TM 10-4320-303-13 Table 2-7.  Operator Preventive Maintenance Checks and Services for TWDS.  (Continued) Location Item No. Interval Item to Check/Service Procedure Not Fully Mission Capable if: 10-MILE HOSELINE STATION-CONT 7 Before Road Crossing Ensure road crossing guards Road crossing Guard are providing protection for guard is not the hose line.  If road providing crossing guard has collapsed protection to or hose line is damaged, the hose line. notify supervisor. 8 Before Pressure Relief Inspect valve for presence of Dirty pressure Valve grit, sand, or dirt.  If relief valve. dirty, clean using soft Pressure relief brush.  Inspect for damage or valve damaged. leaks.  If damaged or Class Class III leak. III leaks are present, notify supervisor. 9 Before Pressure-Reducing Inspect skid for cracks and Skid has cracks Valve Assembly damaged welds.  Inspect or damaged valves, lines, and assembly welds.  Valve for damage and leaks.  If and lines are skid is damaged, valves are damaged. damaged, or Class III leaks Isolation cock are present, notify valve(s) is supervisor.  Make sure closed.  Class isolation cock valves are III leak. open. 2-17