How about plastic pipe fittings?
Low temperature embrittlement (referred to in the standard drop test). The sample at 0 C in 30min refrigerator placed out immediately after falling freely in the cement ground, pipe diameter not greater than 75mm of falling height is 2m, more than 75mm fitting height of 1m, and then observe the surface of the pipe has no crack, intact products confirmed its the performance requirements.
The length or depth of the connecting part of the pipe (called the socket in the standard) is long enough. Irregular production of pipe fittings, in order to reduce costs, deliberately Jerry built, socket is generally shorter, so that in the future use of the joint leakage easily. If from the angle of safe use, the longer the socket depth, the more users can compare or actual measurement. From an economic point of view, however, the minimum socket depth is given in the standard. 5., pay attention to the purchase of pipe fittings and pipe matching issues. First try several times into the pipe inserted tube, should not feel difficult, but after inserted into not too loose for good.
Heat resistance (standard referred to as oven test). The good pipe is baked at the 150 - hour oven by the wall thickness
Click a few points to distinguish the quality of plastic pipe fittings, pipe 1. appearance. Good fitting outer wall is smooth, no thorns, no color, clear edges and neat, thick wall, feel thick.
