▁In ▁addition ▁to ▁providing ▁gu idel ines ▁for ▁se al ▁selection , ▁API ▁ 6 8 2 ▁requires ▁qual ification ▁testing ▁by ▁the ▁se al ▁manufact ur ers . ▁▁ ▁API ▁ 6 8 2 ▁is ▁now ▁in ▁its ▁ 4 th ▁Edition ▁and ▁work ▁has ▁begun ▁on ▁ 5 th ▁Edition . ▁ ▁There ▁has ▁been ▁much ▁cons olid ation ▁in ▁the ▁mechanical ▁se al ▁industry . ▁ ▁Among ▁the ▁major ▁manufact ur ers : ▁ ▁John ▁C rane ▁( Smith s ▁Group ▁of ▁Great ▁Britain ) ▁includes ▁Se al ol ▁( Rot ary ), ▁F lex ib ox , ▁Saf ematic , ▁R op ac ; ▁▁ ▁Flow serve ▁includes ▁ ▁B W / IP ▁( B org - W ar ner ), ▁ ▁Dur am et all ic , ▁ ▁Five ▁ ▁Star , ▁Pacific ▁W iet z ; ▁▁ ▁E agle B urg mann ▁includes ▁E agle , ▁Burg mann . ▁ ▁Today , ▁in ▁addition ▁to ▁face ▁patterns ▁such ▁as ▁spir al ▁gro ov es ▁and ▁waves , ▁materials ▁have ▁been ▁developed ▁that ▁have ▁special ▁surfaces ▁to ▁promote ▁hyd rod ynamic ▁lift . ▁Las ers ▁can ▁be ▁used ▁to ▁et ch ▁micro scop ic , ▁performance ▁en han cing ▁text ures ▁on ▁the ▁surface ▁of ▁the ▁se al ▁face . ▁ ▁Pie zo elect ric ▁materials ▁and ▁electronic ▁controls ▁are ▁being ▁investig ated ▁for ▁creating ▁truly ▁cont roll able ▁se als . ▁ ▁The ▁application ▁of ▁special ized ▁se al ▁face ▁patterns , ▁surfaces , ▁and ▁controls ▁is