The MF and HF Series use a multiple-point distributor system.  Smaller systems have two lower distributors while larger systems have six or more.  The plastic lower distributors have a 0.011 to 0.013 thousandths of an inch slot size to block resin loss. Internal piping is schedule 80 PVC with ABS distributor heads.   Open PVC pipe upper distributors are included in all MF and HF tanks.