Blowdown Valve Sizing

blowdown valve
A valve generally used to continuously regulate concentration of solids in the boiler, not a drain valve. (Often called continuous blowdown.)

sizing
Form an estimate or rough judgment of someone or something
(sized) having a specified size
Alter or sort in terms of size or according to size
(sized) having the surface treated or coated with sizing
Estimate or measure something's dimensions
size: any glutinous material used to fill pores in surfaces or to stiffen fabrics; "size gives body to a fabric"