TM 5-3895-368-14&P the tunnel and the storage tank.  When de-drumming this valve must be partially closed to divert most  of  the  heat transfer   oil   flow   to   the   tunnel   coils,   but   must   not   be completely    closed.        Melted    asphalt    cement    that    is allowed to drop onto cool or cold coils in the storage tank will   quickly   solidify,   resulting   in   the   loss   of   time   and additional  consumption  of  energy  to  remelt  the  asphalt. After  de-drumming  operations  are  completed,  this  valve may be fully opened. e.      Outlet   Gate   Valve.      The   outlet   gate   valve (Figure  3-1),  located  on  the  upper  piping  connection  to the storage tank, is identical in construction to the tunnel inlet gate valve.  This valve is used to throttle the flow of heat  transfer  oil  through  the  melter,  providing  control  of the  temperature.    Opening  this  valve  fully  will  tend  to raise  the  temperature;  while  partial  closing  of  this  valve will restrict the flow and tend to lower the temperature. f.    Asphalt  Jacketed  Valve.    The  asphalt  jacketed valve (Figure 3-1) is a plug type, rotary valve, with cored jacket  for  the  flow  of  heat  transfer  oil  to  heat  the  valve assembly.    The  valve  stem  and  collar  provide  positive stops in the full open and full closed position.  For valve installation  shown,  the  valve  is  fully  open  when  lever  is straight   up   and   fully   closed   when   lever   is   horizontal, pointing away from the storage tank. WARNING WHEN OPENING THE DOORS, ALWAYS CHECK THAT THE RATCHET LOCK IS SET AND HOLDING  BEFORE  RELEASING  THE WINCH HANDLE. INJURY TO PERSONNEL  MAY  RESULT  IF  DOOR SHOULD DROP UNEXPECTEDLY. g.    Hand  Winch.    The  two  hand  winches  (front winch,  Figure 3-1) are used to open and close the tunnel doors   for   loading   and   unloading   barrels.      Crank   the handle clockwise to raise (open) the door.  The door will be held open when winch  handle  is  released.    To  lower (close)   the   door,   turn   the   winch   handle   in   a   counter- clockwise direction, until door is completely closed.  The winch  for  the  rear  discharge  door  is  located  on  the  rear of the storage tank near the right side of the melter. h.  Hoist Control Station.  The hoist control station (Figure 3-1) is a two-position, momentary contact, rocker switch with center "off/braked" position.    Depressing  the rocker switch on the upper side will raise the load, while depressing  the  lower  side  will  lower  the  load.    When changing   direction   of   travel   for   the   load,   release   the rocker switch completely to stop travel prior to depressing rocker for opposite direction. 3-2. Initial Start-Up. WARNING OPERATOR MUST WEAR PERSONAL PROTECTIVE EQUIPMENT WHILE WORKING WITH HOT ASPHALT. FULL   FACE   SHIELD,   LEATHER   OR RUBBER    SAFETY    SHOES,    HEAVY INSULATED GLOVES, AND PROTECTIVE    CLOTHING    SUCH    AS COVERALLS COVERING ALL EXPOSED SKIN OR ARMS AND LEGS. CAUTION Do  not  operate  the  asphalt  melter  in the  rain.    Operation  of  melter  during rain   may   cause   the   asphalt   to   boil and catch fire.  After  a  rain  or  during humid   conditions,   open   the   tunnel doors and dry the unit before operating.      Keep   the   heat   transfer piping system full to minimize condensation. a.  Inspect installation of melter unit and all piping for proper connections. b.    Refer  to  operating  instructions  of  heat  source plant,  and   start   heater.      Adjust   heater   as   required   to insure delivery of heat requirements of melter. c.  Close the asphalt jacketed valve. d.   Open  all  three  gate  valves  on  heat  transfer  oil piping.    Tunnel  inlet  and  outlet  gate  valves  should  be opened  fully,  with  the  storage  tank  inlet  valve  opened only half way. e.      Open   the   tunnel   front   door   and   using   the electric  hoist,  load  six  asphalt  drums,  open  end  on  low side,  on  load  ramp  of  the  tunnel.    Push  each  drum  as loaded to rear of tunnel with the barrel ram. NOTE Loading    of    drums    must    be    done quickly.    Asphalt  may  start  to  come out of the open drums and adhere to heat   coils,      preventing   their   being moved farther into the tunnel.  If  this happens,   close   the   door   and   allow asphalt    to    melt    completely    before proceeding to load melter. f.  When all drums are loaded, close the front door of tunnel and allow the asphalt to melt and drain into the storage tank. 3-2