The issue of shaft rotation before equipment startup
Thread Content
The shaft turning of equipment (compressors, pumps, centrifuges, etc.) before startup is performed before power is applied, or after power is applied for the convenience of operation. Please explain based on your own actual situations.
If manual turning is used, it must be done before power is supplied, and it is necessary to confirm that the power source has been disconnected. If mechanical turning is to be used, power supply for mechanical turning may only be applied after manual turning has been performed successfully. Some turbine designs feature only mechanical (or hydraulic) turning gears (as is the case with some units of Hangzhou Steam Turbines), which requires the operation of both the lubricating oil pump and the turning gear oil pump. However, if it is not used for an extended period, the coupling must be disassembled and the shaft turned manually until everything is functioning properly before mechanical turning can be carried out.
Turning the turbine and powering it up shouldn’t have much of a direct relationship, right? In our factory, the machines are never powered off when parked; they are rotated using power once it’s supplied, and we don’t see anything wrong with that
In the units on the 3rd floor, wasn’t safety considered when manually turning the gears?
Under normal circumstances, to prevent accidental operation, the machine is turned manually first before power is supplied.
Reply to 1# Aiwenren: Intact spare pumps are rotated by hand after power is supplied. Unless your backup pump is under maintenance and there is a power outage.
Cranking has little to do with power supply. For ordinary hand-cranked pump units, there are two scenarios: 1. After repair, before powering on, crank the unit to check for any sticking issues before turning on the power. 2. For pumps that are always in standby mode, it is sufficient to turn them over as long as it is confirmed that they are not running; there is no need to shut down the power supply.
I believe that from the perspective of personal safety, regardless of the form of shaft turning operation, as long as people may come into contact with components that could be rotating at high speeds and there is a possibility of the equipment starting suddenly, it is necessary to cut off the power and apply locks. Don’t be afraid of trouble; ensuring the safety of workers is of top priority. It’s better to be prepared for the worst!
Reply to 8# liuxc: You said that turning the disk after power is cut off is safe. If the pump in operation at this time experiences a serious malfunction and must be stopped immediately, while the backup pump is not powered on and cannot be brought online in time, will you have enough time? It takes about 5–10 minutes just to contact the electricians to supply power. In actual production, standby pumps are rotated while still under voltage, so that they can be used at any time to ensure continuous production. (Unless your backup pump is under maintenance due to a power outage and cannot be used as a backup)
Based on the actual situation on our site, there is no connection between the two. If, as you say, the machine is turned over first and then power is supplied, are then all the backup pumps at your site powered off? I don’t think so. Normally, for a pump that has been overhauled, it is sufficient to turn it by hand before starting it to check for any sticking, and this has nothing to do with whether power is supplied or not. This is common sense
I can’t agree with what was said on floor 9. You’re worried that there won’t be enough time to start the backup pump during maintenance, which could affect production, but aren’t you afraid that you might forget there are people working on site when you think about using the backup pump, thus causing an accident? When faced with two evils, choose the lesser one! Standardized operations are necessary at all times! ! !