... in producing saw pipes, oil pipes, ERW pipes, seamless steel pipes,elbow,reducer,tee,caps,flange,tube etc.. TYPES: elbows ... B2311/2312, GB12459-99elbow : 90D , 45D, 180D, LR , SR ,seamless pipe :A106 GR.B / A53 / API5LSIZE : 1/2"- 48" ... such as saw pipes, oil pipes, ERW pipes, seamless steel pipes,elbow,reducer,tee,caps,flange,tube etc...1. Butt weld ... be happy to give you details. steel 180 deg elbow