HAZOP Study- What is HAZOP?
(Note: To learn about HAZOP Study in detail and to get certified as a competent
person, please download or enroll online in the Abhisam HAZOP training course)
HAZOP is an acronym which is short for Hazard and Operability study and it
was first introduced many years ago by ICI, a multinational chemicals company,
based out of the UK. ICI no longer exists today as ICI (various parts have been
taken over by companies such as Huntsman and AkzoNobel), but the HAZOP study technique that they pioneered, continues to grow in
importance.
HAZOP is a risk assessment technique, used mainly in the chemical and process industries such as oil and gas,
refining, petrochemical, heavy chemicals, pharmaceutical and power generation
as well as industries such as mining too. HAZOP is one technique out of a group
of risk assessment techniques that form part of PHA (Process Hazard Analysis) .
Other techniques in PHA are FMEA (Failure Modes and Effects Analysis), LOPA
(Layer of Protection Analysis), HAZID (Hazard Identification), What-If analysis
and of course checklists. HAZOP is more subjective rather than quantitative.
The HAZOP technique is designed to
identify the intentions and deviations of a particular operation, called a
node. For example, a node may be a section of a plant that pumps liquid from a
storage tank to a reactor some distance away. Then in this node, the original
intention is identified (transporting liquid from the storage tank to the
reactor) and then all possible deviations are analyzed in detail. Some of these
deviations may result in accidents (for example if there is a reverse flow of
liquid from the reactor to the tank). This process (the HAZOP process) is known
as a HAZOP Study.
You may now appreciate that a HAZOP study should be done only by skilled
personnel. If an unskilled or untrained person carries out a HAZOP (using the
best software or no software), the chances of doing a bad HAZOP increase
manifold. Doing a bad HAZOP is worse than doing no HAZOP at all because a bad
HAZOP lulls people into a false sense of security, that their HAZOP study is
complete (and the recommendations are implemented and the plant is safe and
everybody lived happily ever after) when actually the opposite is true.
Thursday, April 25, 2013
HAZOP Process
HAZOP Process-what does it mean? The word HAZOP is an acronym for HAZard and Operability Study, which is a Risk Assessment technique used extensively in the process industries (such as Oil and Gas, Chemicals, Petrochemicals, Power, Pharma and others). The HAZOP Process is a structured method that is a part of a PHA (Process Hazard Analysis), in which one examines a small part of a plant or facility (called as a Node) using a set of Guide Words that seek to examine all the permutations and combinations possible in a particular plant operation. For example, if one is analyzing the flow of a liquid from say a day tank (lets call it Tank A) to another tank (say Tank B) then there are several things that can go wrong with this simple process, such as Low Flow, Reverse Flow, No Flow and so on. These guide words (Low, Reverse, No) are combined with a parameter (such as Flow) to generate possibilities of what could go wrong in the operation.
Then each combination gives us an opportunity to think what can happen. For example if the normal operation of the process is to transfer liquid from Tank A to Tank B, then Reverse Flow will be from Tank B to Tank A. Will this cause any problems? We then list all these problems under the heading of "consequences" and for each consequence we can think of a protective method by which this consequence can be avoided. Thus if we determine that reverse flow will have dangerous consequences, then we can prevent it by having a Non Return Valve in the line that connects Tank A to Tank B.
Thus each such condition will be evaluated for consequences and protective measures designed. If we do this diligently for the entire plant, we will have a much safer operation!
If you wish to know more about this HAZOP Process, you can download an excellent e-learning course here.
Then each combination gives us an opportunity to think what can happen. For example if the normal operation of the process is to transfer liquid from Tank A to Tank B, then Reverse Flow will be from Tank B to Tank A. Will this cause any problems? We then list all these problems under the heading of "consequences" and for each consequence we can think of a protective method by which this consequence can be avoided. Thus if we determine that reverse flow will have dangerous consequences, then we can prevent it by having a Non Return Valve in the line that connects Tank A to Tank B.
Thus each such condition will be evaluated for consequences and protective measures designed. If we do this diligently for the entire plant, we will have a much safer operation!
If you wish to know more about this HAZOP Process, you can download an excellent e-learning course here.
Subscribe to:
Posts (Atom)