FILTERS AND STRAINERS
Miscellaneous Mechanical Components
Part C of Figure 24 shows a manifold steam strainer. This type of strainer is desirable where
space is limited, because it eliminates the use of separate strainers and their fittings. The cover
is located so that the strainer basket can be removed for cleaning.
Figure 24 Common Strainers
If the filter or strainer cannot be easily removed for cleaning, the system design will usually
include a flowpath for backwashing. The backwashing of precoated filters has already been
explained because it is more complex than a typical backwash. The intent of a backwash is to
flow liquid in the opposite direction of normal flow, creating a pressure that pushes the debris
off the strainer or filter. The debris is flushed to a waste tank or drain.
Normally, to establish a backwash lineup, the flowpath upstream of the inlet to the strainer or
filter is closed, the flow path downstream of the outlet is closed, and a drain flowpath is opened.