4.8　Filter

4.8.1　The installation of filters shall comply with the following requirements:

1　The longitudinal and horizontal center lines shall be adjusted，and the measurement by plumb wire should be carried out，with the allowable deviation of 10.0mm.

2　The elevation shall be adjusted，and the measurement by optical instrument or ruler should be carried out，with the allowable deviation of±10.0mm.

3　The levelness or verticality shall be adjusted，and the measurement by leveler or suspension wire should be carried out，with the allowable deviation of 3.0/1000 for vacuum belt filter and 1.5/1000 for electric back-flush filter.