City sewer smell sometimes emerge , and some urban residents suggest if the sealed manhole covers are workable? They think if using sealed manhole covers,the odors will not come out from the sewer , and thus make some help to purify urban air.
Starting point for people is good, but in fact this is a very wrong advice. Why do we say that?Because water in the sewer is made carries a wide variety of municipal waste, if the entire sewer is sealed,its ’s easily gathered inside the sewer gas , once lit , extremely prone to explosion. This will bring the entire city residents at risk. This is the reason why manhole covers will keep holes on the covers . Another important reason manhole covers holes left to play the drainage effect when it rains.
With the improvement of people ‘s living standards, there are a lot of families,who possess their own little garden, which also has manhole covers , in fact, in their own gardens among the manhole covers are also not completely sealed. If you have the seal , the best way is to pave a solid board , and then fill in the soil above , the above can grow some grass , so it looks more beautiful.
Of course , sealing manhole covers must be used in certain wellhead. For example, cable wellhead , you must use sealed covers. After sealing covers , rain will not flow , so the effective protection of cables and other facilities inside the wellhead . The kinds of sealed manhole covers are relatively more, not one where we go forth . We are here to talk about the current use of the more common double sealed manhole covers. What is double sealed covers, first seal is that covers the use the sealing rubber ,and the second seal is that there is a sealing cap under cover ,thus forming double seal manhole covers. The following double seal composite manhole covers are manufactured by our factory.