2 replies to this topic

[dattatray kolte]

IN DEP 80.45.10.11 dection 3.9.2 point 1 it is said as

 

Overpressure protection (a relief device) is not required for small-capacity (< 500 L)
pressure vessels containing liquid that is not classed “very toxic”, and if the liquid has an
initial boiling point higher than the maximum ambient temperature, and if fire is the only
overpressure scenario.
2.

 

1. if i have a filter containing fluid which have boiling point more than ambient temperature & classified as non toxic & volume less than 500 liter.

 

FIre case will be applicable?

 

2. Same conditions as said above & only volume is more than 500 liter then fire case will be applicable?

What i want to say is should all criteria be followed for taking fire case as a credible scenario?

 

 

[ankur2061]

Kolte,

 

The most important thing that engineers tend to forget and which does not require referral to any standard or DEP is whether fire is a credible scenario. In simple words, can the equipment you are trying to provide overpressure protection get exposed to a pool fire? This is the fundamental point that all process engineers need to analyze before indiscriminately applying a fire case.

 

What if the equipment you are trying to protect does not lie in a fire zone?

 

What if there is no source of fuel to start an external fire?

 

What if adequate safeguards such as bunding or curbing is provided around the equipment which prevents any radiant heat impinging on the equipment from a pool fire outside the bund or curb for the equipment under scrutiny?

 

What if adequate drainage is provided to prevent any accumulation of a flammable liquid fuel that can cause a pool fire near the equipment under scrutiny?

 

All these questions need to be answered before a process engineer or a process safety specialist decides to provide an overpressure protection relief device considering a fire case.

 

Standards and design engineering practices do help in decision making but cannot substitute for experience and common sense. Any over reliance on standards and DEPs is a detriment to lateral thinking and to my chagrin this is what I see in a majority of young process engineers today.

 

Regards,

Ankur.

[akm1954mukherjee@gmail.com]

Very good. Outstanding.

 

I shall suggest to create a data bank, depositing therein all the experiences gained to facilitate sharing.

 

A K MUKHERJEE