Hi Ninad
It looks like the broken pipe character is outside the US-ASCII character set.
ASCII Code - The extended ASCII table
You can try using the ASCII character to see if it works or not:-
Header.fieldSeparator = '0xA6'
Check also the following thread that mentions the use of non US-ASCII character.
Content conversion - endSeparator and fieldSeparator with unusual separators
In particular, it mentions OSS note 1936206 - if you have the corrections in place, you can try using MessageTransformBean and specifying the encoding with the following additional parameter.
xml.fieldSeparator.encoding=ISO-8859-1
Rgds
Eng Swee