80 Steel, Sch. 80

6000-10000 fpm

6 fps 2000 fpm 6000 fpm 4 fps 6 fps 6 fps 4000 fpm

Copper & Steel Copper & Steel Steel Glass

superheated *Short lines

6500-15000 fpm 15,000 fpm (max.)

Sulfuric Acid 88--93 Percent 93-100 Percent

Steel Steel Steel

4 fps 4 fps

S. S.-316, Lead Cast Iron & Steel, Sch. 80

Sulfur Dioxide Styrene Trichlorethylene Vinyl Chloride Vinylidene Chloride Water Average service Boiler feed

4000 fpm 6 fps 6 fps 6 fps 6 fps

Steel Steel Steel Steel Steel Steel Steel Steel

5 fps 4000 fpm

Rubber Lined R. L., Saran, Haveg

6 fps 4000 fpm 6000 fpm 6 fps 1800 fpm Max. 4000 fpm

Steel Steel Steel Steel Steel (300 psig Max.) Type 304 SS

3-8 (avg. 6) fps 4-12 fps 1-5 fps

Pump suction lines Maximum economi- cal (usual) Sea and brackish water, lined pipe Concrete

7-10 fps

Steel R. L., concrete, asphalt-line, saran- lined, transite

5 fps

Steel

5-8 fps~ 3 5-12 fpsJ (Min.)

Note: R. L. = Rubber - l ined s t ee l