Lightning arrester is equipped in the 4" stainless steel water-type immersible motor.
Thermal protector and electron starter are also adopted. There are no centrifugal
switches or capacitances, which will avoid the mechanical loss, increase
the starting times and reduce the volume.

The stator is externally welded and internally lined with stainless steel, and is
also filled and sealed with epoxy resin. Then the products have such features as
good sealing performance, corrosion resistance, quick heat elimination, deep-water
pressure resistance, long life span and low cost.

The rotor takes the squirrel-cage type. The tank is molded with high quality aluminum
ingot or circumferentially welded with copper stripe and copper ends, so that
it is hard to distort or fracture and has good conductibility and high efficiency.
The sheet steel has gone through chemical treatments and won't rot. In addition,
footstep bearing is adopted that larger axial load can be borne.

The motor inside is lubricated and cooled with water, because water won't bring pollution
and special maintenance is unnecessary. The general dividing depth of this
pump can amount to 350 meters, which solves the internal problem of deep-water
activities and scientific research.