Regarding anti-freezing

Just don’t close the heat-traced valve completely, and ensure the drain trap is in good condition, and the problem will be resolved. I have experience this time, so there won’t be any problems next time.

When new heating elements are put into use, there will be debris in the pipelines, which can lead to easier clogging of the heating elements; it is necessary to flush and replace the debris as much as possible. The strainer should be adjusted to an appropriate flow rate; it should not be too small. It is still necessary to conduct inspections, detect and address issues promptly, and find the appropriate opening degree for the heat tracing valve.

Winter anti-freezing and anti-condensation measures have always been a significant task. Starting in September of 2021, I began organizing the anti-freezing and anti-condensation efforts for that year. Based on last year’s experiences, a plan for this year’s measures was formulated, responsibilities were assigned, and the leaking valves in various branches of the steam main lines were replaced, as well as the drain valves on those main lines； 1. Rectifications made last year to address freezing and leakage issues, such as instruments that were damaged by freezing, pipelines affected by freezing, and the need to add heat tracing to the pipelines after renovation ； 2. Reconnecting the heating system: After being out of use for approximately half a year, almost a year in total, the heating hot water system had a considerable amount of debris accumulated within its pipes. Each pipe was reconnected one by one; it’s inevitable that welding slag would be present during the direct welding process for the new pipes. It’s sufficient to establish a connection on one side of the supply pipe. In the case of low-pressure pipes, any leaks can be easily detected during inspections ； 3. Rectify the deficiencies in insulation; even if there is heat tracing, the insulation effect is not up to standard, and in cold weather, those parts that should remain warm will freeze (in practice, this issue can be fully resolved after implementing a low-flow circulation system for the heat tracing) ； 4. The device is heated through internal circulation; each branch is inspected. Any leakage points are noted during the inspection process. Once a leak is found, it is repaired immediately, or all leaks can be addressed together after the inspections are completed. Since this year’s inspection period started early, there is plenty of time to repair each leak as it is found ； 5. The external piping systems generally have long heat tracing circuits, for which steam heat tracing is used. Ensure steam tracing supply is connected in all branches; inspect and replace any internal leakage valves; replace steam traps in critical areas ； 6. After the inspection, the system continued to operate in a low-flow mode; as the temperature dropped, the crew promptly opened the valves at all feed and return water stations to facilitate operation ； 7. Drain the low point of the fire protection steam system, replace the internally leaking valve, and drain at the low point ； 8. Steam fire suppression system: replace the internally leaking valve, replace the drain valve ； 9. Steam purging system, replace internally leaking valves, low-point venting ； 10. Adjustment of cooling water cross-connections for stationary and rotating equipment, as well as adjustment of inlet and outlet cross-connections for circulating water ； 11. Inspection of the heat tracing effect for fresh water, deoxygenated water, demineralized water, etc., within the unit ； 12. Inspection of the anti-freezing device for the sampler inside the unit ； 13. Establish inspection routes for heat tracing for team members and management personnel, and conduct inspections on a regular basis. I’ve outlined the main points: this year’s anti-freezing measures have been effective. A few minor issues have been identified; some instruments have frozen. These can be resolved by making adjustments to the heat tracing systems during shutdowns for maintenance. It’s still necessary to have spare valves for the heat tracing systems, so that they can be replaced if they get damaged in winter. To prevent freezing, I’ve prepared plenty of tees, jumpers, flexible hoses, and plastic sheets; so far I haven’t had to use them yet. I hope there won’t be extremely cold weather this year. The steam line’s steam traps generally need to be replaced once a year as a precaution. For long-distance heat tracing lines, the steam traps should be replaced when necessary – one shouldn’t risk losing an entire pipeline just because of one valve.

Expert! ! ! :victory: