$re = '/<\w[^>]*>(?=<)|(?<=>)<\/\w[^>]*>/m';
$str = '{http://www.w3.org/2003/05/soap-envelope}Sender||BEA-382505 : OSB Validate action failed validation||<soap12-env:Detail xmlns:soap12-env="http://www.w3.org/2003/05/soap-envelope"><fault><errorCode xmlns:soap12-env="http://www.w3.org/2003/05/soap-envelope">BEA-382505</errorCode><reason>OSB Validate action failed validation</reason><details><ValidationFailureDetail><message>string value \'ROM\' is not a valid enumeration value for CountryAlpha3CodeSimpleType in namespace http://release.niem.gov/niem/codes/nga_genc/3.0/</message><xmlLocation><LocationCountryGENCCode>ROM</LocationCountryGENCCode></xmlLocation></ValidationFailureDetail></details><location><node>PipelinePairNode5</node><pipeline>PipelinePairNode5_request</pipeline><stage>ValidateMessage</stage><path>request-pipeline</path></location></fault></soap12-env:Detail>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php