pg_escape_bytea / pg_unescape_bytea (php) alternative in Rails?

Is there a built-in function that handles the problem of bitstreams in
postgresql? The problem occurs when the stream contains for example the
" character. Postgres will think that the string has ended with that
character. Is there a function that changes all such characters into
"\[ASCII-number]"? And the other way around when getting the stream
back from the database?