steam jacket breather valve

[proceng234]

Are any guidelines described related to tracing of breather valves?

For example,

An atmospheric water tank, should the breather be steam jacketed in western-EU climate (outside T < 0°C possible) to prevent freezing.

Thanks!

 

[gerhardl]

In a climate where components can freeze and be damaged or not function, it is common sense to provide secure heating and/or preventive isolation. Steam jacketing is not a cheap solution for any valve, and mostly used were the pipe itself is steam jacketed and the pipe jacketing plus isolation cannot protect the valve.

More common, for instance in Scandinavia, is heating by electrical heating cables, combined with protective insulation, not to loose the heat in the water itself.

 

[RVAmeche]

Heat tracing (heating via electrical cables) would be a more efficient and cheaper option, unless you happen to have steam immediately next to the tank.

 

[don1980]

All the major vendors of breather vents make a model that is jacketed, for applications in which process vapor can condense and freeze in the vent device. I think that's a better option than doing this with external heat tracing.

 

[proceng234]

Dear all,

Thanks for your answers. I am aware that several options are available at the different vendors.
Maybe I should rephrase my question: "Is it necessary to foresee a jacketed BV on a tank that contains water in a Western-EU climate? What are the guidelines? I cannot find anything in the API2000 related to this topic"

Thanks!

 

[gerhardl]

Hi Proceng234,
I dont believe there is any guidelines. Western-EU climate can be with, or without, fear of frost. Check local weather-records and authorities. Including France/UK and further north I would have recommended or directly prescribed protection, with a question mark for the southernmost part.

If it is fear of frost, and freezing will damage components or function, protection is sensibel and necessary. This can easily be done by a simple electrical heating cord/device and a termostat. Local companies can advice on solution and cost.

This is by far the cheapest way, if you do not have steam jacket or steam utilized directly at the tank, regardless of other advice.

The tank itself must be considered separately. Isolation, water temperature, circulation, heat in surroundings, max exposuretime to lowest temperature. If the tank already is provided with a steam jacket, the answer for your qestion of a steam jacket for the valve is simply yes.

(PS. I do shovel snow away to clear my front yard each winter).

 

[don1980]

The risk obstruction in the tank vent depends on the fluid in the tank as much as it does on the outside temperature. Some materials tend to crystallize at ambient temperature (e.g. napthalene). As trace amounts of vapor condense in the tank vent device, crystal formation grows until it impairs the functioning of the vent valve. In my experience, this is where jacketed/traced tank vents are used most often. Of course, these are special cases. The vast majority of tank vents don't need jacketing or heat tracing.