Box type non-negative-pressure variable frequency water supply equipment

The invention relates to box type non-negative-pressure variable frequency water supply equipment which overcomes the defect that an electromagnetic valve or an electrically operated valve must be used in the prior art. A flow double-direction conversion device of the box type non-negative-pressure variable frequency water supply equipment comprises a cylinder, an upper flange is arranged on the upper portion of the cylinder, a left flange is arranged on the left side of the cylinder, a right flange is arranged on the right side of the cylinder, a left reducing flange is arranged on the left flange, a right reducing flange is arranged on the right flange, a left positioning guiding plate is welded to a left reducing guiding section of the left reducing flange, a right positioning guiding plate is welded to a right reducing guiding section of the right reducing flange, a guiding rod is arranged on the left positioning guiding plate and the right positioning guiding plate, a seal ball is movably arranged, the guide rod penetrates through the seal ball, baffles are welded to the cylinder and located at the joint of the cylinder and the left flange and the joint of the cylinder and the right flange respectively, and rubber sealing gaskets are fixedly arranged between the corresponding baffle and the left flange and the corresponding baffle and the right flange. According to the box type non-negative-pressure variable frequency water supply equipment, a pure mechanical structure is adopted, the electromagnetic valve is not used, safety and reliability are achieved, and service life is prolonged.