Smart control - valves and actuators

Improving operational efficiency may still be a challenge, but the industry is becoming smarter about ways to make it happen

Actuators, Control, Valves, ANALYSIS, Industry Trends

Improving operational efficiency may still be a challenge, but the industry is becoming smarter about ways to make it happen

At a time when big emphasis is being put on improving operations and tapping into the more difficult reserves, it is becoming more important that the flow of oil and gas is running uninterrupted.

An integral facet of any piping system, valves and actuators are crucial to achieving this. They control, regulate and direct the fluid that goes through it, which can often be both demanding and challenging.

“Most of the hydraulic systems designed for transporting fluids or gases work in complex operating conditions, which is why high-pressure valves and fittings are some of the key components for maintaining operations and production in the oil and gas industry,” says Sabharish Nandakumar, sales manager at Maximator.

Over the years, companies’ growing recognition of the importance of high quality valves has encouraged better scrutiny of the materials used, and the quality of products on the market.

“The trends we see in the market are the need for special materials like nickel based alloys, duplex or super duplex, as well as larger orifices and higher working pressures,” Nandakumar said, adding that in this region, demand for sour gas service valves and fittings is also increasing. Maximator’s ‘block and bleed’ and the ‘gauge and bleed’ valves are also high in demand, he said.

Another hit on the market is the metal seated, Triple Offset Valves (TOVs). According to Andrew Hoxley, marketing director at Pentair Flow Control Middle East, the TOVs have with zero leakage performance and are gaining popularity in all types of critical applications that were more traditionally associated with ball, gate and globe valves.

“Customers are attracted to the commercial benefits of the valve, which are driven by its size. Larger valves, such as TOVs, require less material compared to ball, gate and globe types. This lighter weight leads to reduced cost, not only with regard to material, but also relating to the infrastructure pipework configurations, as less piping support is required to hold the valve in position. There will therefore be a lighter load on the surrounding pipework.

“The TOV’s non-seat rubbing design, combined with its lighter weight, means it can be paired with a smaller actuator, allowing for a more economical selection and bringing aesthetic benefits. A further benefit is the TOV’s zero leakage capability, which makes the valve suitable for use in a number of critical high and low temperature applications, such as LNG service and hot gas applications.”

As products continue to evolve in qualities and types, the level of regulation has improved.

“Valve designs are bound by specifications and international code requirements. As a result, material technology is a key area of change for the major valve components, which are selected for their improved resistance to corrosion and erosion, and tailored to the relevant application,” Hoxley says.

“There are also advances in sealing technologies and materials which help to obtain improved fugitive emissions results. These provide a safer working environment for plant operators and help to reduce environmental impact of plant processes.”

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Suffice to say, the process of coming up with the best possible products is far from easy and has numerous factors to consider.

“The efficient work of valves mainly depends on the quality of the product and the know-how about the application and the sealing technology. Particularly, while working with different kinds of special materials, there are challenging conditions for the machining process and the quality of the surfaces. The design also needs to consider the modified mechanical properties,” Nandakumar explains.

One of the main challenges for customers is ensuring that the valve actuator is correctly selected for the type of valve it is required to actuate.

“The operational parameters of the valve must be adequately sized for the application in which it is used. For example, the actuator needs to be able to apply the right amount of torque to open the valve in the application for which it is intended, and at the correct speed of operation,” states Hoxley.

“Different valve types have different torque requirements. For instance, a butterfly valve has a lot less resistance than a ball valve during the complete sequence. Ensuring that the actuator can drive the valve correctly open and closed in a customer’s selected combination requires knowledge, experience and acceptance testing on the part of the suppliers,” he adds.

The problems is that customers often use two different suppliers when selecting a valve and actuator. Therefore, it is very important to make sure that the products are fit for purpose, both independently and when combined.

“There is a significant difference in valve and actuator selection for a simple task-automated on-off application. In non-critical applications, an open-to-close time of 30 seconds is acceptable, while a critical Emergency Shutdown (ESD) valve combination will require the valve to be closed in one or two seconds,” said Hoxley.

Undoubtedly, automation has become an indispensable component of actuators and valves. In addtion, smart technologies have further transformed the ways valves are being controlled, increasing personnel safety and allowing for an almost immediate response to any potential dangerous system malfunctions.

“Valves can be easily controlled as part of an integrated component of a computer-automated process; they can be activated from the safety of a control room, or wirelessly from a safe part of the plant. This increases operator safety by spending less time at the valve. In addition, operator safety can be further improved by reducing the physical requirements of manually opening and closing valves,” explains Hoxley.

“Advances in technology, such as Bluetooth or wireless connectivity options, allow operators to monitor valves’ vital signs. Through smart controls, operators can monitor actuator supply pressures, valve opening position, and system pressures and flows. They can even partially stroke (open and close) the valve to ensure that it is ready to operate.”

Another key driver behind valve automation is to facilitate ease of operations, says Mike Fynes, sales and marketing director at Smith Flow Control.

“Typically speaking, valves which are regularly used will require permanent dedicated automation. The challenge then arises when faced with operating valves that aren’t as frequently worked and may be subject to corrosion and stiff to operate,” he adds.

To contend with this issue, experts recommend portable valve actuators.

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“Portable valve actuators are effective on valves or gearboxes that require a high number of turns or are otherwise difficult to operate because of high torque.

Adverse climates, (sub-zero, tropical, dessert environments) where operation is more challenging, benefit the portable systems. Rather than the cost of a permanent dedicated actuator, portable valve actuators are a one-off investment. Individual reaction kits are mounted to each valve and the tool is moved between valves.

“This alleviates any possible muscular skeletal risk and is highly complementary to the human factors ergonomics (HFE) discipline,” says Fynes, adding that adopting HFE into the design and build of plants helps promote operational excellence.

In turn, Fynes suggests that operational excellence practices can improve machine or facility uptime, increase facility capacity, and lower maintenance and production costs.

“Although oil and gas companies are no strangers to this, there is a continual need to identify and mitigate environmental and process safety risks. Shell for example, sets Design and Engineering Practice publications, which highlight the central role of HFE.

Shell integrates human capabilities, limitations, requirements and expectations in the design of products, workplaces or work systems (plant or facility) resulting in the effective, efficient, safe and healthy functioning of human beings,” Fynes says.

Fact:
95-98% McKinsey estimates that world class oil and gas operators achieve a facility reliability of 95–98% and maintenance costs that are 30% lower than the industry average.

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