????? ???? A53 ?????? ??? ????? ??????

?? ????? ?????? A53 ???? ????? ???? Shijiazhuang Deye Piping Industries Co., Ltd. ?? ???? ???? ?????? ????? ?????? ??? ???? ???? ?? ????????? ???????? ????????. ????? ?? ?????? ??????? ??? ?????? ?? ?????? ASTM A53? ??? ?? ????? ??? ?????? ????? ????? ?????? ????? ??????? ???????? ??? ????? ??????? ???? ????? ?????? ?????? ?? ?????? ???????? ?? ?????? ????? ?? ??????? ?????? ???????? ???? ????? ????? ?????? A53 ????? ??? ?????? ????????? ??????? ???????? ????????. ????? ??????? ????? ?????? ?????? ??? ?????? ???????? ?????? ?????? ??????? ?????? ?????? ????? ?????? ?? ????? ???????? ???? ????? ????? ?????? A53 ????? ??? ???? ????? ?????? ????? ??? ?????? ????? ????????? ???????. ?? ???????? ?????? ?????? ????? ??????? ????? ????? ?????????? ??? ???? Shijiazhuang Deye Piping Industries Co., Ltd. ?????? ?????? ????? A53 Grate Pipe ????? ???????? ????????