Tank design - use of FA with tank blanketing

[Valving]

I searched a lot but could find any specific information. I am supporting a client working on a treated crude oil storage tank in a desert area. V:20000 m3 . They will use tank blanketing system and considering to use PVRV and Emergency Vent.
What I want to ask, as far as I know API2000 6th edition encourages use of flame arrestors more.
Could you pls. share your comments if there is a need for use of FA for this application specially for exterior deflagration?

 

[gerhardl]

Some thoughts, not claiming to be an expert:

A blanketing system has the purpose of preventing one of the necessary elements for ignition to be present by replacing oxygen.

A flame arrestor has the purpose of preventing an already ignited flamefront to spread through pipelines or openings.

In this way the one does not exclude or replace 100% the other.

What is practical, usual and allowed depends on a number of factors.

As total protection of a plant or tankfarm in most cases must be certificated as protected by local authorities, what is the opinion of the local society/authority?

 

[Valving]

gerhardl thanks for input.
I found what I am searching with your below sentence
"In this way the one does not exclude or replace 100% the other"
I was just wondering if there is any points that prevents use of FA together with blanketing.
I dont think that the local authority is interfering much for this application , it is one of the arabic countries problematic lately.

Rgds

 

[gerhardl]

The short answer is no.

Later examples of larger oil catasthrophes demonstartes that human operators and engineers are capabeble of making a number of human errors that combined makes 'safe systems' able to fail.

A very simple risk or consequence analysis or consideration should be able to highlight if both systems are necessary or adviseable together.

(Possible sabotage or armed attack might be one of the risk considerations in your case?)

 

[proinwv2]

After reviewing the appropriateness of a FA, or any safety equipment, I would suggest that the implications of failure be considered and also look at the cost of an installed FA vs. the values of the equipment, the stored product, the facility and not least human life and safety.

I think we all know that pressures ore put on designers to keep the cost down, and those pressures are forgotten when it "hits the fan".


Paul

http://www.ostand.com