Execution of HAZOP's (process safety)

HAZOP: Hazard and Operability Study.

Hazop; the standard method is also referred to as fault analysis for the identification and evaluation of process deviations.
The purpose of this study is to systematically analyze weaknesses in the process in terms of operability, safety, environment and health.

HAZOP studies are carried out in various engineering phases as well as with existing installations.
During the transfer of a concept design to a basic design the so-called Hazard Identification (HAZID) technique should be implemented. With the transfer of basic design to detail design of a process-implementation a "Hazard Assessment and Operability Study" (HAZOP) is advised. Ongoing operations benefit from HAZOP reviews or enhancements. The application of this study can be performed in a chemical-physical process or with regard to ongoing processes. Today a Hazop study is applicable to almost all industries where initially the HAZOPS were applied only in the (petro) chemical industry.

The HAZOP study focuses on the reliability of your installation.
The Hazop study is subject to a standard method in which failure scenarios of processes and systems are defined. Performing a HAZOP study is a joint performance teaming up an experienced HAZOP leader with production and technical management staff.
Analyzing any consequential effects is done on the basis of up-to-date Piping and Instrumentation Diagrams (P & IDs).

A HAZOP study for existing installations will include an analysis of previously undertaken actions. The study will examine the need to make adjustments to the current design.

The results of the HAZOP study will be presented in a report containing all the worksheets and a list of recommendations.

TMG International delivers both an experienced HAZOP team leader as well as a secretary in charge of capturing the discussions and outcome the HAZOP sessions.

As part of the Hazop-study a classification can be performed on the process.
The SIL (Safety Integrity Level) level for each component will be separately defined. The SIL level of the entire loop determines whether the process compliant with the SIL requirements.
SIL defines the reliability and safety of the process, it is a follow-up step of the Hazop-study, like the ATEX compliancy.

A high-risk-installation is protected by multiple layers of security, the so-called "lines of defense," the instrumental security is one of them. A SIL study verifies per process, component or measuring circuit, whether it meets the SIL requirements.

SIL

The classification knows four different levels, SIL1 t / m SIL4. The higher the rating, the more high-risk the monitored systems are, the more severe SIL requirements will be.

SIL is a part of the standards IEC 61508 and IEC 61511. The IEC 61511. These standards determine which processes should be systematically evaluated in order to identify what the probability is of a dangerous failure, and what might be the consequences of this dangerous failure.

Brief description of the parameters (for the symbols see the risk graph)

Effects:
C1 Slightly injured
C2 Serious injuries and / or death
C3 Multiple deaths
C4 Large number of deaths (disaster)

Presence:
F1 presence of someone in the danger area is less than 10% of the time.

F2 presence of someone in the danger area is more than 10% of the time.

Escaping:
P1 In more than 10% of the cases, it is possible to escape
P2 In less than 10% of cases it is possible to escape.

Frequency of the LOC (Loss of Containment) scenario:
W1 is a relatively low frequency (argument: the protection is therefore less)
W2 The default frequency for the failure of the schemes and operators
W3 A relatively high frequency (try to achieve a W2 level with a better design)