Detailed knowledge of the Strainers(二)

 Y-type Strainers

    The fine, porous nature of the filter element will create a larger pressure drop across the filter than that associated with the same size strainer; this must be given careful consideration when sizing such filters. In addition, filters are easily damaged by excessive flowrates, and the manufacturer's specified limits should not be exceeded.
    When the filter is used in steam or gas applications, a separator should be fitted upstream of the filter to remove any droplets of condensate held in suspension. In addition to improving the quality of the steam, this will prolong the life of the filter. A Y-type strainer should also be fitted upstream of the filter to remove all larger particles which would otherwise rapidly block the filter, increase the amount of cleaning required and reduce the life of the filter element. By installing pressure gauges either side of the filter, the pressure drop across the filter can be measured, which can then be used to identify when the filter requires cleaning. An alternative to this is to install a pressure switch on the downstream side of the filter. When the downstream pressure decreases below a set level, an alarm light can be switched on in a control room alerting an operator, who can then clean the filter.