Braskem's petrochemical refinery near the town of Duque de Caxias is nestled amidst green hills less than an hour’s drive from Rio de Janeiro, Brazil. The sprawling site hosts several chemical plants involved in the production of raw materials and further processed chemical products including polypropylene and polyethylene. Valve World Americas visited the site to speak with Mr. Roberto Funger, Senior Inspection Engineer in the Maintenance Department during a recent visit. By Joanne McIntyre
The Braskem petrochemical site includes three different plants. The large UNIB 4 plant receives Ethane and propane from a neighbouring Petrobras site. This is processed through furnaces which refine the gas to produce the raw material for polyethylene and polypropylene. Polyethylene is produced in unit PE9 and polypropylene is produced in PP5. Small quantities of by-products such as gasoline are also produced on site.
In his role as Inspection Engineer in the Maintenance Department, Roberto is responsible for all inspections of the PP5 plant.
“Brazil has regulations in place defining the maintenance of equipment and the required inspections that must be performed,” he explains. “My responsibilities include carrying out inspections in PP5, as well as overseeing the Key Performance Indicators (KPIs) of all inspection teams including those working in units UNIB 4 and PE9.” In total the Braskem site employs ten full time inspectors and four engineers, including Roberto.
A Varied Role
“An important aspect of my role in maintaining the integrity of the plant is managing inspection schedules and maintenance planning,” explains Roberto. “It’s essential to ensure inspections are carried out at the correct times, as specified in our plan. Our next major site shutdown is scheduled in 2017. Another on-site two inspectors and I are together responsible for overseeing the inspection planning for the shutdown. We will study the inspections required, make recommendations and review all the data relating to the shutdown schedule.”
On a day-to-day basis Roberto has other priorities to as well. “My job includes some specific tasks relating to the procedures within the inspection department which I regularly review and discuss with our team, to identify any areas in which we can improve our daily work flow.”
Maintaining an Aging Plant
At just over twenty years old, Polyproylene plant PP5 is considered to be an ‘aging’ plant. “Other units on site such as PE9 and UNIB 4 are only 10 years old so present fewer problems in this respect,” explains Roberto.
While most of the plant is relatively easy to shut down and inspect, those equipments which are connected to the flare is a definite challenge, explains Roberts. “Six days are required to clean the flare pipe and the system connected to it. The flare is constantly burning, even when the plant is shut down, with the exception of the six days required to inspect and clean it. The cold section of the flare is constructed of special carbon steel for low temperatures to prevent it becoming brittle and cracking. The hot section of the flare – the tip – is manufactured of high temperature resistant material alloy 310.”
“The environmental climate around PP5 is not particularly aggressive. Although we are located just two kilometres from the Guanabara Bay the prevailing wind direction is favourable and we have few problems with external corrosion. Inside the PP5 plant the materials specified include stainless steels, not necessarily because of the corrosion fac- tor but to ensure the quality of the products.”
Volatile Polypropylene Market
“PP5 is shut down as required, for example if we have no raw material,” continues Roberto. “The current market situation also affects production; when the price is low it’s not cost effective to produce. As our product is a commodity the market is quite volatile and fluctuates a lot. Currently the market is very good for polypropylene so we are running 24 hours per day.”
“There is a very high demand for polypropylene at the moment in the United States; our production level is at the highest it’s been since I’ve worked here. As this affords us very few opportunities for inspection we need to plan very carefully because if we miss a window we don’t have another one. However this situation is only expected to last until next year when new polypropylene plants will be started up in Mexico and the USA. So we must make the most of the market while we can! As Brazils’ economy is in a recession most of our product is exported, although we hope that the local economic situation will improve over the next year.”
From Ball to Plug Valves
There are hundreds of valves in the PP5 plant, most of which are ball valves although the water system utilizes globe valves, explains Roberto. “Valves are specified in the same materials as the piping systems; normally the ball valves are manufactured in stainless steel with a PTFE seat.”
Asked if there are any particular issues with the valves that he needs to tackle, Roberto quickly identifies dust residues as a problem. “We have had a lot of problem with seat leakage. This is a significant issue for us as it requires replacement of the valve. The problem is generally caused by two factors. The first is age of the valve, particularly in the PP5 plant which is now over 20 years old. The second cause can be dust particles entering the production flow. This problem is particularly characteristic of certain parts of the process, although we have installed dust filters in the separation process.”
“In an effort to address this problem we have changed to using plug valves in some areas as these have been proven to be more efficient in dealing with dust/particle residue problems. From my experience in a previous job I know that plug valves perform much better than ball valves in some environments. However, as the original concept of the plant specified ball valves, it would be very expensive to change them all over. Therefore we are only changing to plug valves in particularly problematic areas. It’s a pity as I would love to change to plug valves throughout the whole plant, but it would be cost prohibitive.”
“In 2015 we also experienced a problem with gaskets in the bodies of ball valves which resulted in some leakage. This means we had to undergo a short shutdown and change the valves,” says Roberto.
The many (pneumatically) actuated valves on-site are maintained by a dedicated team who look after all instrumentation issues, including the actuators.
About Roberto Funger
Roberto is a mechanical engineer and worked as a maintenance engineer for Bayer Industries for 19 years. Roberto joined Braskem 3.5 years ago in his first role as an inspection engineer. Since 2005 he has also given yoga lessons three times a week after work in his home town of Petropolis, located in the mountains 65 km from Rio de Janeiro.