Instrument maintenance in winter
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Last night, I was working on a flow meter during the night shift; the heating system inside the meter box was no longer functional, so it was assumed that the meter head had frozen. There was no steam available on site, so I used hot water to thaw the meter head. In less than a minute, the meter started to give readings, which indicated that there was heating in the pressure transfer tubes. Antifreeze was then poured around both sides of the meter head to prevent it from freezing. After that, antifreeze was added to ensure proper functioning under positive and negative pressures. It will be fine once the heating system in the meter box is restored in a few days. In winter in the north, there are many tasks related to instrument maintenance, most of which involve heating systems and antifreeze. In fact, if there are impurities in the antifreeze inside the pressure transfer tubes, its antifreezing effect is reduced; therefore, it’s necessary to replace the antifreeze before significant temperature drops occur. For those meters that don’t have antifreeze, it’s essential to ensure that the heating system works properly. Instrument maintenance workers work at night, and their efficiency is low, so it’s crucial to carry out the necessary preparations before temperatures drop
Instrument maintenance in winter is quite troublesome
Meters are most vulnerable to low temperatures in winter; it is necessary to take proper anti-freezing and insulation measures before such conditions occur.
Yes, you’re right! All involve checking the heating elements in advance, draining condensate, and checking the antifreeze. An instrument preventive maintenance plan should be carried out before winter every year.
We in the south have never seen pressure pipes equipped with antifreeze – won’t the antifreeze end up in the process pipelines?
My drum level gauge (double-chamber balance vessel) is located at the highest point; I checked the insulation and heating elements before the temperature dropped. It was insulated with layers upon layers, but it still froze when the low temperatures arrived – it’s a real headache.
It’s a peer! I think the steam drums are all at the top. Due to wind effects, if the drum itself is used for heating, galvanized sheets should be used to protect it from the wind, and it must be sealed properly; otherwise, during the coldest times of the year, any gaps could allow cold air to get in and cause freezing. If steam or heating is used, the temperature will be too high; since a large amount of heat is required in winter, the circulation will be poor, and it’s possible that the heating element itself will freeze as well. My suggestion is to extract heat from the boiler itself, use galvanized sheets for wind protection, but always keep the issue of vaporization in mind