Change Comma Separated to Pipe

I am trying to customize an Electronic Interface. I need to have the txt. file in pipe separated format. Can anyone help me with the code to do this?
Here is the code I started with.
List<Func> orderedColExpressions = orderedExpressionProvider.GetOrderedColExpressions(row);

            foreach (var colExpression in orderedColExpressions)
                if (lFirst)
                    strDelim = string.Empty;
                else strDelim = ",";

                strValue = colExpression();

                ttOutFileLine.Line_out = ttOutFileLine.Line_out + strDelim + strValue;
                lFirst = false;

I tried this and it separated it but does not display the pipe in the data. I need it to display.

if (lFirst)
strDelim = string.Empty;
else strDelim = “|”;