Facility Safety: Avoiding the 10 Most Common Design Errors
Authors: Johnstone James E. 
Published: March 2009

A lease operator received a call, early one morning, alerting him that one of his facilities was on fire. A storm blew through an area and in its wake; oil was reported in a creek that should have been safely inside of a tank surrounded by a berm. In another case, production was lost when a pipe fitting failed causing gas to blow to the atmosphere. These are all examples of real life events that happened because oil and gas production facilities were designed or installed incorrectly.

Many well sites, tank batteries and production facilities are at risk due to design or installation errors. These errors may have occurred when the facility was built or because the facility had been continually "added on" through the years. Design flaws can lead to equipment failure, lost production, injuries or harm to the environment.

Equipment reviews, looking for possible design problems, of thousands of onshore facilities have been made over the past five years. These facility inspections have taken place in thirteen different states and included varied sites: oil, gas, water, low- pressure, high-pressure, old and new. It was found that most design problems fell into several different categories.

One of the key results of these facility reviews has been the emergence of ten areas where facility operators can look to see if their facilities could be an accident waiting to happen. Many facilities examined had one or more design flaws that fell into these categories. Solutions to solving design problems have already been addressed by codes, good industry practices or regulations. Operators can greatly improve the safety of their facilities by looking for and correcting basic design errors discussed in this paper.

This paper reviews the ten key areas for facility operators to look at in order to make their facilities safer. Use of this paper should enable facility engineers, supervisors and workers to better identify "at risk" conditions and work to correct them.

10 Most Common Errors

1. Pressure "Spec Breaks" in Wrong Locations

One of the most commonly overlooked items when installing piping and equipment is making sure that all equipment can safely handle the pressures seen during normal and abnormal (or "upset") conditions. Many times, equipment appears to be selected to handle the normal or routine operating pressures. But, what happens when a valve is closed by mistake or if a meter plugs off? Piping and fittings improperly selected can easily be over pressured. A simple operating error or a failed piece of equipment can cause you to have a release or a major catastrophe when the right piping and fittings are not selected.

The definition of a specification break ("spec break") is a demarcation point when there is a change from one significant design (pressure or material) to another. Usually, the process and instrument drawings (P&IDs) will show a "spec break" for example between ANSI 150 and ANSI 300 equipment. Piping must be designed to safely contain the maximum pressure from any source (well, pump, compressor etc.) or be protected by a relief valve.