After a period of use, the impurities in the crude oil will deposit on the bottom and wall of the tank, reducing the effective capacity of the tank, affecting the efficiency of the tank, so the oil tank needs regular inspection, maintenance and removal of silt in the tank.
Oil tank cleaning is a dangerous tank operation, because oil vapor is not only flammable, explosive, but also toxic. Therefore, the following safety requirements must be strictly observed when washing cans.
Safe operation process of oil tank cleaning operation:
1. When cleaning the oil tank, the general workers should be outside the tank.
2. Operating procedures are: (1) emptying residual oil; (2) dismantling pipelines; (3) flushing with water; (4) steam sweeping; (5) flushing with water again; (6) draining or sucking dirt and blowing dry with low pressure ventilation.
3, when pumping class A and B oil, pistons should be used.
3. Steam sweeping: The steam of 65-70 C and 0.25-0.6 MPa is used to enter the bottom of the tank, the hole cover is opened moderately, and the ventilation is 6-8 hours. Steam nozzles should be straddled and grounded.
5. When the dirt is mixed, the vacuum pump or reciprocating pump can be driven by the explosion-proof motor. Pay attention to the grounding of the motor housing, and the pump should be 3 meters away from the oil tank.
6. The steam purge of an oil tank can also be replaced by an automatic tank cleaner. But before the tank can be put into the tank,
(1) the tank cleaner should be electrically connected with the oil tank.
(2) the cleaning time of the tank cleaner usually takes about 1~2 hours. The requirement for pumping pollutants is the same as above.
(3) it should be confirmed that the oil vapor concentration in the tank is not greater than 25% of the lower limit of explosion.
7, conditional gas stations can use oil tank cleaning trucks for oil tank cleaning and leak detection operations.
8, oil and gas testing should strictly abide by the relevant safety technical regulations.