The quartz sand filter is the pressure vessel
In accordance with the special equipment safety law of the People's Republic of China, pressure vessel, refers to holding gas or liquid, carrying a certain pressure airtight device, its range for maximum working pressure is greater than or equal to 0.1 MPa (gauge pressure) gas, liquefied gas and the highest standard of working temperature is higher than or equal to the boiling point of liquid, volume is greater than or equal to 30 l and internal diameter (non circular cross section refer to the section within the largest geometry size) greater than or equal to 150 mm stationary containers and containers; All nominal working pressure is greater than or equal to 0.2 MPa pressure (table), and the product of the pressure and volume greater than or equal to 1.0 MPa, L standard of gas, liquefied gas, and the boiling point is equal to or lower than 60 ℃ liquid cylinders; Oxygen tank. Air filters do not have these conditions so they are not pressure vessels.
It isn't. Because of the pressure vessel is defined as: the working pressure is greater than or equal to 0.1 Mpa (work pressure refers to the pressure vessels under normal working condition, the top can reach the highest pressure (pressure)); (no liquid static pressure). The pressure in the water container is 3-4kg and 0.03 MPA. So it's not a pressure vessel.
Quartz sand filter is composed of standard tanks, depending on traffic, choose different number of standard tanks, allowing a single system filtering flow from 20 m3 / h to 1300 m3 / h. The system automatically switches the inlet and outlet valve when the system is in and out of the water pressure difference, but the water source can be used as the backwash water source. In the process of reverse washing, the tank in the fully automatic filtration system is backwashed in order, and only one can be washed at a time, and the other can continue to filter. On the one hand, it does not affect the normal operation of the filter system, and on the other hand, clean water from other standard filter can be used as backwater to prevent the backflow of dirty water to the filtration system.
