I appeal to you, the audience of "Zen". For a long time I can not understand the reason for failure of water meters. Faulty water meters because of the dissolution of the plastic is very common. I hope together with you we will understand.
Our patient: Water meter SCC-15 "Betar" Mr. Chistopol. Hydrometer refused to work the second time. Following the verification.
We make a simple operation for removing the counter mechanism. Removing the retaining ring.
Removing the protective glass can be seen traces of corrosion.
On these pictures we see the uncertain effect of the fluid on the plastic counter mechanism.
Plastic corroded. One might think that the device did not work on the drinking water. And I consider how the process fluid.
Substance dissolving counter to the touch and smell like alkali. Unpleasant sensations remain on the fingers even if the rinse fingers with water.
I dismantled another counter with the same problem. Here we see the same picture, but on a smaller scale.
Where in the counter mechanism water gets? To analyze this "healthy" the instrument of the same production. Get to the internal fault counter can not. A metal retaining ring they strongly corroded.
Removing the retaining ring and an insulating cover.
Before us is the internal content of the "water" of the water meter.
Task:To find out from where the counter undefined substance dissolving plastic.
1) Dissolved, plastic counting mechanism.
2) Brass counter housing cover.
3) A silicone O-ring.
4) The magnetic field from the "magnetic coupling" (transmits rotation from the impeller counter mechanism, through the brass cap)
5) Hot water heated to 60 c. C followed by gradual cooling to room temperature.
Additionally: Possible stray currents. The hot water is likely presence of other undefined impurities.
The counter is set on a hot water pipe. Constant changes in temperature. Counter heated cools. It appears micropores in the silicone lining, possibly under the influence of "ground currents" corroded brass. The liquid falls on the metallic retaining ring. A process of oxidation. The substance comes into contact with plastic parts. Plastic "eaten away" plasticizer, which leads to the destruction of the counter mechanism.
Friends, why do you think this process is going on? I am confident in the audience "Zen" has versed in the physical and chemical processes. Waiting for an answer educated readers.
I hope the information was useful. From SW.Timofei Mikhailov. Share this article with those who want to break the brain. Knowledge is power !