This week at Emerson Global User’s Exchange, the key focus of the conference is “Inspiring Ingenuity”. Innovations big and small can touch everyone, and can make our world a better place to live in. Something as simple as sliced bread, or as complex a new nanotechnologies, it all can make a difference. At Emerson Exchange, all of these ideas, innovations and proven results come together and are shared, inspiring ingenuity for the future.
Together with URS, Applied Control is presenting on one such inspiring solution: a High Integrity Pressure Protection System. While this is one of thirty-plus focused on Plant Web applications, it currently is a top-three finalist for recievieng a solutions excellence award. The award will be handed out at the end of the week.
Here is a preview of their presentation, as gathered from an interview with URS prior to Emerson Exchange:
We are implementing integrated distributed process control and safety systems which includes a separate layer of protection called high integrity pressure protection safety systems (HIPPS) for both greenfield and brownfield midstream gas processing plants. For one specific project we implemented DeltaV with CHARMS I/O for a new gas plant. DeltaV and CHARMS are used on everything except motors, which were purchased as OEM packages with PLC’s. Our field instrument network has about 1000 I/O in total, and is nearly 100% HART. AMS is used to manage the health of the devices.
The HIPPS portion of the project is a DeltaV SIS consisting of a CHARMS Smart Logic Solver (CSLS) providing I/O processing for CHARMS I/O and SIL 3 capable logic solving. The HIPPS is a separate and independent layer and integrates with the plant DeltaV for viewing on a common console. “Integrated but separate” is our philosophy.
Conventional safety systems utilize pressure relief valves, rupture discs, and flares to prevent over-pressure conditions. These systems protect equipment by relieving fluid to reduce pressure. The HIPPS system utilizes pressure sensors, logic solvers and isolation valves to protect equipment by means of isolating equipment and piping systems from the pressure source (for gas or liquid feeds).
Out of the 1000 I/O installed in the plant, only 1% was applied for HIPPS (3 pressure transmitters, 2 DVC digital valve controllers, 2 solenoid valves and 4 limit switches, for a total of 11 devices). Our instruments, valves and controllers must come with reliability certifications that satisfy safety integrity level 3 (SIL3) when assembled as a system. We utilize Rosemount 2051 pressure transmitters with advanced diagnostics for additional integrity in the measurement, and FIELDVUE ValveLink software which provides diagnostics for partial stroke testing. Partial stroke testing allows our customers to extend scheduled plant outages by verifying the availability of the HIPPS during normal plant operations.
All requirements of IEC61508 are met for all of the field instrumentation and logic solver. That means each device/component we use has to meet the IEC61511standard for safety systems. Emerson and the Local Business Partner can provide all devices with 3rd party certification to meet EC61511 SIL3 requirements. This saved us a tremendous amount of time; if we were to engineer this solution we would typically have to go out to 3 different suppliers to find IEC61508 components for each “discipline” (measurement, control, valves). But through our LPB (Applied Controls), URS was able to write only one purchase order, and not pursue certifications for any components required for the IEC61511 SIL verification report. Our local business partner, Applied Controls, provided it all. Between the time saved getting 3 specifications, 3 purchase orders, contract management, and collecting all certifications and documents to produce the SIL verification report, we reduced engineering time nearly two thirds. We unloaded all of that onto Applied Controls with a single specification.
This is a greenfield plant, and the customer had a hard startup date. Gas plants have agreements determining when they begin to process gas, and there are heavy penalties if the plant is not started up on time. Having a single vendor (with certification) not only reduced engineering time; Applied Controls also provided an integrated FAT at their facility (instead of doing it on-site), saving a significant amount of time. Managing multiple suppliers is difficult, and we were able to quickly assemble and test the system and find problems before the system was delivered to the site. We estimate 8 weeks of engineering time was saved altogether enabling us to meet the startup date.
HIPPS reduces flare loading, provides additional protection of equipment compared to relief valves, and lowers the environmental impact of pressure venting. The reason is that the gas line is shut off – isolated from the plant – if it exceeds the design pressure. There are no relief valves opening and no flaring. The isolation system senses the pressure with the 2051 pressure transmitters (again two out of three voting and higher integrity measurement with advanced diagnostics), a logic solver in DeltaV SIS checks the validity of the pressure signals, and two valves in series are closed if pressure exceeds the target.
For this plant, the gas pipeline has a working pressure of 1250 psig. Our engineering package has a design pressure of 1100psig. The ability to install HIPPS was critical to the feasibility of this project, since we would have had to re-engineer the package for the higher pressure. The added cost of engineering, the higher cost of scaled-up equipment, and the 6 month delay in startup made the project unfeasible without the HIPPS. PlantWeb insured we were able to do this in a timely and safe fashion.
Stay tuned, we will share more of this store in a post later this week about how HIPPS impacted URS, their strategy and reasoning for selecting this system other other options, and their vision for the future.
URS Corporation is a leading provider of engineering, construction, and technical services for public agencies and private sector companies around the world. URS provides services for federal, oil and gas, infrastructure, power, and industrial projects and programs.