prov:value
| - Valves and valve components, as well as conduit fittings and the like, using such material as a lining or coating have heretofore been described or suggested, for example, in the United States Pat. Nos. to Johnson (3,073,336), Chu (3,148,896), McFarland (3,205,113), Boteler (3,206,530), Keen (3,223,763), Yost (3,227,174), Lowrey (3,334,650), Schenck (3,438,388) and Schenck et al. (3,459,213).
|