4.1 Design Requirements for Liquefied Petroleum Gas Storage Tank The selection of the engineering design unit for the LPG storage tank system shall be responsible by the project organization department of each provincial (municipal, district) company. The selection should be made from the shortlisted design institutes, and the responsible leader must sign and approve. 4.2 Site Inspection 4.2.1 The site inspection should be organized by the project organization department of each provincial (municipal, district) company, involving departments such as construction, piping, and safety from the branch of the gas station, as well as the design institute. 4.2.2 For the investigation and survey of the gas station, it is necessary to understand the existing internal buried pipeline layout and cable laying depth. For stations unable to provide on-site pipeline documentation, pipeline detection technology should be used to determine the existing processes, electrical, and water supply and drainage pipelines. 4.2.3 The construction department of the branch in the location of the gas station should propose suggestions for the scope and methods of renovation, including the oil unloading vapor recovery system, refueling vapor recovery system (dispersed, centralized), and gas emission treatment facilities, based on the principle of economy and practicality and relevant requirements of the local government. After approval from the responsible leader and the project organization department of the provincial (municipal, district) company, the design unit will proceed with the scheme design. 4.3 Design Proposal 4.3.1 The design proposal submitted by the design institute should include technical documents such as the general layout, vapor recovery process diagram, and main equipment and material list. 4.3.2 The design proposal should be reported to the project organization department of the provincial (municipal, district) company, which will then organize the inspection departments, as well as the construction personnel of the branch of the gas station and the design institute for review, and report to the responsible leader for approval. 4.4 Construction Drawing Design 4.4.1 The selection of equipment should be provided by the project organization department of each provincial (municipal, district) company with a list of prequalified suppliers for vapor recovery equipment. The design institute will select the relevant equipment based on this list. Equipment selection should adhere to principles of safety and reliability, advanced technology, economic practicality, and compliance with emission standards, using products that are simple to install, convenient, and have minimal on-site modifications. Attention should be given to the following: 4.4.1.2 It is advisable to choose equipment from the same manufacturer within the same area for easier after-sales service. 4.4.1.2 Gas stations with an annual gasoline volume of over 3,000 tons and more than 10 fuel guns should opt for a centralized refueling vapor recovery system; others should choose a dispersed system. 4.4.1.3 Different types of vapor recovery technology and equipment should be selected based on the internal space of the fuel dispenser. For example, a secondary recovery dispersed vacuum pump should be powered by a smaller motor, utilizing the existing power supply of the fuel dispenser, rather than laying additional power cables. To minimize the tank modification volume, a centralized vacuum pump should be driven by electricity, not by an oil immersion pump. 4.4.1.4 The gas emission treatment facility should be selected based on the surrounding environment, site size, and business volume of the gas station. The maximum processing capacity of the gas emission treatment facility should be 10% to 20% of the maximum fuel volume. 4.4.2 Construction Drawing Design 4.4.2.1 The design institute will prepare the construction drawings based on the approved design proposal. 4.4.2.2 The LPG storage tank pipeline should use seamless steel pipes that comply with the current national standard " Seamless Steel Pipe for Fluid Transportation" GB/T8163. The design pressure for oil pipelines should not be less than 0.6 MPa, and the design pressure for vapor recovery pipelines should not be less than 0.13 MPa. Flexible materials such as thermoplastic plastic pipelines should not be used.
Attachment: Safety valves and pressure gauges are mandatory for strict inspection and must be reported to the local quality supervision bureau. This ensures better user experience. If the pressure gauge malfunctions, your end-user's gas consumption under pressure is unknown, and you cannot use it with peace of mind, fearing issues with the liquefied gas storage tank. Both the air compressor and the storage tank itself have safety valves. When pressure exceeds the safety valve's set range, it will automatically relieve pressure, and the pressure gauge plays a significant role. Therefore, daily components of special equipment must be used with caution. In case of any issues, first confirm if the steel plate thickness of the storage tank meets standards, and if not, determine the cause of the steel plate corrosion. Also, reconfirm that safety valves, pressure gauges, and other auxiliary equipment meet requirements. If all are found to be non-compliant, the local technical supervision bureau of the enterprise issues a non-compliance inspection notice, and the enterprise replaces the new pressure vessel upon receiving the notice.
