U. S. Steel Tubular Products

Product Size and Pressure Calculators

	Standard and Line Pressure Calculations
		Standard & Line Product Data Tables
		Oil Country Casing Product Data Tables
		Oil Country Tubing Product Data Tables

Material Standards
U. S. Steel Tubular Products USS Material Standards are specifications not covered by a society, association or other specifying body. The following includes the material standards used most frequently for tubular applications.

USS M1020	Plain End ERW Pipe for Water Well Applications
USS M1021	Plain End ERW Pipe for use in Structural Applications
USS M1024	Seamless Mechanical Tubing in sizes from NPS 2 through 26
USS M1029	Plain End Seamless Pipe for use in General Purpose Applications
USS M1400	Constructional Alloy Steel Seamless Mechanical Tubing—Grades USS  “T-1” type A and USS “T-1” type B.
USS M1407	ERW Pipe NPS 8 thru 12 Intended for use as Lift Devices ( Casing or Piston Pipe Components)
USS M1430	Seamless Slurry Pipe. Weldable. Intended for transportation of solids in slurry form. USS M2430 covers ERW pipe for similar use.
USS M1431	Seamless Slurry Pipe to be Heat Treated. Primarily for mechanical joining.
USS M1470	Seamless Steel Pipe for Fabrication into Ordinary Welding Fittings
USS M1471	Seamless Steel Pipe for Fabrication into High Strength Welding Fittings
USS M1475	Seamless Steel Pipe for the Manufacture of Cold Formed Fittings
USS M2430	ERW Pipe intended for transportation of solids in slurry form.

Pressure Determinations
Barlow's Formula is commonly used to determine the following:

	Internal Pressure at Minimum Yield
	Ultimate Bursting Pressure
	Maximum Allowable Operating Pressure, and
	Mill Hydrostatic Test Pressure
This formula is expressed as P = 2St / D , where
	P = pressure, psig t  = nominal wall thickness, inch D = outside diameter, inch S = allowable stress, psi, which depends on the pressure being determined.

To illustrate, assume a seamless piping system 8 5/8" OD x 0.375" wall specified to ASTM A106 Grade C which has a specified minimum yield strength (SMYS) of 40,000 psi and a specified minimum tensile strength (SMTS) of 70,000 psi.

Some safety codes and regulatory agencies also assign a longitudinal joint factor to account for weld efficiency. The more common are 0.85 for ERW pipe and 0.60 for CW pipe. Seamless pipe enjoys a joint factor of 1.00. This means that some designers consider ERW pipe 85 percent as efficient as seamless pipe and CW pipe only 60 percent as efficient for the same application. Therefore, for a given application, ERW pipe would require a heavier wall than seamless pipe, and CW pipe, in turn, would require a heavier wall than ERW pipe. 

Distributors who stock pipe in a combination of seamless, ERW and CW must exercise extreme care to see that pipe with joint efficiency factors of 0.85 or 0.60 is not used on jobs which require pipe with a joint factor of 1.00.

Wall Thickness
Barlow's Formula is also useful in determining the wall thickness required for a piping system. To illustrate, assume a piping system has been designed with the following criteria:

Wall thickness does not affect the outside diameter; only the inside diameter is affected. For example, the outside diameter of a one-inch extra-strong piece of pipe compared with a one-inch standard weight piece of pipe is identical; however, the inside diameter of the extra-strong is smaller than the inside diameter of the standard weight because the wall thickness is greater in the extra-strong pipe.