- 
				           		According to actual needs. there are circulating sub with casing thread and circulating sub with union thread.
						        										 	
						        					            	 根据需要可分为套管螺纹循环接头和油壬螺纹循环接头(全规格)。
								    				            	 youdao 
- 
				           		According to actual needs. there are circulating sub with casing thread and circulating sub with union thread.
						        										 	
						        					            	 根据需要可分为套管螺纹循环接头和油壬螺纹循环接头(全规格)。
								    				            	 youdao