To tell the truth from the false, you can smell it first: smell the water pipe for any peculiar smell. Parallel pipes are often mixed with recycled toxic plastics, which often have a pungent smell. Then look: look at the color, thickness and luster of the water pipe, and whether the outer wall of the pipe is marked with trademark, specification, temperature, pressure and production batch. There are three points to pay attention to: First, we should pay attention to the formal agent shop or the manufacturer with the pipe authorization sales book. Second, we should pay attention to whether the purchased pipes and fittings are produced by the same manufacturer. Third, we should pay attention to obtaining product service cards.