Click the series name you are looking for. Digital Catalog Model VCH41 VCH42 VCH410 VCHC40 Type Orifice diameter (mmo) 2 port valve N.C. 2 port valve N.O. 3 port valve Check valve Port size G3/4,1 G1/2 to 1 G3/4,1 o16 o17.5 o18 o16 Operation can be made from the toolbar at the center of the lower portion of the screen. Click here to display the contents. Click here to download the PDF file.