A, the basic knowledge of the pump commonly used pump model code LG ----- high-rise building to the pump DL ------ multi-stage vertical water pump BX ------- fire fixed dedicated pump ISG ----- - Single-stage vertical pipeline pump IS ------- Single-stage horizontal water pump DA1 ------- Multi-stage horizontal water pump QJ ------- Submersible electric pump Model Meaning: Such as 40LG12-15; 40- import and export diameter (mm); LG-high-rise building feed pump (high speed); 12- flow (m3 / h); 200QJ20-108 / 8.200 --- said frame number 200; QJ --- submersible pump; 20-flow 20m3 / h; 108 --- head 108M; 8 --- series of 8 levels. The basic composition of the pump: motor, coupling, pump head (body) and machine base (horizontal). [See figure] The main parameters of the pump are: flow, Q said, the unit is M3 / H, L / S. Head, said H, the unit is M. For clean water pumps, the necessary NPSH (M) parameters are important, especially for suction type water supply equipment. Submersible pumps, rated current parameter (A) is very important, especially when used in frequency conversion water supply equipment. Motor's main parameters: motor power (KW), speed (r / min), rated voltage (V), rated current (A). Coupling pump head (body _) horizontal base B, the basic knowledge of the pressure vessel 1, pressure: pressure is the vertical force acting on the unit area of ​​the object. The exact name is the pressure intensity, referred to as pressure, used to call the pressure [kgf / cm2]. The unit of pressure is generally atmospheric pressure, expressed in kilograms per centimeter in engineering units, or expressed in water column or mercury column. The unit of international unity is Newton [N / mm2], Pa or Megapascal [MN / m2, Mpa]. 1 Engineering Barometric Pressure [kgf / cm2] = 0.098 Newton [N / mm2] = 0.098 Pa [MN / m2] = 0.098 MPa [Mpa] = Pressure at 10 mW. 2, container: Container is formed by the surface space for holding material components. Container generally consists of: cylinder, head (end cover), hair blue, bearings, take over, manhole and other components. 3. The total volume of the tank of the gas-filled and bladder-type water supply equipment, the adjustable water volume calculation and the number of pump start-up times: VZ = Vx / 1-αb Vs = βCqb / 4nmax Vo = Vs (β-1) αb) Weight of cylinder: W = 7.85Dnπhδ / 106 [Kg]. Head cutting reference size? = 1.2Dn + 2S + 2 times the straight edge height (25,40,50) mm