▁and ▁g lands . ▁ ▁Single ▁and ▁multiple ▁se al ▁arrang ements ▁were ▁used ▁as ▁necessary ▁to ▁accomplish ▁the ▁required ▁performance . ▁ ▁In ▁ 1 9 5 7 , ▁Se al ol ▁introduced ▁the ▁edge ▁w eld ed ▁metal ▁bell ows ▁se al . ▁ ▁Pre viously , ▁metal ▁bell ows ▁se als ▁had ▁used ▁a ▁formed ▁bell ows ▁which ▁was ▁much ▁th icker ▁and ▁st iffer . ▁ ▁In ▁ 1 9 5 9 , ▁John ▁C . ▁Cop es ▁of ▁Bat on ▁Rou ge , ▁LA ▁file d ▁for ▁a ▁pat ent ▁on ▁a ▁split ▁se al ▁and ▁was ▁awarded ▁Pat ent ▁# 3 0 2 5 0 7 0 ▁in ▁ 1 9 6 2 . ▁ ▁In ▁the ▁Cop es ▁design , ▁only ▁the ▁faces ▁were ▁split . ▁ ▁Cop es ▁chose ▁to ▁provide ▁custom ▁split ▁se als ▁which ▁he ▁manufact ured ▁himself ▁so ▁very ▁few ▁of ▁his ▁split ▁se als ▁were ▁produced . ▁ ▁The ▁C lean ▁Air ▁Act ▁of ▁ 1 9 9 0 ▁placed ▁limits ▁on ▁fug itive ▁em issions ▁from ▁p umps . ▁ ▁Se al ▁manufact ur ers ▁respond ed ▁with ▁improved ▁designs ▁and ▁better ▁materials . ▁ ▁In ▁October , ▁ 1 9 9 4 , ▁the ▁American ▁Pet role um ▁Institute ▁released ▁API ▁Standard ▁ 6 8 2 , ▁" A ▁Sh aft ▁Se aling ▁Systems ▁for ▁Cent rif ug al ▁and ▁Rot ary ▁P umps ”. ▁ ▁This ▁standard ▁had ▁a ▁major ▁effect ▁on ▁the ▁se aling ▁industry . ▁