A sealing device having a positive and negative pressure resistant water seal protection function. The sealing device comprises a sleeve body; an opening and closing valve plate is rotatably connected to the lower end of the sleeve body; a negative pressure valve mechanism is arranged at a side portion of the sleeve body; the negative pressure valve mechanism comprises a groove body and a multifunctional cover; the groove body is of a bevel structure; a pressure conduction film is provided on the bevel of the groove body facing the inner side of the sleeve body; a pressure conduction body corresponding to the pressure conduction film is arranged in the groove body; a push rod of the pressure conduction body passes through the multifunctional cover in a connection fit with the groove body; the push rod works in conjunction with the opening and closing valve plate by means of a locking mechanism; and the multifunctional cover is provided with a gas pressure hole communicated with a sewer line. The sealing device can prevent negative pressure from damaging water seal.

A smart flush toilet apparatus provides dynamic control of a toilet flush length and/or a toilet flush water volume based on data collected from toilet paper dispenser sensors and/or toilet bowl displacement sensors. A toilet paper dispenser may be used to report toilet paper usage to resupply toilet paper.