Questions about the fire scenario for Condensate Flash Drum

[wormhhh]

I need to size a PSV for a Condensate Flash Drum. I have some questions:

1)If the fluid is water, do I need to consider a fire scenario for relief valve and how?

2)In the equipment data sheet, the flash drum is shown as:"Insulation: Steel-banded". What does it really mean? Is it fire proof or non fire proof?

Many thanks.

 

[Latexman]

1) Is the Condensate Flash Drum (CFD) in an area where flammables or combustibles are stored or handled? Does a pipeline of flammables or combustibles pass through or overhead of the CFD area? If there is a leak in a nearby system of flammables or combustibles, can it affect the CFD and/or it's area?

2) It means the insulation on the CFD is held in place by steel bands. It probably has a weather barrier covering the insulation and steel bands, so it is not visible. It's a common construction technique. I think what you mean by "Is it fire proof or non fire proof?", is - will the insulation *system* retain it's integrity during a credible fire and the subsequent response of all fire protection systems, both automatic and manual? If so, then you may take a credit for reducing the heat input from the fire for sizing the relief device. The most important factors for this are the insulation material, the construction techniques, and how good has been it's maintenance. I've take credit for foam glass, calcium silicate, and mineral wool (not fiber glass). There may be others that are acceptable. Good construction techniques are multiple layers with staggered joints, adequate insulation supports or clips, SS bands, and a SS weather barrier. Again, there may be others that are acceptable. Good maintenance practices would mean to me that at anytime at least 95% of the area is covered. If over 5% is not covered, then additional fire protection methods are used to provide adequate protection. One of those methods could be to shutdown the process and remove all flammables. There may be others that are acceptable.

Good luck,
Latexman

 

[wormhhh]

Latexman,

Thx for your info.

 

[ddkm]

Latex,

Is there an online resource that talks about
a) Insulation Standards, plus also
b) General knowledge to the various Insulation materials available in the industry (eg: Mineral Wool, Foam Glass, etc)



---engineering your life---

 

[Latexman]

ddkm,

I have never looked for one, but there are probably several. Try a search with Google.

Good luck,
Latexman

 

[unclesyd]

A little food for thought.
Normal Expanded Calcium Silicate insulation covered with Aluminum and banded with Aluminum or SS banding is not fireproof. Cal Sil insulation when exposed to temperatures over 500°F looses essentially all its strength.

If you used Cal Sil the weather covering has to be SS with SS banding to get any kind of fire rating.

 

[ddkm]

uncle, thanks for the tip.

What is the advantage (or disadvantage) of calcium silicate over foam glass?

---engineering your life---

 

[unclesyd]

Here are some personal observations.

Most installers like the Cal Sil better.
It is easiest to form.
It is only dusty and doesn't stink
It will take more heat than Foamglas.
Some Cal Sil tops out at 1800°F with Foamglas at 950°F
Foamglas will take moisture better than Cal Sil.
It has somewhat better compressive strength.
Foamglas can be applied with mastic.
It is a little harder to apply Cal Sil.
Cal Sil is normally easier to remove replace.
Foamglas is good to much lower temperatures.

To get more information you need to compare the two data data sheet.

If you need to use a Cal Sil that has good high temperature strength take a look at "Super FireTemp" or one of the Firetemp products.

 

[djack77494]

Because of concerns about insulation performance during fire conditions, I would be inclined to NOT take credit for any insulation. Remember that besides being able to withstand the fire conditions without significant degradation, the insulation must also withstand fire-fighting efforts, including resisting strong jets of firewater. If you're not totally sure that your insulation is able to meet these criteria, assume it will not be effective/available during a fire.

Though Latexman hinted at it, let me try to expand a bit on the concern. You need to be concerned with an external fire (pool fire) unless your equipment is so located that such a fire may not occur. Whether or not you need be concerned is determined by the presence of flammable substances in the area, drainage in the vicinity, and elevation of the equipment above where a fire might occur. You should be concerned with a liquid filled or partially filled vessel because the liquid will absorb heat from the fire, vaporizing in the process. You must make provisions for safely venting the vapors generated. Vessels containing only vapors generally will overheat long before pressure builds substantially, but still should be evaluated.

HTH, Doug