HAZOP Study 2

[10815L]

Hi,
Could any one explain the methodology for HAZOP study, which are key components required for HAZOP study.
Thanks

 

[Fzob]

Here is a pretty good overview of the HAZOP process

http://www.ntnu.no/ross/srt/slides/hazop.pdf

 

[10815L]

Thanks Fzob,
Its really nice materail for the study of Hazop.
Thanks

 

[knapee]

HAZOP(Hazard and Operability study) is most widely aceepted method to produces a report study to make your plant safe.
Hazard analysis consists of identifying the hazards and hazardous events. to preform the safety for process plant design, amd this techniques such as fault tree analysis (FTA), failure mode and effect analysis(FEMA) and HAZOP(you interesting), and many texts to describe each method.

Usaully SIL review may together with HAZOP, but other think that SIL determination be performed as
as separated study after HAZOP.

 

[knapee]

1. define the element
read simplified version of a P&ID

2 examination phase
The basis of Hazop is the ‘guideword examination’ of parts of a plant or system to find
credible deviations from the design intent. This is an inductive method because we are inducing’ changes to the intended working conditions and testing in our minds to see if
these changes produce any problematic effects.

3. identify element :
An element is defined in IEC 61882 as ‘constituent of a part which serves to identify the
part’s essential features’. The standard goes on to note that elements can include features
such as the material involved, the activity being carried out, the equipment employed etc. Material should be considered in a general sense and includes data, software etc’.
Any element in a part may be able to change in some way that will affect the operation
or safety of that part.

 

[mfelzien]

HAZOP (Hazard and Operability study), SIL (Safety INtegrity Level), LOPA (Layers of Protection Analysis).

First comes HAZOP which determines the possible dangerious deviations of the current design. Inputs are P&ID information, Cause effect diagrams. This step can be difficult but results in a database of risk ranking tables. After these dangerous deviations from the HAZOP are determined its them possible to determine the adequacy of the in place Safety Protective Layers (SPL's).

This is where SIL/LOPA come into play. This is aided by FTA (Fault Tree Analysis and other methods). (i.e. Mean Time between failure: 1/MTBF = probability of failure).

It's a world of acronyms and ambiguity so senior process engineers that have some previous experience should be in the loop (among others). As a good reference try:

AIChE's - GUIDELINES FOR HAZARD EVALUATION PROCEDURES by Battelle columbus division Center for chemical process safety.

I myself have not done much with HAZOP/SIL/LOPA but as the process engineer in our company, I have given talks about them to the process department in our company. I find the FTA analysis interesting.

 

[10815L]

Hi mfelzien,
Thanks your reply,Could you attach a copy of cause and effect sheet for just rerefernce.
Thanks

 

[mfelzien]

10815L,

The information I have is owned by the companies that payed for the work. So, I can't really post that. Sorry can't help.

 

[10815L]

Hi mfelzien,
Thanks for your input.
10815l