Foreword
With the development of oil drilling technology, well control technology more and more attention has been paid, on the performance and quality of well control equipment is also put forward higher requirements. Plug valve control device manual well as a control valve, it is an effective tool in the prevention of spray string, which is installed at the top of the column, when the overflow occurs, or a blowout, for closing string of central through hole, well fluids to prevent eye upward along the column of water spray, and supporting the use of the blowout preventer, is commonly used in the construction of underground work well control equipment. According to SY / T5525 standard, every six months to a qualified entity must be detected before they can continue to use.
1 of the problem
Because of the complex structure Plug valve, testing standards high, maintenance is difficult, has not carried out for Plug valve repair projects, resulting in nearly 30% of Plug valve scrapped each year in the testing process. To improve the ability of tapping the potential synergies and cost savings. We decided to analyze Plug valve, so as to solve the bottlenecks affecting production.
Two pairs Plug valve structure analysis
Plug valve by the body (housing), springs, upper and lower ball seat, ball, spin block, upper and lower ferrule, ring and seals and other components. Its body structure as a whole, all components must be loaded from the fitting hole, played the role of sealing and withstand high pressure.
Its sealing principle is supported by a spring at the tee and the ball pressed against the tee, the ball and the ball seat sealing surface in close contact, play a role in sealing.
Plug valve job stress is to rely on the under-card sets to complete, and is guaranteed to withstand high pressures and disassembly smooth, upper and lower card sets are used in the design of a larger-diameter openings structure, according to the order, Plug valve assembly body in the groove, and by the spring of upward thrust, upper and lower ferrule is pressed against the groove Plug valve body.
Step 3 disassembly analysis
Demolition, a large upward thrust of the spring, causing the upper and lower card sets difficult to remove, therefore, can only be pressed down firmly by one person sphere, another person will bite taken out of order. When installed, the ball must be pressed down to the bottom of the main body groove, then the card sets one by one into the groove, if done incorrectly, but also easy to make the ball pop up, there is insecurity.
By Plug valve structure analysis, we decided to develop a special tool Plug valve disassembly.
4 to propose and implement programs
4.1 Design type selection
By Plug valve principle structure analysis, the two sets of design (Table 1).
Therefore, for the implementation of the program selected Option II: Making multi-entry tool.
Select 4.2 design structure (Table 2)
By comparison, we decided to use the program for the implementation of two programs: the external design entry tool.
Implement a: design base
Recycled downhole tool joint base for processing, diameter and height are based on Plug valve connecting thread and highly determined, this will ensure that different types of Plug valve can bore into the base of the design, play a fixed Plug valve body purposes.
Embodiment 2: Design of supporting frame
Support frame using angle iron production, and its height is slightly greater than the height of Plug valve body, the upper portion is designed with openings communicating with the side, slightly larger than the diameter of the opening hole of the connecting rod diameter, and a connecting rod to take place flexible. The lower part of the support frame is hinged connection type activities, to take place when Plug valve, can be expanded on both sides of the support frame to ensure that Plug valve can take place freely and safely.
Implement three: design rotating mandrel
Rotating mandrel using a screw production, its role is to cooperate with the connecting rod nut, by turning the screw, push Plug valve downward movement of the ball, compression spring, and separated from the card holder to ensure that the upper and lower ferrule without outside influence, at the same time Plug valve to ensure the ball does not pop up when disassembly.
5 works
It uses a threaded rotatable propeller principle, an increase in its internal mandrel by rotating mandrel, resulting in downward thrust, compression ball and spring, the internal sleeve to lose its support, you can be up and down the card holder and the other part that disassembly. When assembled, in the reverse direction.
6 Evaluation
Plug valve disassembly after use special tools to disassemble and assemble efficiency increases, but only one person can easily operate. Not only improves maintenance efficiency, cost savings, and reduce labor intensity, increased security, Chuangxiao 168,000 yuan per year.
Table 1 2 sets of designs

Table 2 selection table design structure