Instruments: [Weekly Question] Discussion question for Week 9 of 2011 (prizes for participants)
Thread Content
Instruments and meters: 【Question of the Week】Question for week 9 in 2011: After a vertical installation of a pneumatic ball valve (DN200\PN2.5, with steam as the medium), it was found that the connecting rod between the valve core and the actuator had deformed. People are discussing whether this is due to improper installation by the user or a quality issue; how would you handle such a problem if you encountered it? : ~. e7 ]; c1 B Note: 1 1) Respondents can receive up to 20 wealth rewards, and only responses that involve in-depth discussion will earn extra points! In principle, not more than 120 ； - {' m3 t5 N6 k% n; l5 P( ~2 x5 M 2）Thank you all for your active participation. 3) Please hide your replies; the method for doing this is at http://bbs.hcbbs.com/thread-492556-1-1.html. (No rewards will be given for any replies that are not hidden. ） -
This post was last edited by Baghdad on 2011-4-13 at 20:48. It’s probably a mounting issue; a support frame should be provided for the cylinder section. Prevent torsional deformation
This post was last edited by pengshiqiang on 2011-3-7 09:03. The DN200 valve is quite large, and its cylinder part is very heavy. To prevent the cylinder section from deforming under the effect of gravity, it should be supported during installation; if no support is provided, I believe it indicates improper installation. Fix the connecting rod and provide proper support at the same time. If the support is in place, I think it’s a quality issue with the valve; of course, when encountering such a problem, one should contact the valve manufacturer for repairs.
The last edit to this post was made by Baghdad on 2011-4-13 at 20:49. The DN200 valve isn’t that large either; it’s likely that there is an issue with the quality of the valve. Previously, I encountered a case where the stem of an old valve was deformed; the pin at the connection between the stem and the valve disc had broken, which caused the stem to shift and deform. It was a single-seat valve, and it was used for steam applications. This type of ball valve has not been used much in steam systems. In such situations, our technicians remove the valve, disassemble it to determine the cause of the problem; if it can be repaired ourselves, we do so, and if not, we send it back to the manufacturer for repair. Indeed, negotiations with the valve manufacturer are being carried out again due to quality issues with the valves.
This post was last edited by denghl on 2012-11-26 22:50. Learn*
One possible reason is an excessive pressure difference before and after the valve; improper operation by the process personnel (using a handwheel) could also be a factor, as well as issues such as jamming in the material, springs, valve core, valve stem, or valve seat.
This post was last edited by Baghdad on 2011-4-13 at 20:50. The issue is mainly related to the quality of the valves; since the valve’s own support structure is sufficient to bear its weight and maintain the structural integrity, there are two possible causes for this problem: first, the ball valve gets stuck, that is, there are impurities inside the valve core； Second, the quality of the valve itself is poor, resulting in poor alignment.
The last edit to this post was made by denghl on 2012-11-26 at 22:52. Pneumatic ball valves can be installed either horizontally or vertically. Deformation of the connecting rod between the valve core and the actuator may be due to installation issues or quality problems; it depends on the situation. If it’s a quality issue, contact the manufacturer~~~
The last edit to this post was made by Baghdad on 2011-4-13 at 20:51. I don’t think it can be attributed solely to quality issues; some manufacturers specify the installation method, and if it states that vertical installation is not allowed, then it’s due to improper installation. If the manufacturer does not provide any instructions, and errors occur after vertical installation, then it is the manufacturer’s fault. A bracket or similar device could be considered to solve such problems. For specific details, see the experts’ explanations