Unscrambling safety regulations

If you want to do it yourself, Hillman has some advice. “End-users must read the applicable manuals to determine how to implement the system to meet the SIL3 certification. It’s a ‘buyer-beware’ scenario. They must realize that TÜV certificates are one thing, but the information in the safety, installation, and implementation manuals dictate how the system must be implemented to meet the SIL level. These describe the restrictions and requirements to implement to the SIL level.  Those restrictions often represent additional configuration and cost to the end-user.

“For example, a safety manual may require that the end user add an external relay to the output of the safety system to meet SIL3. The relay provides an alternative means to de-energize the loop, and if it’s not implemented in that manner, then safety is jeopardized. But if it is implemented correctly, it adds to the total cost of that application.”

Lakowski adds, “While we see the entire spectrum of experience, when it comes to dealing with SIS, most customers are aware of the standards, but haven’t fully come to appreciate the requirements. Since IEC61511 is a performance standard, measures of performance are required. The good news/bad news is that some engineering is needed to develop the performance measures. In reality, there’s more work for engineers to do to implement this IEC standard than was the case in the old days of ‘cookbook’ or prescriptive standards. In every proposal that we send out involving smart SIS with DeltaV SIS, we break out the steps of work in the IEC61511 Safety Life Cycle.  There are more than 40 steps we recognize in the portion of the lifecycle normally associated with projects.”

	FIGURE 4: SINGLE-VENDOR SOLUTION
	Honeywell installed an integrated control and safety system for British Petroleum’s Clair offshore platform.

Vendors to the Rescue
For users who don’t know the difference between an MTBF and SIL 3, process control system vendors offer plenty of help. They will even take on the entire job. Simon Coleman, Clair project manager for British Petroleum, selected Honeywell to install an Integrated Control and Safety System for its Clair offshore platform (See Figure 4), located 75 kilometers west of the U.K.’s Shetland Isles.

“Honeywell engineers participated in SIL Safety Integrity studies to categorize the safety, environmental and commercial integrity level for every aspect of the platform,” explains Coleman. “Honeywell’s fire and gas engineers were involved with the EPC contractor and the Topsides 3D model to locate gas detectors, smoke and heat detectors, and fire and gas closed-circuit TV cameras. Abnormal Situation Management (ASM) standards were used in generating the HMI to minimize information displayed to the operator to safely operate the platform. This included an alarm minimization review, in which every alarm in the Clair system was reviewed, and uniquely identified with priority, cause, and remedial action.”

Coleman says working with one vendor is a huge benefit. “We don’t have two vendors supplying two different interfaces. This helps us avoid unnecessary communications, and makes graphics and displays consistent.”

Likewise, a systems integrator can help with installation. “We have folks that are trained in the workings and specifications of SIS systems, but we don’t engage in defining these systems, only in executing the plans of the owners,” says Cliff Speedy, project engineer at C&I Engineering in Louisville, Ky. “We’ll participate in the planning of the systems, but most of the real definition comes either from experts from the corporation or from hired SIS consultants. We’ve become real experts at estimating and installing these systems, rather than experts at defining them.”

Hillman adds that Honeywell also provides services that cover the entire safety lifecycle, or they will help you do it yourself.  “Our project engineers and our integration centers are certified to the TÜV international standards,” he says. “We’re approved by TÜV to train and certify to the safety standards, so end-users can design and install themselves. We host regular training classes, and are listed on the TÜV site as certified trainers. In addition, our development center, factory, and our project engineers are certified.”

Siemens does the same. “We offer advanced tools to assist the end user thru all critical phases of the safety lifecycle,” says Fialkowski. “We can provide front-end engineering services for HAZOP and SIL validations, we have ‘Centers of Excellence’ for the oil and gas and chemical industries, and we offer pre-certified safety designs in applications like burner management systems and fire and gas.”

Ged Farnaby, North American business development manager for the Safety Solutions Group of ABB says his company can help, too. “ABB has made it a priority to help customers with safety system implementations, and to ensure our internal compliance for these solutions,” he says. “We have numerous certified safety engineers worldwide, as well as dedicated Centers of Excellence for safety. We’ve worked with our quality and engineering groups to produce a set of guidelines and procedures to ensure that all safety systems are designed and delivered for full compliance to ANSI/ISA 84.00.01 2004 Part 1-3 (IEC 61511-3 Mod).”

In addition, Triconex and Invensys work together to help users. “Triconex and Invensys provide TÜV-certified engineering resources worldwide, which assist in the design, programming, implementation and installation of safety instrumented systems,” says Luis Duran of Triconex. “Beyond a stringent quality assurance scheme and best engineering practices, providing qualified personnel in safety matters is particularly important as experienced plant personnel are getting scarce.”

Laskowski adds, “In addition to classroom, on-site training, and e-learning courses, Emerson offers courses on SIS at its PlantWeb University online learning center. The courses provide fundamentals and practical tips for SIS planning, selection and implementation, plus information on basic SIS concepts, design and installation, operation and maintenance, safety standard compliance, and new SIS technologies.”

It probably would be beneficial to learn as much as you can about SIL, SIS and all the other safety regulations. But if you don’t have time, you can turn it all over to your process control vendor.