Needlevalve: it is an important instrument measuring piping system components, mainly cut-off valve and ball valve, its purpose is to open or cut off access by pipeline.
针型阀：是仪表测量管路系统中重要组成部分，主要有截止阀和球阀，其功用是作开启或切断管道通路用。
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A new device for measuring run out error of needlevalve seat′s cone surface is proposed. The calculating and estimating methods of the error are also described in the paper.