write ascii file with pipe deliminate

private void createFlatFile(SqlDataAdaptor da)
    {
    DataTable dt = new DataTable();
    da.Fill(dt, "myTableName");
    DataView dv = dt.DefaultView;
    List<string> lines = new List<string>();
    foreach (DataRowView row in dv)
        {
        StringBuilder sb = new StringBuilder();
        string sep = "";
        for (int i = 0; i < dv.Table.Columns.Count; i++)
            {
            sb.Append(sep + row[i].ToString());
            sep = "|";
            }
        lines.Add(sb.ToString());
        }
    File.WriteAllLines(@"File:\Temp\myFlatFileWithSeperators.txt", lines.ToArray());
    }