Seamless Steel Pipe Pressure Pipeline

The Seamless steel pipeline's pressure rating consists of two parts:
1. Nominal pressure rating of standard fittings in nominal pressure;
2. The wall thickness rating of the standard pipe, expressed as a wall thickness rating.
pipeline pressure rating: usually the pipeline by the standard pipe nominal pressure rating and wall thickness level common to determine the characteristics of the pipeline pressure characteristics of the pipeline is called the pressure level. And used to simplify the description, often in the pipeline pipe nominal pressure rating is called the pipeline pressure level. The determination of the pressure level is the basis of the design of the pressure pipeline, but also the core of the design. It is a prerequisite for the design of pressure piping arrangements and pressure piping stress checking, as well as an important factor influencing pressure pipeline infrastructure investment and pipeline reliability.

Design conditions
On engineering, process parameters should not be directly as a pressure pipeline design conditions, to consider the process of operation fluctuations, the impact of connected equipment, environmental impact and other factors, and in the process of operating parameters on the basis of a certain security margin as a design condition. Here the design conditions mainly refers to the design pressure and design temperature.
The design pressure of the pipe shall not be lower than the pressure under the most severe conditions consisting of internal pressure (or external pressure) and temperature during normal operation.
The most stringent conditions are conditions that result in the maximum wall thickness of the pipe and pipe assembly or the highest nominal pressure rating.
Design pressure determination: Considering the influence of factors such as the hydrostatic column pressure of the medium, the design pressure should generally be slightly higher than the maximum working pressure under the most severe conditions consisting of (or) external pressure and temperature.

Design tempreture
The design temperature of the pipe shall not be lower than the temperature at the most severe conditions consisting of internal pressure (or external pressure) and temperature.
The most stringent conditions: the conditions leading to the maximum wall thickness of the pipe and pipe assembly, the highest nominal pressure rating or the highest material grade.
Design temperature to determine: consider the environment, heat insulation, operational stability and other factors, the design temperature should be slightly higher than the internal pressure (or external pressure) and temperature composition of the most demanding conditions under the maximum operating temperature.