while (my $line=<DATA>) {
  chomp $line;
  $line =~ s/\s+\|/\|/g; # note the "g" on the end.
  printf "\"%s\"\n",$line;
}
 
__END__
B-52         |P-51       | P-61
P-48         |B-1B        | JU-88
B-29         |ME-109


##</code><code>##

"B-52|P-51| P-61"
"P-48|B-1B| JU-88"
"B-29|ME-109"