Having worked for several years with Saudi Aramco, and currently assigned as a project engineer covering capital programs, Mohanned W. Tarabzouni is a real expert when it comes to valves for oil and gas applications. During a recent conversation, Mr. Tarabzouni was kind enough to discuss his experiences in specifying and procuring valves for pipeline projects.
By David Sear
Q: Mr. Tarabzouni, let us suppose Saudi Aramco is planning to build another pipeline which of course will require a good number of valves. At what stages would you be involved?
A: The short answer: at all possible stages! My involvement will include, but is certainly not limited to, valve design, reviewing data sheets, material selection and application suitability. My role also includes ensuring the valves are properly commissioned and, throughout the lifetime of the asset, properly and safely operated and maintained. I cannot stress enough how important valve operation and maintenance really are, so these aspects are very essential parts of our day-to-day activities. My work therefore includes establishing preventative maintenance programs, developing repair guidelines and procedures, and also delivering training courses and demonstrations to field personnel in order to enhance their know-how, technical craftmanship and skill-sets.
What functions or duties can valves have in a pipeline?
Valves can be required for many applications. So, for example plant isolation, emergency shutdown, mainline sectionalizing, pig trap isolation, throttling and control, critical equipment isolation, safety and relief and so forth. This applies throughout the oil and gas industry. By this I mean upstream areas such as transmission pipelines, mid-stream such as cross-country lines and downstream in processing plants and refinery piping.
Can you indicate some of the more common valve sizes and pressure classes you work with?
Pipeline valves usually start from 4” and go on up to 56” in diameter. Pressure classes normally range from #150 and up to #1,500. Material selection is performed based on mainly service, temperature, pressure, and chemical properties of the medium. Carbon steel, stainless steel and in some cases duplex stainless steel are utilized per the need and as specifi ed internally in Saudi Aramco’s Standards and Specifications.
And would these be standard valves or engineered products?
Depending on the size, design and pipeline service, most of Saudi Aramco’s valves are custom made to specific requirements and specifications to ensure reliable and robust performance. Certain features may also be requested. An example is mandating a double isolation and bleed feature in pig trap isolation valves (Single piston effect X Double piston effect). Another requirement is calling for metal seated plug valves for pig trap kicker valves.
Does Saudi Aramco have a preference for gate or ball valves in oil & gas pipelines?
A general rule of thumb is to consider gate valves for liquid pipelines and ball valves in gas pipelines. However, the final decision is typically and thoroughly engineered to optimize the selection and ensure full compliance with the pipeline service. Looking at valve procurement I understand that many steps are typically required, such as specifications, quotations, etc.
Can you indicate your level of involvement?
In some cases where valves are needed on expedited basis, I get involved with the design basis and developing the data sheets to ensure that the required specifications are detailed and listed properly. Typical bidding and procurement activities are not part of our main involvement. On the other hand, myself and the team can also attend incoming valve deliveries as well as safe receiving inspection of valves. Valve procurement is of course a global business so I should note that Saudi Aramco has offices around the globe that can support procurement, inspection and other related activities. All offices work seamlessly together to ensure smooth procurement activities and prevent impacts on projects.
What are the real challenges when it comes to procurement?
Valves are built up of numerous parts and components. Ensuring that all the parts are properly made to an appropriate standard is essential if the manufacturer is to deliver a quality valve. I therefore see the main challenge as being the manufacturing processes. They must be properly executed while at the same time maintaining the highest level of safety and quality. Verifying the compliance of subcontractors and outsourced materials is also another challenge that accompanies valve manufacturing. Inspection, testing and quality control are part of the on-going efforts exerted to ensure a smooth supply chain.
Does Saudi Aramco work with an Approved Vendor List (AVL)?
Of course! Saudi Aramco has an AVL or AML which is reviewed periodically and checked to ensure suffi cient and effi cient valve makers are listed and available for any order. In fact, Saudi Aramco has its own Valves Standards Committee, and one of the committee’s tasks is to ensure a healthy and updated AVL. They look to check that requirements are met by capable and competent manufacturers.
Does the AVL comprise valve makers, stockists, or both?
Our AVL is primarily populated by valve makers. That is because pipeline valves are generally made to order and are not stock or shelf items as they typically require specific materials, design specifications, inspection, and testing activities, etc. Having said that, depending on the buyer’s requirements and specifications, some valves with typical or general applications are shelf items and can be procured from stockists to prevent delays and meet the project requirements in a timely manner.
Once a project has been completed, with all the valves properly installed and commissioned, how do you make sure that the valve engineers and technicians of the future will have ready access to all the data required to properly operate, service and maintain the valves?
Typically, all relevant information and specifications are stored through the projects team and fully handed over to the operating facility or end user as a pipeline operator. All data sheets, manuals and other related information are both digitally and manually stored in designated locations.
Summing up, what would you say is the real challenge in your work?
Our goal is to ensure we receive the right valve at the right cost at the right time. The main challenge in this is dealing with all the obstacles and unplanned events that can and do crop up during the entire valve supply chain cycle. That is why several entities from Saudi Aramco are always ready to provide support should the need arise. Depending on the project stage my Saudi Aramco colleagues may assist with design and engineering, logistics and delivery, installation, and construction, etc. Everyone will willingly cooperate to ensure projects are properly completed and in good time.