TM 5-3895-374-24-2 ANGULAR ALIGNMENT Sleeve Type Elastomer Coupling Check     angular     alignment     with a micrometer or caliper.  Measure from the outside of the flange to the outside of the other at 90° intervals around the periphery of the coupling.  Determine the maximum and minimum dimensions.      DO   NOT   rotate   the coupling.  The difference between the maximum   and   minimum   must   not exceed 0.002 inches. Spring Grid Type Coupllng Use    a    spacer    bar    equal    in thickness to the normal coupling gap.    Insert  bar,  as  shown,  to same depth at 90° intervals and measure clearance between bar and    hub    face    with    a    feeler gauge. The difference in minimum and maximum measurements must not exceed 0.002 inches. PARALLEL ALIGNMENT Sleeve Type Elastomer Coupling Check parallel alignment by placing a    straightedge    across    the    two coupling   flanges   and   measuring the   maximum   offset   at   various points around the periphery of the coupling.      DO   NOT   rotate   the coupling.    If  the  maximum  offset exceeds  0.002  inches,  realign  the coupling. Spring Grid Type Coupling Align so that a straightedge rests   squarely   (or   within 0.002 inches) on both hubs as  shown  and  also  at  90° intervals around the periphery. D - Piping General Plastic dirt seals are installed in flanges before the pumps are shipped and must be removed before installation.  Pipes must   be   supported   independently   to   ensure   no   force   is exerted on the pump.  Piping should be al least as large as the pump flange size.  Guidelines for piping procedures are given  in  the  'Hydraulic  Institute  Standards”  and  should  be reviewed before pump installation. CAUTION In order to avoid stress build-up due to piping expansion when   handling   hot   liquids,   it   is   recommended   to   install compensation   in   both   suction   and   discharge   lines.      For example,  use  of  flexible  piping  or  a  pipe  loop  will  minimize pipe loads due to thermal expansion. E - Suction Piping Suction  piping  should  be  as  short  as  possible,  be  of ample  size  to  keep  friction  losses  as  low  as  possible,  and contain a minimum number of fittings.  A straight run of pipe (20 times the suction diameter) is recommended immediately before the pump suction.  Check layout against the possibility of  air  pockets  forming  in  the  suction  lines.    Suction  lines should be sized for a flow velocity of approximately 6 to 10 ft./sec.        On    new    piping    installations,    a    wire    screen (approximately 32 mesh) should be temporarily installed at the suction flange to prevent debris (ie:  weld slag, dirt, etc.) from entering  the  pump.    Remove  screen  after  several  hours  of system operation. F - Discharge Piping Discharge piping should contain both a globe valve and a check valve.  The globe valve is used for starting, stopping, and flow control.  Control flow on the discharge side only.  The check valve will prevent the liquid from flowing back through the pump from long or high pressure lines. G - Driver When  sizing  motor  consider  maximum  liquid  viscosity, specific gravity and desired pump operating range.  The draft created by a TEFC motor can reduce the temperature at the shaft  seal  and  bearing  housing.    The  lower  the  operating temperature, the longer the expected shaft seal and bearing life.  Coupling guards of the open type are preferred. SECTION III - OPERATION A Start-up Before initial pump start-up or after pump has been shut down for inspection, observe the following procedures: 1.    Pressure  test  the  system  for  possible  leakage. Maximum Test Pressure 300 PSIG. 2.    Check pump rotation.  As viewed from the driven end, the pump rotation is clockwise. 3.    Do not run pump dry.  Prime the suction line and pump.  Loosen vent plug (item 130).  Rotate the shaft  by  hand  to  allow  any  air  in  the  pump  to escape  through  the  vent  and  pump  discharge. Tighten   vent   plug   when   all   air   is   removed. CAUTION If pump is not completely vented,  the  air  trapped  in pump  will  cause  the  heat  transfer  oil  to  carbonize  at elevated  temperatures.    The  sharp  crystal-like  deposits formed, significantly reduce life of seal rings and shaft. (page 3 - 1143) Figure 3