Material selection for gas pipelines
Thread Content
According to the GB50028 Code for Design of Urban Gas Systems, for gas pipelines at medium and low pressures (below 0.4 MPa), steel pipes made of Q235B material can be used in accordance with GBT3091. However, the TSG D0001 Regulations on Safety Supervision of Pressure Pipelines stipulate that grade B normalized steels such as Q235B shall not be used for pipelines carrying highly hazardous toxic substances. I would like to ask the experts: can Q235B really be used for gas pipelines?
What is the basis for determining that gas does not pose a moderate level of hazard?
Refer to GB5044 for the classification of the degree of hazard associated with occupational exposure to toxic substances. Carbon monoxide is listed in Category II (high hazard) under this standard, and examples of industries where it is encountered include gas production, blast furnace ironmaking, and coking. Therefore, gas is a highly hazardous medium.
Gas is only flammable and explosive; it is not toxic. Carbon monoxide is definitely present in the gas production process, but not in the final product.
In general design, the gas used is considered to be of moderate hazard. If you have any objections, it is recommended to consult the local quality inspection department responsible for regulating pressure pipelines.
The carbon monoxide content in the gas we supply is around 16-20%, and it is used in the roasting furnaces of alumina plants; that’s why this question arises
Which standard or specification is used as the basis for classifying gas as a medium-hazard substance?
Gas is not an extremely highly hazardous medium
What is the basis for making this judgment?
The carbon monoxide content in gas, as mentioned by the poster, is around 16-20%, which means it is a highly hazardous substance. The gas here has a different composition from town gas.
Yes, we supply gas to industrial enterprises; our main customers are alumina plants and ceramic factories, etc., and the carbon monoxide content is relatively high