Producator de flanse din otel carbon ANSI B16.5, ASTM A05, ASTM A350, ASTM A694 F52, F56, F60, F65, F70, flanse WN, flanse LWN, flanse SW, flanse filetate, flanse oarbe, deci flanse, flanse de imbinare suprapusa, rf -^ flans Zhengzhou Huitong Pipeline Equipment Co., Ltd.