Take the tour!
The DIAMOND-SIS® is designed as a low-cost, stand-alone, non-PE logic solver for process industry applications. Rated for –30C to +75C and constructed using Class I Div II components, it can be installed in the process unit near the equipment under control, even under the harshest of conditions, thereby reducing implementation costs.
DIAMOND-SIS® provides high integrity and process reliability. It is available in single, dual, and triplicated channel configurations with on-line diagnostics, testing, and maintenance facilities. The single and dual channel systems are acceptable for SIL 2, while the triplicated channel system is certified by Factory Mutual to SIL 3. This means that the DIAMOND-SIS® can meet the fault tolerance and PFDavg requirements of any application.
Each channel receives an analog or digital process signal. Two field-adjustable setpoints allow shutdown to be executed for high and low process signals. Serial or hardwired communications are used to remotely display process variables and system alarms. With its 5 Amp output rating, the system can de-energize multiple final elements, including motor control circuits and/or solenoid operated valves. Manual reset, local or remote, ensures controlled process re-start after shutdown. Manual ESD, using a local or remote emergency shutdown button, can be supplied. System power is 24VDC, 110VAC, or 240VAC; and the DIAMOND-SIS® can be provided with redundant power supplies and/or UPS.
The DIAMOND-SIS® is designed to make testing as simple as possible. Test procedures are supplied with each system. By simulating the process variable signal, the trip circuit can be function tested from input to output. Each channel has a dedicated status indication on the front-panel to make testing and troubleshooting easy. The single channel package is provided with a bypass switch so that testing and maintenance can be performed online. The dual and triplicated channel packages do not require a bypass for testing or maintenance, but they can be provided as an option.
The DIAMOND-SIS® design allows repair/replacement of the trip modules without disconnecting wiring, reducing the potential for errors during maintenance.
The Safety Requirements Specification, including Safety Integrity Level (SIL) verification documentation, can be supplied as an option. This makes the DIAMOND-SIS® the perfect packaged solution to address low I/O SIS needs.
Diamond SIS:
Typical Applications:
API 521 and Code Case 2211 of ASME Section VIII, Division 1 and 2 allow the use of a Safety Instrumented System (SIS) in lieu of a pressure relief device, as long as the SIS meets or exceeds the protection provided by the pressure relief device. As SIS, their design must follow the international standard IEC 61511. These systems are often called high integrity protection systems, because the SIS must achieve high safety availability. In most cases, the logic solver must be IEC 61508 compliant to Safety Integrity Level (SIL) 3.
The DIAMOND-SIS® is designed as a low-cost, stand-alone, non-PE logic solver certified as fit for use in HIPS applications up to SIL 3. The 2oo3 voting assembly provides the end user with a fault tolerant logic solver that it is physically and functionally independent from the process control and safety instrumented system. This complete independence mimics that of traditional relief systems, where the failure of one relief valve does not disable any other relief valve. By eliminating the common cause associated multiple HIPS implemented in one safety PLC, the random and systematic failures are significantly reduced.SIS-TECH takes a very serious and holistic approach to lifecycle documentation management and has developed a software program to help manage IPS lifecycle documentation across the lifecycle from the initial Process Hazard Analysis through IPS component test and repairs in the field.
Click to view technical description in PDF format
Coker drum switching and de-heading poses challenges to safe and reliable operation of the Coker Unit. Safety issues are generally related to release of hydrocarbons to the atmosphere by either opening in an in-service drum and allowing hydrocarbons to enter an open drum. End users have often struggled with identifying the necessary Safety Instrumented Functions (SIF) to prevent these loss of containment events. Preventing these events by implementing the SIF’s in the valve control system PLC means the system is classified as a Safety Instrumented System (SIS) requiring that it be implemented in a safety rated PLC.
The DIAMOND SIS® Coker Drum Switching and De-Heading is a standalone SIS logic solver designed to receive key process variables that are used to determine when the drum is in-service or open. When preset conditions are not met the DIAMOND SIS® outputs prevent the opening of selected valves. Process inputs to the system are overhead pressure, overhead temperature and inlet temperature and outputs from the system are supplied to prevent opening of the vent, drain, top/bottom head, blowdown, overhead to fractionator and inlet feed.
-
This design greatly simplifies the SIS and allows the valve control system to be implemented in a non- safety rated PLC.
-
Each Coker drum is monitored and protected by a stand alone safety system.
- The failure, maintenance or testing of any one safety system does not affect the operation of the other drums.
Click to view technical description in PDF format
Coker drum de-heading poses challenges to safe and reliable operation of the Coker Unit. Safety issues are generally related to release of hydrocarbons to the atmosphere by opening the top or bottom head on an in-service drum. End users have often struggled with identifying the necessary Safety Instrumented Functions (SIF) to prevent these loss of containment events. Preventing these events by implementing the SIF’s in the de-heading control system PLC means the system is classified as a Safety Instrumented System (SIS) requiring that it be implemented in a safety rated PLC.
The DIAMOND SIS® Coker Drum De-Heading Safety System is a standalone SIS logic solver (suitable for up to SIL 3) designed to receive key process variables that are used to determine when the drum is in service. When preset conditions are not met the DIAMOND SIS® outputs prevent the de-heading of the top or bottom of the drum. Process inputs to the system are Overhead Pressure, Overhead Temperature and Inlet Temperature and outputs from the system are supplied to prevent opening of the Top/Bottom Head..
-
This design greatly simplifies the SIS and allows the valve control system to be implemented in a non- safety rated PLC.
-
Each Coker drum is monitored and protected by a stand alone safety system.
- The failure, maintenance or testing of any one safety system does not affect the operation of the other drums.
Click to view technical description in PDF format
High/low level events challenge the safe and reliable operation of terminals and tank farms. Liquid overfill, or high level, can result in vessel damage and/or release of hazardous chemicals to the environment. Low level can result in loss of suction to transfer pumps with the potential for pump damage and can pose significant hazards when floating roof tanks are used.
End users have often struggled with implementing the required Instrumented Safety Functions to prevent these events. The DIAMOND-SIS® is a stand alone SIS logic solver designed to receive level signals from switches or transmitters. When user-defined set points (high/low) are violated the DIAMOND-SIS® provides independent outputs to close isolation valve(s) and/or shut down transfer pumps.
Click to view technical description in PDF format
Chemical processing sometimes poses significant risk to personnel and the community. Some process risks can be significantly reduced through inherently safer design practices. The remaining risk is managed by engineered and administrative safeguards. An independent safety instrumented system (SIS) is installed when it is necessary to override the operation of the process equipment in order to prevent the process hazard from occurring. The SIS must be independent and separate from the control system unless the user intends to design and manage the entire system as an SIS (ANSI/ISA 84.00.01/IEC 61511 Clause 11.2.4).
Legacy control systems are generally not designed to meet SIS requirements. Unfortunately, during the early migration into digital controls, many users implemented their SISs within their process control systems. Many of these users have implemented or intend to implement open systems to support business and plant operations. They do not want to impose SIS design or management restrictions on their control systems. Consequently, many users are looking for an independent back-up system that meets the appropriate safety standards and connects easily to existing plant equipment.
Click to view technical description in PDF format
Boilers, heaters, and furnaces are considered critical equipment in most operating facilities, posing challenges to safe and reliable operation. Safety issues are generally related to burner light-off, loss of pass flow containment, and loss of flame. Even when safety is not a major concern, equipment criticality or replacement cost generally results in specification of protective functions to prevent equipment damage and downtime. The equipment reliability is also a high priority, making the avoidance of spurious trips a crucial design parameter.
The draft technical report ISA-TR84.00.05 Application of ANSI/ISA 84.00.01-2004 for Safety Instrumented Functions (SIFs) in Burner Management Systems (BMS) provides guidance on assessing which BMS protective functions should be implemented according to ANSI/ISA 84.00.01-2004 (IEC 61511). An analysis of the BMS logic solver often identifies deficiencies in its integrity and/or reliability, resulting in the need to upgrade it to achieve the required PFDavg and spurious trip rate.
Click to view technical description in PDF format
The DIAMOND-SIS® SMART BMS builds upon our base BMS package and provides an enhanced operator interface using general purpose PLC technology. The safety trip functionality of the DIAMOND-SIS® SMART BMS continues to use the Model 340 Alarm Module. This trip amplifier functions as an analog or discrete relay and can achieve SIL 3 performance depending on redundancy and voting. The Model 340 Alarm Modules provide step-by-step Purge, Pilot & Main Burner permissive, light-off sequencing, and safe-bypass facilities.
The diagnostic and communication functionality of the DIAMOND-SIS® SMART BMS is independent of the trip amplifier and is provided by a general purpose PLC. The PLC is not safety related, but provides system fault status to field and remote displays. Fault alarms include First Out Trip Alarm, transmitter failure, BMS sequence interrupt and deviation alarm.
Click to view technical description in PDF format
