49 CFR § 192.105 - Design formula for steel pipe.

---
identifier: "/us/cfr/t49/s192.105"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 192.105 - Design formula for steel pipe."
title_number: 49
title_name: "Transportation"
section_number: "192.105"
section_name: "Design formula for steel pipe."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "D"
subchapter_name: "PIPELINE SAFETY"
part_number: "192"
part_name: "TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 185(w)(3), 49 U.S.C. 5103, 60101  and 49 CFR 1.97."
regulatory_source: "35 FR 13257, Aug. 19, 1970, unless otherwise noted."
cfr_part: "192"
---


# 192.105 Design formula for steel pipe.

(a) The design pressure for steel pipe is determined in accordance with the following formula:

*P* = (2 *St/D*) × *F × E × T*

*P* = Design pressure in pounds per square inch (kPa) gauge.

*S* = Yield strength in pounds per square inch (kPa) determined in accordance with § 192.107.

*D* = Nominal outside diameter of the pipe in inches (millimeters).

*t* = Nominal wall thickness of the pipe in inches (millimeters). If this is unknown, it is determined in accordance with § 192.109. Additional wall thickness required for concurrent external loads in accordance with § 192.103 may not be included in computing design pressure.

*F* = Design factor determined in accordance with § 192.111.

*E* = Longitudinal joint factor determined in accordance with § 192.113.

*T* = Temperature derating factor determined in accordance with § 192.115.

(b) If steel pipe that has been subjected to cold expansion to meet the SMYS is subsequently heated, other than by welding or stress relieving as a part of welding, the design pressure is limited to 75 percent of the pressure determined under paragraph (a) of this section if the temperature of the pipe exceeds 900 °F (482 °C) at any time or is held above 600 °F (316 °C) for more than 1 hour.

[35 FR 13257, Aug. 19, 1970, as amended by Amdt. 192-47, 49 FR 7569, Mar. 1, 1984; Amdt. 192-85, 63 FR 37502, July 13, 1998]