In the installation and maintenance of a PVC drainage system, pipe fittings are like "joints" connecting pipes. They are responsible for guiding water flow and connecting pipes. Choosing the right type and specifications of pipe fittings is directly related to the smoothness and stability of the drainage system. When many people face the various PVC pipe fittings on the shelf, they often make it difficult: "Which are the commonly used models? What size should be matched for different pipe fittings?" Today we will explain the commonly used types of PVC drain pipe fittings at one time, as well as the corresponding adaptation specifications, to help you quickly clarify your thoughts.

First of all, the most basic pipe fittings are direct heads (also called straight-through). Its function is very simple - to connect two PVC drain pipes of the same specification to extend the length of the pipe. For example, when the balcony drainage pipe at home is not long enough, two De110 PVC pipes can be connected with the direct head of De110. It should be noted here that the specifications of the direct head must be exactly the same as the outer diameter of the pipe. De50 pipes use De50 direct heads, and larger or smaller pipes cannot be sealed.

Next is the elbow, which is the core pipe fitting to change the direction of water flow. Common are 90-degree elbows and 45-degree elbows. 90-degree elbows are used for right-angle turns, such as when the toilet riser is turned into a horizontal pipe; 45-degree elbows are slow turns, which can reduce water flow resistance and are suitable for long-distance drainage pipe steering. What's more special is the trap - the elbow with water seal, which can keep a section of water in the pipe and prevent the odor of the sewer from stringing into the room. For example, the S-shaped trap (De50) used under the sink and the P-shaped trap (De110) used next to the toilet cannot be replaced by ordinary elbows, otherwise there may be unpleasant sewer smell in the home.

Then there is a tee, which is used to connect three pipes to achieve diversion or confluence. For example, if the main drain pipe (De110) of the bathroom wants to lead a branch pipe to the sink, the positive tee of the main pipe De110 and the branch pipe De75 will be used; if the main drain pipe (De160) of the roof drains to the balcony, the oblique tee (the branch pipe is 45 degrees from the main pipe) will be smoother. When choosing a tee, pay attention to the combination of specifications of "main pipe + branch pipe", which must match the outer diameter of the actual pipe. For example, if the branch pipe is De75, you cannot choose the tee of the branch pipe De50.

tee is an "upgraded version" of the tee, which can connect four pipes and is suitable for scenarios with multiple drainage points. For example, there are three drainage points in a bathroom: toilet (De110), sink (De75), and shower area (De75). With one main pipe De110 and two branch pipe De75 tee, these drainage can be aggregated into the main pipe.

In addition to connecting pipe fittings, fixed pipe fittings are also very important, such as pipe hoops (clamps), which are used to fix PVC pipes to walls or ceilings to prevent pipe displacement. Its specifications should also correspond to the outer diameter of the pipe. De110 pipes use De110 pipe hoop, which can make the pipe more stable after clamping.

There is also a floor drain, which is the "entrance" of the ground drainage, and the bathroom and balcony cannot do without it. Commonly used floor drain specifications are De50 (small area balcony) and De75 (bathroom). It should be noted that the interface of the floor drain must be the same as the outer diameter of the drain pipe - for example, the floor drain of De75 must be matched with the drain pipe of De75, otherwise the surface water may not be discharged.

Finally, there is the inspection port and the cleaning port, which are the pipe fittings for maintenance. The inspection port is installed on the riser, and one is installed every other floor to facilitate dredging the blockage in the riser; the cleaning port is installed at the end of the horizontal pipe to clean the debris in the horizontal pipe. Their specifications also correspond to the outer diameter of the pipe, and the De110 riser uses the De110 inspection port.

has said so much, and summarizes the selection points of PVC drain pipe fittings: first look at the "use" - is it connected, turned, diverted or fixed? Then look at the "specification" - the outer diameter of the pipe fittings should exactly match the outer diameter of the pipe. For example, to connect the De110 pipe, all the corresponding pipe fittings (direct head, elbow, tee) must be De110; to do water sealing, you must use a trap instead of an ordinary elbow.

In fact, the logic of PVC drain pipe fittings is not complicated. As long as you remember "type-to-specification", you can avoid most of the selection mistakes. The next time you choose a pipe fitting, you may wish to ask yourself two questions: "What do I need this pipe fitting for? What is the outer diameter of my pipe?" The answer is clear, and the pipe fitting is selected correctly.