D - IN THE SIZING, COOLING TANK AND HAUL-OFF

 1.  Thin wall pipe in vacuum sizing collapsing, or jamming up, or       
     drawing down too thin.         
             
                 (a)  Too much vacuum creates a drag on sizing sleeve--reduce vacuum slightly
                      for smooth flow over sizing sleeve.

                 (b)  Too much distance between die and vacuum tank - two to three
                      inches should be a good clearance.

                 (c)  Material may be too hot out of die -reduce temperatures.

 2.  Nonuniform O.D. appearance(glossy and dull) or rough areas.       
            
            
          (a)  Possible "plateout" build-up (lubricants,pigments,etc.) on sizing sleeve.
                      Mineral spirits added dropwise on the hot melt just as it enters
                      vacuum sizing sleeve usually will remove most of the plateout. 

                 (b)  On large pipe, die and head may not be uniformly heated; generally
                      several hours are required for a “heat soak” for large mass of metal.
                      Also check heater bands and controllers.

 3.  O.D. not smooth and glossy - some pock marks.         
            
            

                  (a)  Not fully sized--increase vacuum,or increase air pressure on plug
                       to insure full contact with sizing sleeve. 

        4.  Pipe not round.    
             

                  (a)  Check for full sizing, as above,for sufficient vacuum or plug pressure.

                  (b)  Cooling water is not cold enough,and haul-off compresses pipe.  Use
                       chiller, or reduce haul-off pressure.

                  (c)  On large pipe, spray cooling, or cascade cooling is more efficient
                       than a flooded tank.

                  (d)  If this occurs after a long run, plug may be worn out.  Replace plug -
                       some use a double plug - one before and one after the haul-off, to
                       insure no loss in air pressure for sizing.                  

      
 5.  I.D. exhibits occasional tearing. 
             
             
           (a)  Plug too close to die--pulling material apart before it is cooled
                       sufficiently. Use longer chain---i.e.,75% of the cooling tank length.

                  (b)  If I.D. has no gloss, I.D. of material too cold - increase screw and
                       metering zone heat and also increase mandrel heat slightly, if available.

                  (c)  Haul-off speed too high - decrease speed slightly.

 
        6.  Pipe slips in haul-off, causing material to accumulate in sizing sleeve.         
             
             
    (a)  Increase air pressure on haul-off to provide a tighter grip on pipe.
                       If not corrected quickly, material build-up in sizing sleeve will not pass
                       over plug, so line will have to be broken and re-strung. Also, keep outer surface
                       of pipe dry before entering haul-off. Wet pipe will slip.
 

         7.  Pipe or profile too thin.   

 
                  (a)  Haul-off too fast--slow down slightly

         8.  Pipe or profile too thick.   

                  (a)  Haul-off too slow--speed up slightly.

E - IN THE SAW

 1.  Pipe or profile jamming.  
             
                                        
                       
               (a)  Saw blade too slow returning to original cut position.
                    Adjust speed of blade cut and return to occur before
                    saw table reaches end of forward travel. Adjust saw
                    table return to occur before next cut.(This applies
                    to both a chop saw and radial-cut/chamfer saw.)