The invention relates to a
foam pump, which is used to absorb liquid in a container and make the liquid spray out foam from a
nozzle. The shell is composed of a pressure head, a
screw cap and a cylinder. The shell includes a pressure head, an air valve, a main column, Large
piston,
screw cap, connecting rod, small
piston, cylinder, spring and valve. There is a network
pipe between the pressure head and the air valve, and the spring is provided between the main column and the base of the cylinder. Among them: a network
pipe extends into the pressure head sleeve from below Inside, the lower end of the network
pipe communicates with the air valve, and at least a filter screen is provided at the entrance of the network pipe; the air valve is a tubular structure, and the middle part is provided with a circular ring with a downward
peripheral edge and a convex edge, and the pressure head is against the top of the circular ring. An air inlet groove is arranged on the inner wall of the ring, and an exhaust groove is arranged on the inner wall of the tube below the air valve. Because the spring is placed in the
air chamber of the cylinder, it prevents it from contacting with chemical materials and prevents the spring from rusting; and because the large and small pistons can be unlinked, it provides sealing, and the design of the network tube makes the sprayed foam more uniform.