Magnetic material selection of the basic understanding and unified, ndfeb material working temperature below 150 ℃, smco material working temperature below 250 ℃, for the micro pump can choose barium ferrite.Pump body metal, nonmetal material cent two kinds big.Stainless steel, metal, does not mean to all liquids are not rust, it is mainly used for compatible with process fluid and precious liquids, ultra pure liquid.Nonmetal is specially developed for corrosive applications.It is divided into two kinds of circumstances.One is the pure plastic pump, with pure polypropylene or vinyl fluoride thermoplastic molding.Such as the UK vanton CGM pump flow rate of 136 m3 / h, lift 84 m temperature (135 ℃), motor 32 kw power.Secondly, liner pump, is now popular a method of corrosion resistant pump lined with plastic.General pump body available malleable cast iron manufacturing, fep, pp, pfa, PVDF, etfe seamless lining.Called magnetix resulted the new series of mta without lining seal pump and other pump is the key advantage of application of its advanced pfa fluoropolymer lining, pfa with its unique widely the ability of resistance to chemical corrosion, etfe, PVDF is famous or other non-metallic materials.Adopts the patent technology, pressure casting membrane process, join the pfa lining thickness and uniform, compete with rotational molded.Used in high purity and high temperature fluid is more ideal.Iso pump ptfe lining the minimum thickness of 3 mm, with mortise pressure into the pump casing, pump casing made of borosilicate glass.Isolation cover is the key of seal parts, it will lead to the bursting of the fluid leak catastrophic harm.Single layer metal sealing cover a wide range of applications, the despite eddy current will generate heat energy loss, if using high strength, high resistance materials can limit the damage, such as: hartz alloy c – 4 (2.4610).Invented by taiani metal laminated isolation cover five countries patent, has been used in many design, its efficiency can reach 99%, transmission power 150 horsepower.Single layer ceramic zro2 (zro2) isolation cover, resistance to caustic solution, acid corrosion, high hardness and good sliding properties, and high mechanical strength and elasticity (e = 2 x 105 n/was), have been used to working pressure of 250 bar.But the ceramic cover thickness is bigger, can’t the plastic processing.In early 1999, the U.S. patent imo pump, the new isolation cover made of carbon fiber and epoxy resin, thickness of less than 2.8 mm, with stainless steel flange.31 bar is suitable for operating pressure, temperature 232 ℃, 407 nm transmission torque, power of 149 kw under 3600 r/min.Double isolation cover provided the space of double insurance and is available for testing.Japan iwaki mde approach based series pump double shield made from glass fiber reinforced plastic.Ansimag two-coating epoxy resin isolation cover for paper mill conveying alumina, magnetic drive pump running 2 years without replacing any parts.Isolation cover vulnerabilities of welding is structure and corrosion of sensitive source, advanced manufacture method is the plastic molding, such as deep drawing, spinning, spinning.Shaft and the sliding bearing manufactured by high wear resistance sic.Dry running according to the practice is not seal the omen of magnetic pump.Elaborate fluid balance design, the rear part of the sealing ring joint action with the impeller holes, balance the liquid axial thrust decrease the pressure of the impeller.Entrance to the prerotation when adjusting valve to prevent low flow, turbulence, ensure low flow operation.Bearing point optimizing design of two sintering sic bearings, shaft sleeve of the spiral groove washing and lubrication trunnion, help provide the assurance of dry running 30 min, allows the operator to have time to adjust system, return to normal operation, and avoid catastrophic damage.