Maintaining pH Adjustment Equipment

pH adjustment systems consist of parts found in other locations of the treatment plant as well as the industrial site being served. Pumps are pumps and recorders are recorders. For the process to work, they must all function together as a system. The breakdown of one part will either shut the process down or necessitate manual operation. If certain parts are allowed to drift or to go out of calibration due to poor maintenance, process control will suffer. Because a chemical reaction is taking place and is usually being controlled by sensitive instrumentation, neutralization systems are trouble-prone and maintenance “hogs” (time consumers). An ounce of preventive maintenance is often worth a pound of breakdown maintenance.

Points of particular concern are:

1. Primary sensors such as level probes and pH probes,
2. Chemical feed pump bearings and seals,
3. Chemical feed pump stroke controllers or positioners,
4. Automatic valves and limit switches,
5. Screw feeders or vibrators for dry chemicals, and
6. Mixers.

Maintenance procedures should be set up and be as formal and detailed as practical. Most industrial sites are staffed to set up such programs. The operators should work with these people to see that a usable program is implemented. The treatment plant should maintain a complete set of drawings (updated) and equipment manuals. Operating logs showing all aspects of process, system and equipment operation should be maintained.