COZBY ENTERPRISES, INC.

Three Important Formulas

Reference: Marks Standard Handbook for Mechanical Engineers, Eighth Edition, 1978

Valve and Port Sizes Flow area of valves and cross section of ports are usually determined by port area = AS/C in², where A is net piston area, in², S is mean piston speed, ft/min, and C is a constant, ft/min. Values of C are approximately 9,000 to 15,000 ft/min for inlet and 6,000 to 7,000 ft/min for outlet. Small valves and ports represent lost work.

Reference: Marks Mechanical Engineers Handbook, Fourth Edition, 1941, page 325

Isentropic Expansion of Superheated Steam

The isentropic expansion of superheated steam is fairly represented by

pvⁿ = const, with n = 1.315.

The volume at the end of expansion is V₂ = V₁(p₁/p₂)^1/n

Reference: RYERSON, Joseph T. Ryerson & Son, Inc., Steel, Special Metals, Spokane, Washington, Edition 121, pages 135 and 138

Bursting Pressures, Steel Fluid Line Tubing

Per Barlows Formula Burst P = 2ST D

S = Allowable Fibre Stress, T = Wall Thickness, D = O.D.

S is the tensile strength in PSI. One must consult RYERSON STEEL & ALUMINUM DATA BOOK for specifications, properties, etc.