An internal trap drain with large volume/high mass water seal for improved absorption of pressure fluctuations and extended duration of seal against evaporation in low-use conditions. Includes adjustable height strainer and water seal-protected weep holes.

A joint device for drain pipes comprises a structural tube made of a rigid material and providing structural integrity to the joint device. The structural tube defines at least part of a drain passage of the joint device, a bottom portion of the structural tube having diametrical dimensions for complementary sealing engagement with a pipe of a drain network. An annular seal of resilient sealing material is integrally connected to an upper portion of the structural tube to define at least an inner surface of a portion of the drain passage of the joint device, the annular seal having inner diametrical dimensions for sealing engagement with a tailpiece slid downwardly into engagement with the joint device.

A multi-layer water sealing device, includes at least two layers of water seal sequentially arranged from top to bottom. An upper-layer water seal has a floating bell-shaped cover structure, and the floating bell-shaped cover structure includes a water sealing box and a floating bell-shaped cover arranged in the water sealing box. A lower-layer water seal is arranged in a drain pipe below the floating bell-shaped cover, and one side of the water sealing box is extended to form or connected to a communication cavity offset from the drain pipe. The floating bell-shaped cover correspondingly is extended to form or connected to a floating component floatable in the communication cavity and offset from the drain pipe.

A method of installing a drain fixture, the method comprising first installing a sub-floor plumbing system comprising a plumbing trap, a removable drain pipe, and a sleeve. Next, the method comprises connecting the plumbing trap and the removable drain pipe and sliding the sleeve over the removable drain pipe. Next, the method comprises building a flooring surface proximate to the plumbing trap, the removable drain pipe, and the sleeve. Then, the method comprises removing the removable drain pipe at least partly from the sleeve, cutting the removable drain pipe to the desired length, and re-inserting the removable drain pipe through the sleeve and into the plumbing trap.

A drain structure used for mounting in a pipe includes a ring wall, a bottom plate and a chamber, wherein at least one overflow hole mounted on the ring wall communicates with an inner ring wall and an outer ring wall. The overflow hole comprises a first opening and a second opening, wherein the first opening comprises a top edge, and the second opening comprises a bottom edge. A first horizontal surface passes through the top edge of the first opening, and a second horizontal surface passes through the bottom edge of the second opening, wherein the first horizontal surface is not higher than the second horizontal surface to form a first water tank between the second horizontal surface and the bottom plate. Liquid accumulated in the first water tank is able to prevent insects and gases in outdoors from entering indoors via the pipe.

A joint device for drain pipes comprises a structural tube made of a rigid material and providing structural integrity to the joint device. The structural tube defines at least part of a drain passage of the joint device, a bottom portion of the structural tube having diametrical dimensions for complementary sealing engagement with a pipe of a drain network. An annular seal of resilient sealing material is integrally connected to an upper portion of the structural tube to define at least an inner surface of a portion of the drain passage of the joint device, the annular seal having inner diametrical dimensions for sealing engagement with a tailpiece slid downwardly into engagement with the joint device.