Plug valve structure improvement and strength check

December 16 14:06:08, 2022

Stopcock is a plug with a through hole as the opening and closing pieces, through the plug body and stem rotation to achieve the valve opening and closing action. Plug valve structure is simple, quick opening and closing, fluid resistance. This article made some improvements and calculations of the strength of plug Valves used in drilling. Plug the opening and closing member is a perforated cylinder, around the axis of rotation perpendicular to the channel, so as to achieve the purpose of opening and closing channels. Plug valves are mainly used to open and close the pipeline and equipment media purposes. Plug the main advantages are: For regular operation, opening and closing fast, lightweight. Small fluid resistance. Simple structure, relative size, light weight, easy maintenance. Sealing performance is not limited by the installation direction, the flow of media can be arbitrary. No vibration, low noise. However, the plug valves used in drilling often appear after closing the problem is not easy to open, this paper conducted a series of discussions and improvements. Plug valve structure improvements: The lower part of the valve opening the way to make the pressure on both sides of the basic balance, the valve is very easy to open and close, to solve the problems of the original plug valve. Improve the plug valve strength is calculated as follows: 1 shell reference stress calculation A, ball valve hole center section 3-3a, tensile stress concentration analysis A, ball valve section 3-3 a, stretching 2 .. "Chemical Equipment Design Manual "Chapter 5 Pressure Vessel Design, the maximum stress of a cylindrical shell hole is found at the point where the tangential direction of the radial hole edge is parallel to the circumferential direction. The stress concentration factor is 2.5, that is, the stress concentration factor Take 2.5. Yield near the stress concentration point to occur. But less than 2, so stability. b, to reverse the stress analysis of the openings in the pressure vessel design of Chapter 5 of "Chemical Equipment Design Manual", it can be seen that the thin-walled cylindrical shell with the pinholes subjected to the torsion action has the maximum tensile stress appearing on the cross-section of the hole edge and the shaft On the hole by the role of the cylindrical shell of its stress concentration factor of 4. Will not yield. c, the internal pressure p = 105MPa role of the "stress concentration factor manual" found that the cylinder wall open a small hole thick cylinder withstand internal pressure, available stress concentration factor A = 3.03

Rubber Joint

Flexible rubber soft joint is also called rubber joint, rubber flexible joint, soft joint, shock absorber, pipeline shock absorber, shock absorber throat, etc. It is a kind of high elasticity, high air tightness, medium resistance and weather resistance. The pipe joint is a hollow rubber product that acts as a flexible connection between metal pipes
Rubber soft joint products utilize the advantages of rubber's elasticity, high air tightness, medium resistance, weather resistance and radiation resistance. High pressure, high temperature mold vulcanization. It has high internal density, can withstand high pressure, and has good elastic deformation effect. Shock absorption, noise reduction, lightweight, non-toxic.
According to the shape, it is divided into: concentric and same diameter, concentric reducer, eccentric reducer.
According to the structure, it is divided into: single sphere, double sphere, elbow sphere.
According to the connection form, it is divided into: flange connection, threaded connection, threaded pipe flange connection.
Flange for connecting rubber joint: DIN BS ANSI JIS standard
Working pressure: 0.6Mpa, 1.0Mpa, 1.6Mpa, 2.5Mpa
Working temperature: -40 degrees to 80 degrees (also can process high temperature resistant rubber soft joints)
Material of main parts
Ball body: natural rubber, neoprene, butyl rubber, nitrile rubber, fluorine rubber, EPDM
Inner and outer lining: natural rubber, neoprene, butyl rubber, nitrile rubber, fluororubber, EPDM, PTFE
Main frame: Nylon cord
Booster ring: multi-strand copper-plated steel wire
Flanges: Cast, Forged Carbon Steel (Q235), Stainless Steel (201, 304, 316, 321), Plastic (PVC, PPC)
The flexible rubber soft joint solves the problem of different diameters when connecting metal pipes, and also has the effect of shock absorption and noise reduction, which can save pipe installation parts and save costs. It has the characteristics of high pressure resistance, good elasticity, large displacement, balanced pipeline deviation, vibration absorption, good noise reduction effect, and convenient installation. It is used in connection with pumps and valves, pipelines with large vibration, and pipelines with frequent changes in cold and heat.
Rubber soft joint products have high pressure resistance, good elasticity (axial and lateral angular displacement), noise reduction, light weight, shock absorption, easy installation, flexible use, easy replacement and maintenance, and have acid resistance, alkali resistance, oil resistance, etc. Features.
Can be widely used in water supply and drainage, circulating water, HVAC, fire protection, papermaking, pharmaceuticals, petrochemicals, ships, pumps, compressors, fans and other pipeline systems. The ordinary type is used to transport air, compressed air, water, seawater, oil, acid, alkali, etc. at -15℃~120℃. The special type is used to transport the above-mentioned medium or oil, concentrated acid and alkali, and solid materials above -30℃~250℃.
Applicable media: sea water, fresh water, hot and cold water, drinking water, domestic sewage, crude oil, fuel oil, lubricating oil, refined oil, air, gas, steam and granular powder.
The normal applicable medium for flexible rubber joints is ordinary water with a temperature of 0-60 °C. For special media such as oil, acid and alkali, high temperature and other corrosive and hard textures, the corresponding special-resistant material rubber joints should be selected. , and cannot be used blindly or generically.
When using or storing the flexible rubber joint, avoid high temperature, ozone, oil and acid-base environment. A sunshade frame should be built for pipes used outdoors or facing the sun and wind, and it is strictly forbidden to expose to the sun, rain, and wind erosion. The surface of the joint is strictly prohibited to be painted and wrapped with thermal insulation materials. Due to the aging problem of rubber products, it should be checked and replaced in time.

Rubber Joint,Expansion Rubber Joint,Rubber Joint Pipe,Flexible Rubber Joint Flange

Inner Mongolia Overseas.Trade co.,LTD , https://www.flangevalvejoint.com