TABLE 6-1 (Cont'd) Item Problem Cause Action Aluminum gate valves (Cont'd) Leak at gland(Cont'd) Scored stem 1.  Replace valve. *    2.        Replace    stem    and inspect   entire   valve.      Test and reissue. Valve will not hold pressure Scored or cracked seats 1.  Replace valve. *    2.        Replace    seats    and inspect   entire   valve.      Test and reissue. Scored or broken disc 1.  Replace valve. *    2.        Replace    gate    and inspect   entire   valve.      Test and reissue. Broken upper stem or lower stem threading 1.  Replace valve. * 2. Overhaul valve completely  replacing  stems. Test and reissue. Valve will not hold pressure Distorted body Replace valve. Valve body leaks Cracked or broken body Replace valve. Ball valves Leak at gland Loose packing Tighten gland nut. Worn packing Repack. Badly worn packing Depressure and repack. Valve will not hold pressure Worn   or   damaged   ball   or seats 1.  Replace. *   2.      Overhaul,   replacing ball   and   seats.      Test   and reissue. 6-27