<?php

$epText = "this is for text |XYZ and |XYZ and XYZ";
$find = '|XYZ';
$replace = "\n";
$epFormatedText = preg_replace(
    "/(?<!\\w)" . preg_quote($find) . "(?!\\w)/",
    $replace,
    $epText
  );
 echo $epFormatedText;