1
Overview
JIS G3458 specifies seamless alloy steel pipes, known as STPA, used primarily for piping at high temperatures. It is the Japanese equivalent of ASTM A335.
2
Scope & Applicability
Applies To Industries
Power PlantRefinery
Covers — seamless chrome-moly pipe:
- Grades STPA 12, 22, 23, 24 (roughly equivalent to P11, P22, etc.).
- High-temperature and creep service in power boilers and process heaters.
Does NOT cover (exclusions) — the following are governed elsewhere:
- Carbon steel high-temperature pipe → JIS G3456 (STPT).
3
Key Requirements
STPA materials must resist high-temperature degradation:
- Manufactured exclusively as seamless pipes.
- Requires precise heat treatment to achieve creep-resistant microstructure.
4
Technical Details
STPA pipes utilize Chromium for high-temperature strength and oxidation resistance, and Molybdenum for creep resistance, allowing operation well above the limits of carbon steel.
5
Engineering Notes
Like all chrome-moly pipes, STPA requires strict preheating and Post-Weld Heat Treatment (PWHT) to prevent cold cracking in the heat-affected zone.
7
Source, Edition & Status
- Publisher
- JIS
- Industries
- Power Plant, Refinery
- Last Reviewed
- 2026-07-01
- Last Updated
- 2026-07-01
- Verified By
- Engineering content reviewer
- Content Status
- reviewed