Industry DOUBT: hood seals why "short-lived"

Licheng street Jian, who lives way out Chan raised a question: why does the cleaning hood, the situation will always appear seals need to be replaced? In this regard, the industry said, hood seals generally available 7-8 years time, does not require frequent replacement.
Since the cleaning hood Boli, so many workers will open the cleaning hood and recurrent say: hood inner ring is broken, needs to be replaced. Ms. Chen home hood needs cleaning, so you have a self-proclaimed professional cleaning hood cleaning man to the house, and later, the man picked up the two parts of a broken seal said it must be replaced. Ms. Chen did not think they picked a roll ring, said after the man measured a total length of 2.3 meters required, according to two meters denominated $ 120 cleaning fee plus 50 yuan, a total of 170 yuan. Later, however, Ms. Chen found the original home hood seals appear to be directly cut with scissors, and unnatural broken!
Chan not only encountered such a situation, an Ada please master home cleaning hood has also undergone a similar situation, hood cleaning to half of the workers who said seal is broken and must be replaced, and said seal my hood circle one foot to 35 yuan.
Many housewives do not understand kitchen appliances, so they are difficult to distinguish in the end tells the worker to clean the case is true or false, but do not know a ring of market pricing, so some unscrupulous cleaning workers in order to make money on the flicker housewife.
In this regard, many years engaged in electrical maintenance work, said Mr. Chen, hood seals generally available 7-8 years time, in the life does not require frequent replacement. Please people cleaning hood, 1, 2 years, frequent seal a bad phenomenon, not normal, may have been intentionally broken the cleaning staff, and may even put the prepared scrap into the apron of the machine, lied ring bad, so that the public money or replace, and hood seals prices of most 10 yuan per meter, even to replace all, the price is also within 50 yuan.