What are the special requirements for the design and layout of vent pipes for toxic gas and liquid pipelines?

5.5.7 Equipment of Classes A, B, and C shall be equipped with emergency discharge facilities for accidents, and shall comply with the following provisions: 1. For equipment handling liquefied hydrocarbons or flammable liquids, it shall be possible to discharge such hydrocarbons or liquids from the equipment to a safe location; any remaining liquefied hydrocarbons shall be discharged into a flare； 2. For combustible gas equipment, it should be possible to discharge the combustible gas inside the equipment into a flare or a safe venting system. 5.5.8 The non-condensable gases from the top of the initial distillation column, the atmospheric pressure column, and the vacuum column of the atmospheric and vacuum distillation unit should not be discharged directly into the atmosphere. 5.5.9 A burst disc shall be installed in front of the safety valve of equipment handling high concentrations of ethylene oxide. The inlet pipeline of the rupture disc should be equipped with a nitrogen seal, and the outlet pipeline of the safety valve should be filled with nitrogen. 5.5.10 The exhaust gas from the ammonia safety valve should be treated before being released. 5.5.11 For combustible gases that cannot be discharged into a flare or the plant’s emission treatment system due to process conditions or properties of the medium, and are instead released directly into the atmosphere through exhaust stacks or vent pipes, the height of such stacks and vents must comply with the following requirements: 1. The top of the exhaust stack or the outlet of the vent pipe, for continuous emissions, must be at least 3.5 m above the roofs of platforms or buildings within a 20-m radius. No platforms or buildings should be located within a 45° upward slope range 20 m horizontally from the emission point (Figure 5.5.11) ； 2. The top of the exhaust stack or the vent opening for intermittent emissions shall be at least 3.5 m above the roof of any platform or building within a 10-m radius. No platforms or buildings should be located within a 45° upward slope range 10 m horizontally from the emission outlet (Figure 5.5.11) ； 3. The discharge outlet of the safety valve must not face adjacent equipment or areas where people walk; it should be at least 3 meters above the rooftops or platforms within a radius of 8 meters. Figure 5.5.11 Schematic diagram of the height of flammable gas exhaust stacks and vent pipes. Note: The shaded area represents the installation range of the platform or building. 5.5.12 For reaction equipment involving materials at risk of sudden overpressure or instantaneous decompression explosions, if the installation of safety valves is not sufficient, burst discs or a combination of burst discs and detonation tubes shall be used; the outlet of the detonation tube must be directed toward a safe area free from sources of fire ； Measures to prevent secondary explosions and fires should be taken when necessary. 5.5.13 Reaction equipment where overheating and overpressure may occur due to the exothermic polymerization or decomposition of materials, thereby potentially leading to fires or explosions, shall be equipped with alarm signals and pressure relief devices, as well as automatic or manually controlled emergency shutdown systems for feeding materials. 5.5.14 It is strictly prohibited to discharge together several gases that, when mixed, may undergo chemical reactions to form explosive mixtures. 5.5.15 Liquids, combustible gases with low calorific value, combustible gases containing oxygen or halogen elements and their compounds, combustible gases with extremely high or high toxicity, inert gases, acidic gases, and other corrosive gases shall not be discharged into the plant-wide flare system; separate emission systems or treatment systems must be installed for them. 5.5.16 Before the flammable gas vent pipeline is connected to the flare, equipment such as liquid separation and flame arrestors should be installed. 5.5.17 The condensate in the flammable gas vent pipeline shall be recovered in a sealed manner and must not be discharged indiscriminately. 5.5.18 Low-temperature flammable gas emission systems carrying flammable liquids shall be equipped with vaporizers, and the material selection for low-temperature flare pipes shall take into account the lowest temperature that may occur during accidental emissions. 5.5.19 Appropriate measures should be taken for the main pressure relief and discharge devices of the unit to reduce the instantaneous discharge load of combustible gases under accident conditions. 5.5.20 The torch shall be equipped with a constant-light source and a reliable ignition system. 5.5.21 The installation of elevated flares within the facility shall comply with the following provisions: 1. It is strictly prohibited for combustible gases discharged into the flare to carry along combustible liquids ； 2. The radiant heat from the flame should not pose a risk to personnel or equipment safety ； 3. Flammable gas venting shall not be installed within 30 m of the torch cylinder. 5.5.22 The installation of closed surface flares shall, in addition to being considered as open-flame equipment, comply with the following requirements: 1. The combustible gases fed into the flare shall not contain combustible liquids ； 2. The radiant heat from the flame should not pose a risk to personnel or equipment safety ； 3. The torch should have effective smoke suppression measures. 5.5.23 Auxiliary equipment for the flare facility shall be arranged near the flare.

It must pass through a dedicated tail-suction device to meet safety and hygiene standards before being discharged

The emission of toxic gases must be purified to meet specified standards before it can be released; treatment methods include chemical methods and incineration, among others

Reply to 2# sdkddjp: Hello, may I ask which standard this belongs to?

Reply to 2# sdkddjp: I also want to know which standard this is based on~~

Several nitrogen purging lines should be installed at the discharge pipe; it is recommended that the nitrogen flow rate be 15 Kg/H

This is GB50160-2008, Code for Fire Protection Design of Petrochemical Enterprises