Lifting scheme of FRP storage tank

2020-07-31 16:36:30 0

1. purpose FRP tank has the characteristics of light weight, corrosion resistance, low maintenance cost, long service life, low cost, convenient and quick installation, etc. This guide is intended as a manual for hoisting, installation, use and maintenance of FRP storage tanks. Avoid damage as much as possible and ensure its service life as much as possible. 2. Hoisting Conventional protection measures shall be taken for storage tanks during shipment or lifting at the destination: 2.1 must abide by the relevant lifting operation procedures, should be in the appropriate position of the storage tank tie rope, so as to avoid the storage tank swing out of control. 2.2 to lift smoothly, it is necessary to ensure that the tank does not fall off during lifting, and prevent it from falling or colliding with other objects. The resulting damage may lead to cracks in the internal corrosion-resistant layer, leakage and structural layer damage, and decrease in strength. 2.3 should be hung on the lifting lug, it is forbidden to pipe fittings, manhole for lifting. 2.4 the distance from lifting hook to lifting lug should be greater than the distance between lifting lugs or be lifted with cross arm. 2.5 It is best to use ropes or braided belts with sufficient strength to bind the barrel for lifting the tank without lifting lugs. When using chains or wire ropes for lifting, adequate protection shall be provided to prevent skid and scratch. 2.6 When a vertical flat-bottom tank is placed vertically, enough soft quality assurance pads should be placed on the rotating point at the bottom of the tank, which can be lifted carefully through the top manhole cross arm, and guide cables should be tied at appropriate positions to control the direction and avoid swinging. 2.7 All storage tanks must be lifted by empty tanks, and it is forbidden to lift storage tanks containing liquid or other heavy objects. 2.8 attention: the lifting process should be slow and steady! Prevent impact, shaking, slipping and accidents. 3. The temporary storage site of the storage tank should be a safe zone away from the fire source and free from accidental impact, and the ground should be flat and free of sharp protrusions. It is necessary to avoid overturning and rolling due to strong wind or inclination, and fix it properly when necessary. 4. Installation 4.1 Foundation 4.1.1 The foundation on which the storage tank is placed shall have sufficient bearing capacity to avoid the deformation or damage of the storage tank due to non-uniform settlement during use. 4.1.2 The interface pipe, drain port and vent port of the tank shall not contact with the foundation, and gaps shall be reserved in the corresponding parts of the foundation. 4.1.3 The foundation of vertical flat-bottom tank must be larger than the bottom area. 4.2 Installation 4.2.1 Storage tanks are not allowed to slide on rough ground. Work near the storage tank or in the storage tank should be very careful to avoid tools or other objects colliding with the storage tank. When using ladders, the contact points with the storage tank should be padded, and soft shoes should be worn when operating in the storage tank. 4.2.2 When the storage tank is to be moved during the installation process, lifting facilities should be used, and it is forbidden to use crowbar to pry the tank directly. 4.2.3 Vertical flat-bottom tank is best to use sand mattress layer, with sand bed thickness (30~80mm or more than 10mm rubber pad). When placing, first lay the sand layer into a cone shape, and repeatedly drop the tank (gently lift and slowly drop) to flatten the sand layer, so as to ensure that the whole bottom surface of the bottom of the tank contacts the sand bed. The outer edge of the sand bed should be equipped with a device to prevent sand from losing. It is suggested that the outer edge should be surrounded by bricks, and asphalt should be poured on the sand bed to seal the tank wall and the brick enclosure to prevent the rainwater flowing down from the tank wall from eroding the sand bed. Cement mortar can also be used as cushion to ensure a reliable continuous support layer at the tank bottom. Windproof feet shall be installed for outdoor use, and the number of windproof feet shall not be less than 4. When installing anchor bolts of windproof feet, the settlement and compression of sand bed should be considered, and anchor bolts can be tightened at full load (or test water), or rubber pads with thickness > >10mm can be placed between floor and cushion block.


.2.4 When the bottom and foundation surface of the small diameter vertical flat-bottom tank are very flat and there are no protruding parts, rubber pads can be placed directly on the foundation to install the storage tank. Acid and alkali resistant rubber pad thickness is 6-8mm, and shore hardness is a = 40-50. 4.2.5 The width of saddle bottom plate of horizontal tank shall not be less than 150mm, the supporting angle shall be greater than 120, and the width of supporting arc plate shall be 250-300 mm. The supporting arc plate of saddle shall be closely attached to the cylinder body and firmly padded with soft rubber pad. The foundation of the three saddle tank must be on the same horizontal plane. During installation, a shim should be used between the bottom plate and the foundation (ground), and the spot welding between the bottom plate and the shim should be firm. 4.2.6 All feet of the vertical round bottom (cone bottom) tank must be padded with the foundation, and the requirements for shim are the same as above. 4.2.7 The anchor bolts connecting the anchor bolt storage tank with the foundation shall be vertical, and the nuts of the anchor bolts shall be in good contact and fastened evenly. 4.2.8 The nominal diameter and pressure grade of the flange of the flange connection are consistent with the corresponding bolts and nuts gaskets, and the gasket material, specification and thickness shall meet the design requirements. Tighten bolts must be standardized, and they should be tightened symmetrically, alternately and sequentially. The tightening sequence of flanges and bolts should be tightened according to the following sequence: the strength of the connection between FRP flange nozzle and tank body in is limited, and the torque it can bear is also limited. If the limit is exceeded, cracks or leakage will occur in the neck of flange. Now, various pressure grades, flange crushing pressure, sealing pressure and bolt torque limit are listed: Pressure grade (MPa) 0.4 0.6 1.0 1.4 1.6 2.00 Crushing pressure (MPa) 1.38 2.76 4.14 5.52 6.9 8.3 Sealing pressure (MPa) 0.52 1.0 1.55 2.07 2.6 3.1 Torque limit of bolt (NM) 27.1 40.7 67.8 101.7 136 170 The connecting pipe between the and the tank should be connected from the tank flange to the external pipeline, that is, the tank flange should be used as the starting point for installing the pipeline, and it is not allowed to butt with the tank flange after the external pipeline connection is completed. The external connection pipe or valve of storage tank shall be independently supported, firm and reliable. Effective anti-vibration facilities should be adopted for the connection of vibration source, instead of the root of the flange of the storage tank being in a state of vibration for a long time. The external connection pipe of storage tank should take into account the deformation of storage tank foundation and tank body when tank liquid changes and the deformation of external pipeline due to temperature. During installation, straight pipe should be avoided to connect with storage tank, and elbow pipe (changing pipeline direction and reducing vibration source) is usually used to connect with storage tank. 4.2.9 Effective lightning protection facilities shall be adopted when installing and using storage tanks in outdoor open areas. 5. Use and maintenance 5.1 Use restrictions 5.1.1 The storage tank shall only be used under design conditions, and the use medium (including medium concentration), temperature and pressure shall not be arbitrarily changed. 5.1.2 The storage tank refers to the hydrostatic tank connected with the atmosphere, especially the vertical flat-bottom tank. It should be ensured that the tank is smooth with the atmosphere and will not be pressurized (positive and negative pressure) due to emptying, feeding or temperature change. The maximum working pressure of pressure storage tanks (vessels and towers) shall not exceed the design specified value. Unless specially designed, the cold and hot pipes of vibration sources (stirring and recoil devices) shall be isolated and supported from the tank body. 5.1.3 Do not load on the top of the storage tank at will. Negative pressure is strictly prohibited for atmospheric storage tanks! 5.1.4 No load shall be applied to the connecting pipe, and the connecting pipe with vibration source shall be provided with effective vibration avoidance facilities. 5.1.5 Do not approach the fire and keep away from the heat source. 5.2 Storage Tank Maintenance 5.2.1 When entering the tank for maintenance, all feed valves should be closed first, and the tank should be emptied and cleaned. After testing, it is confirmed that there is no toxic gas in the tank. Only when entering the tank can you enter the storage tank. Wear soft shoes, tie your seat belt and tie the other end of the seat belt to the top of the tank. Pay attention to the ventilation in the tank. Operation inside the tank must be carried out by personnel under the monitoring outside the tank. 5.2.2 To prevent the instruments from hitting the tank wall, use ladders and metal parts to add soft pads to the contact parts of the tank wall to protect the inner wall from being scratched and bruised. 5.2.3 Before climbing, the external ladders, cages and guardrails of storage tanks should be carefully checked for safety and reliability, and climbing is strictly prohibited in case of abnormality. 5.2.4 During maintenance, it is not allowed to load the top of the tank at will, and it is not allowed to exert external force on the connecting pipe. 5.25 After many years of use, outdoor storage tanks will cause resin layer peeling or fiber exposure due to aging of outer surface layer. It is suggested that paint or resin should be painted on the outer surface of the tank every two or three years to prevent aging and prolong the service life. 5.3HCL tail gas absorption device 5.3.1 Customers who purchase HCL tail gas absorption device produced by our factory shall prepare concrete foundation platform before installation, and the surface of foundation platform shall be kept flat and level. 5.3.2 Place the HCL absorption device on the platform and connect it with the storage tank according to the size of the connecting pipe flange. The diameter of the connecting pipe should be larger than smaller. No valve is allowed to be installed between the connecting pipe and the vent pipe, so as to ensure that the storage tank will not bear pressure when the air temperature changes and the materials are discharged and fed. 5.3.3 Always keep the water level at the overflow port.