Strainer Mesh size

Hello,

My question is about 40" size Y-Type strainer installed on cooling water pump suction line. On data sheet filtering element is defined as 20 mesh. But vendor is offering 8 mm perforation + 20 mesh. From existing plant we got information that perforation hole dia is 11 mm with square pitch or 15mm. Now I am confused between 8mm perforation and 20 mesh screen. Because we can't place 8mm hole in 20 mesh screen. Please clarify if any one have idea about it. I read on spirax sarco website perforated screen is used to support wire mesh cage.

Regards.

[Non-text portions of this message have been removed] Received on Mon Jan 05 11:49:00 2009