管道壁厚的增加直接带来的性能的提升，比如：工作压力*，刚性增强，线性膨胀系数降低，耐温性能提高等等。

The increase of pipe wall thickness directly improves the performance， such as the increase of working pressure， the increase of rigidity， the decrease of linear expansion coefficient， the improveme*f temperature resistance and so on.

水路和电路不要同槽，如果发生漏水，或者产生冷凝水时，容易浸泡到电线，这是非常危险的，好相距10cm以上。如果有水电交叉的时候，水下电上。

Different hydropower tanks

Water circuit and circuit should not be the same as the groove. If water leakage or condensate water is produced， it is easy to soak i* the wire. This"s very dangerous，PVC管业制造， and it is better to be more than 10cm apart. If there is a water and electricity crossing， the underwater power is on.

目前，法兰连接中大的问题主要是法兰本身不合格和法兰连接不合格。

现在市场上销售的一些法兰存在的质量问题有：

①法兰的钢材不合格，耐压强度较低，在使用若干个月或若干个年后，出现渗水。

②法兰的螺栓孔外缘距法兰的边缘太小，小于5mm，崇明PVC管业，在螺栓紧固时，易使法兰边缘。

At present， the major problems in flange connection are the unqualified flange itself and the flange connection is unqualified.

Some of the quality problems of the flange sold in the market are as follows:

① The flange steel is unqualified and the pressure resistance is low. After several months or years of use，PVC管业生产， water seepage occurs.

② The outer edge of bolt hole of flange is too *all from the flange edge， less than 5mm. When the bolts are tightened， it is easy to make the flange edge.