Daido Steel has been granted a patent for a threaded connection for steel pipes. The connection includes a pin and a box, with both having annular shoulder surfaces, sealing surfaces, and thread parts. The shoulder surfaces of the pin and box incline in the direction of screwing the pin, with the pin’s inner circumferential edge diameter smaller than the box’s. The patent also specifies the thickness of the annular shoulder regions. GlobalData’s report on Daido Steel gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Daido Steel, Hydrogen fuel cells was a key innovation area identified from patents. Daido Steel's grant share as of September 2023 was 29%. Grant share is based on the ratio of number of grants to total number of patents.
Threaded connection for steel pipes with inclined shoulder surfaces
A recently granted patent (Publication Number: US11774014B2) describes a steel pipe threaded connection that includes a tubular pin and a tubular box. The pin has an annular shoulder surface, an annular sealing surface, and a male thread part, while the box has an annular shoulder surface, an annular sealing surface, and a female thread part. The shoulder surface of both the pin and the box is inclined in the direction of screwing the pin, and the inner circumferential edge of the pin's shoulder surface is smaller than that of the box's shoulder surface.
The patent also specifies that the annular pin shoulder region, which appears when the pin's shoulder surface is projected onto a plane perpendicular to the pipe axis, should have a thickness of 60% or more of the wall thickness of the pin's pipe body. Similarly, the annular box shoulder region, which appears when the box's shoulder surface is projected onto the same plane, should have a thickness of 20% or more and 45% or less of the wall thickness of the pin's pipe body.
Additionally, the patent claims that the feed angle of the shoulder surface of both the pin and the box with respect to the plane perpendicular to the pipe axis should be between 5° and 20°.
This patented steel pipe threaded connection design aims to provide improved sealing and stability during use. The inclined shoulder surfaces and the specific thickness requirements of the annular shoulder regions contribute to enhanced performance. The feed angle of the shoulder surfaces further enhances the connection's functionality. This innovation could potentially find applications in various industries that utilize steel pipe connections, such as oil and gas, construction, and infrastructure development.