Page 233 - Design of Simple and Robust Process Plants

Design of Simple and Robust Process Plants. J. L. Koolen 219
Copyright 2002 Wiley-VCH Verlag GmbH & Co. KGaA
ISBNs: 3-527-29784-7 (Hardback); 3-527-60047-7 (Electronic)

Chapter 6
Process Design Based on Reliability

6.1
Introduction

Reliability engineering and probabilistic risk assessment represent a discipline
which is becoming increasingly important in process design and operation in pro-
cess plants. It is not only the design philosophy statement,

Design for single reliable and robust components unless, justified economically or safety
wise

that demands reliability engineering techniques and a probabilistic assessment. In
an overview of the field of process design, operation and maintenance, it is possible
to identify the areas where these techniques are mostly applied, including the fol-
lowing:
1. Evaluate a process design on availability and reliability based on mechanical
failures rates of process equipment
2. Determine the optimal storage of feed and products based on the probability
of raw material supplies, product delivery requirements, and processing relia-
bility.
3. Evaluate the design of a chemical complex on its vulnerability resulting in
product availability against mechanical failures for different levels of redun-
dancy.
4. Evaluate process safeguarding systems, in particular instrumental protection
systems, on the probability of failure on demand and nuisance trips.
5. Develop a predictive maintenance program based on failure rates.
6. Evaluate optimal spare part stocks.
7. Evaluate the probability of an incident of a process plant through quantified
event and fault tree analysis.
The impact of reliability engineering is considerable, because many of the qualitative
design guidelines that are currently in use ± and often are quite conservative ± can
now be converted in quantitative approaches.