LPG TANK

　　The company has established a complete quality assurance system in accordance with the requirements of TSG Z0004-2007"Special Equipment Manufacturing,Installation,Transformation,and Maintenance Quality Assurance System Requirements",compiled quality assurance system documents,appointed quality assurance engineers and the responsibility of each quality control system Division to ensure the stability and improvement of product quality.

　　Advantages of raw material supply

　　The company has established strategic cooperation relationships with large steel groups such as Shansteel,Ansteel,Handan Iron and Steel,Wugang,etc.The procurement costs have been relatively reduced.More than 80%of the steel plates are fixed-rolled steel plates,and the level II ultrasonic qualification is guaranteed,which ensures the quality of the steel plates.The fixed-rolled steel plates are wide plates with a maximum width of 3700mm,which reduces the weld seam of the cylinder and is more conducive to ensuring product safety performance;The head plate for DN3000 and below basically realizes all fixed rolling.The head is an integral head without splicing welds,which improves the safety performance of the product.

　　Manufacturing resource advantages

　　The LPG storage tank adopts batch production and assembly line production mode.Through mechanized and highly automated equipment and process tooling,the production efficiency and product quality of the product are improved.The company has added CNC blanking,CNC machining center,CNC coil forming equipment,automatic submerged arc welding machine and other equipment.All longitudinal ring welds are automatically welded to achieve precise manufacturing and high level of quality control.The company has built a 25m×8m×10m gas-fired overall heat treatment furnace,equipped with an automatic control system and multi-channel temperature control equipment,and has an overall heat treatment capacity of 5-200m3 storage tanks.

　　Process control advantages

　　The company has established a stable process control system in accordance with the current national laws,regulations,standards,etc.Through continuous transformation and upgrading of new technologies and new process methods,the existing level of manufacturing processes has reached a higher level in the industry.Mature manufacturing and inspection methods have been formed at each process stage from material admission,blanking and cutting,barrel forming,group welding butt joints,component assembly,non-destructive testing,heat treatment control,pressure test,anticorrosive coating,etc.Efficiency and quality can be maintained at a high level.

　　Replacement

　　Before the equipment is newly put into use or long-term decommissioning,maintenance,and re-use after relocation,the air in the tank must be replaced(it is strictly forbidden to replace LPG directly without replacement).

　　1、Inert gas replacement method.That is,the air in the storage tank is directly replaced(diluted)with an inert gas.The inert gas mentioned here refers to non-flammable and non-combustible non-toxic gas,Such as:nitrogen,carbon dioxide,etc.Taking nitrogen as an example,it is briefly described as follows:Nitrogen is injected into the storage tank from the liquid inlet,and the pressure of the storage tank is increased to 0.6 MPa.After holding the pressure for 10 minutes,the gas is discharged from the sewage outlet.（The tank is always in a positive pressure nitrogen seal to prevent air from entering）Close the drain when the tank pressure drops to 0.2MPa（When venting,the gas-phase port,return port,and liquid outlet end-of-line valves can be opened momentarily,and the air in the pipeline can be removed by the way.）Repeat the above operation three or more times to complete the replacement of the storage tank.If it is replaced by carbon dioxide,the air is taken in from the liquid inlet and the air is taken out from the vent.The operation method is the same as above.This method has good reliability,high safety factor,and great success.This method is generally recommended.

　　2、Water replacement method.Replace the air in the tank with water,and then replace the water in the tank with inert gas.That is,water is used as a replacement intermediate medium.The operation process is briefly described as follows:1.Inject water into the storage tank from the sewage outlet.When the water overflows from the vent,the air has been discharged.2.Stop water injection,and then inject nitrogen into the storage tank from the vent,and open the drain port of the storage tank.The water in the storage tank flows out of the drain port under the pressure of nitrogen and its own weight,until the water in the storage tank is drained.3.Close the blowdown valve and continue to fill the tank with nitrogen until the pressure in the tank is 0.2 MPa,and always maintain a positive pressure nitrogen seal in the tank to prevent air from entering again.This method is simple to operate,safe and reliable,and has a short cycle.Note:When replacing with water,the hydrocarbon pump must not enter water.

　　3、Unloading operation

　　1.After the tanker enters the specified position and centered,turn off the engine,tighten the manual brake,and use triangle wood to prevent the tanker from sliding.

　　2、Check whether the tank body,valves,level gauges,pressure gauges and thermometers are normal,and whether the firefighting equipment is in good condition.

　　3、The static grounding line of the tank truck and the unloading platform is firmly connected,and the tank truck liquid level is adjusted and recorded with the tank truck escort.

　　4、The gas and liquid hoses on the unloading platform are firmly connected to the quick connector of the tank truck.Before sealing,check the sealing rubber ring to ensure that it is in good condition.

　　5、The oil pump handle of the tank truck is pressed to increase the oil pressure to 0.3 to 0.4 MPa to open the emergency shut-off valve of the tank truck gas and liquid phases.

　　6、Open the bleed angle valve,let out the air in the hose,and close the angle valve after the gas and liquid materials are ejected.

　　7、Open the manual gas and liquid valve of the tanker.

　　8、Open the tank to all valves on the tanker's liquid line.

　　9、Air is supplied to the gas-phase port of the storage tank by a pneumatic shut-off valve so that it is in the open position,so that the gas-phase port of the storage tank communicates with the gas-phase port of the tanker.

　　10、After checking to confirm,open unloading pumps,liquefied petroleum gas into the tank,in unloading tankers state.

　　11、During the unloading process,it is strictly forbidden to overfill the storage tank,the unloading speed should not be too fast,and the pressure difference between the tank car and the storage tank should not exceed 0.2MPa。

　　12、After the unloading,stop the unloading pump,close the storage tank gas and liquid phase valves,and manually operate the solenoid valve to make the gas phase emergency shut off and return to the closed state.Close the tank truck emergency shut-off valve and gas-liquid valve.

　　13、Open the exhaust valve of the tank truck to exhaust the residual gas in the dump truck hose.

　　14、Remove the hose,disassemble the static ground wire of the tank truck and the loading and unloading platform,and close the tank truck operation box.

　　15、Check the liquid level after unloading and sign the unloading operation record with the escort.

　　16、Check the site and start driving after 5 to 10 minutes of ventilation.

　　17、In the event of thunderstorms,nearby fires,gas leaks,abnormal pressures,and other unsafe factors,loading and unloading operations should be stopped immediately.

　　Filling operation

　　1、Open all valves in the liquid phase pipeline from the liquid outlet to the dispenser and open all valves in the return line.

　　2、The pneumatic cut-off valve gas at the liquid port is given so that it is in the open position,so that the liquefied petroleum gas in the storage tank communicates with the filling pump.

　　3、After confirming the status of each valve,turn on the filling pump.

　　4、According to the working state of the dispenser,determine whether the return line is in working state.(When the amount of dispenser is small,the pressure will cause the safety return valve to open and return to the storage tank through the return line).

　　5、For specific car refueling operations,refer to the refueling machine operation guide.

　　6、Stop the filling pump after filling.If the gas is not refilled for a long time,the emergency shut-off valve of the liquid outlet should be closed.

　　The customer base of LPG storage tanks is LPG stations throughout the country.

　　The customers of liquid ammonia storage tanks and liquid chlorine storage tanks are chemical plants.