“What is the specific scope of “high-temperature, high-pressure, flammable, explosive, and toxic media”?
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“What is the specific scope of “high-temperature, high-pressure, flammable, explosive, and toxic media”? For example, what is the temperature at which high temperature is considered to be reached? High pressure refers to a pressure level that is above a certain threshold, and so on. I would be greatly grateful if someone with more experience could advise me. This post was last edited by Yanyang’s Steel on 2009-4-1 09:31]
Relevant information has been collected; the summary may not be comprehensive. The original poster can check the relevant standards: 1. Classification of pressure levels: Pressure can be divided into internal pressure and external pressure (vacuum). Internal pressure can also be divided into four pressure grades based on the design pressure: Low pressure: 0.1 MPa ≤ p < 1.6 MPa; Medium pressure: 1.6 MPa ≤ p < 10.0 MPa; High pressure: 10 MPa ≤ p < 100 MPa; Ultra-high pressure: p ≥ 100 MPa. 2. Temperature classification: Low temperature: Design temperature ≤ -20°C. Room temperature: Design temperature > -20～200°C. Medium temperature: Design temperature > 200–450°C. High temperature: Design temperature > 450°C. 3. Fire hazard: 3.1 Flammable gases – Category: Lower explosion limit of the mixture of flammable gas and air. Class A: <10% (by volume); Class B: ≥10% (by volume). 3.2 Liquefied hydrocarbons, flammable liquids – Category and names: Characteristics. Class A: Liquefied hydrocarbons with a vapor pressure > 0.1 MPa at 15°C, as well as other similar liquid substances. Class B: Flammable liquids other than those in Class A, with a flash point < 28°C. Class A: Flash point ≥28°C to ≤45°C; Class B: Flash point 45°C to <60°C. Class C: Flash point ≥60°C to ≤120°C; Class D: Flash point >120°C. 4. Fire and explosion hazards – Category and characteristics: Class A: 1. Flash point
1. Pressure level classification: Low pressure: 0.1 MPa ≤ p < 1.6 MPa; Medium pressure: 1.6 MPa ≤ p < 10.0 MPa; High pressure: 10 MPa ≤ p < 100 MPa; Ultra-high pressure: p ≥ 100 MPa. 2. Temperature classification: Low temperature: Design temperature ≤ -20°C. Room temperature: Design temperature > -20～200°C. Medium temperature: Design temperature > 200–450°C. High temperature: Design temperature > 450°C. 3. Fire hazard: Flammable gases. Lower explosion limit of mixtures of flammable gases with air: Class A < 10% (by volume); Class B ≥ 10% (by volume). Liquid hydrocarbons, flammable liquids: Class A A – Hydrocarbon liquids with a vapor pressure > 0.1 MPa at 15°C and other similar liquids; Class A B – Flammable liquids other than those in Class A A, with a flash point < 28°C. Class B A – Flash point ≥ 28°C to ≤ 45°C; Class B B – Flash point 45°C to < 60°C; Class C A – Flash point ≥ 60°C to ≤ 120°C; Class C B – Flash point > 120°C. 4. Fire and explosion hazard: Class A: (1) Flash point