How To Get Sil Certification

1. What is a SIS?
A SIS is a Rubber Instrumented System. It is designed to prevent or mitigate hazardous events by taking the process to a safety state when predetermined atmospheric condition are violated. A SIS is composed of a combination of logic solver(s), sensor(s), and final element(south). Other common terms for SISs are safety interlock systems, emergency shutdown systems (ESD), and safety shutdown systems (SSD). A Sis tin can be one or more Safety Instrumented Functions (SIF).

2. What is a SIF?
SIF stands for Prophylactic Instrumented Role. A SIF is designed to forbid or mitigate a hazardous event by taking a procedure to a tolerable adventure level. A SIF is composed of a combination of logic solver(s), sensor(s), and final chemical element(s). A SIF has an assigned SIL level depending on the corporeality of adventure that needs to be reduced. Ane or more than SIFs comprise a SIS.

iii. What is SIL?
SIL stands for Rubber Integrity Level. A SIL is a measure of safe system functioning, or probability of failure on demand (PFD) for a SIF or Sis. In that location are 4 discrete integrity levels associated with SIL. The higher the SIL level, the lower the probability of failure on need for the safety system and the better the system operation. It is important to likewise note that as the SIL level increases, typically the cost and complexity of the system likewise increment.

A SIL level applies to an entire system. Individual products or components practice not have SIL ratings. SIL levels are used when implementing a SIF that must reduce an existing intolerable process risk level to a tolerable risk range.

iv. What does functional safety mean?
Functional safety is a term used to describe the safety system that is dependent on the correct functioning of the logic solver, sensors, and terminal elements to achieve the desired chance reduction level. Functional safety is achieved when every SIF is successfully carried out and the process risk is reduced to the desired level.

5. Why were the ANSI/ISA 84, IEC 61508, and IEC 61511 standards developed?
The standards were a natural evolution for the need to reduce procedure hazard and improve safety through a more than formalized and quantifiable methodology. Additionally, and specifically for IEC 61508, as the application and usage of software has evolved and proliferated, there was an increased need to develop a standard to guide arrangement / product designers and developers in what they needed to do to ensure and "merits" that their systems / products were acceptably condom for their intended uses.
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6. When do I demand a SIF or a Sister?
The philosophy of the standards suggests that a SIS or SIF should be implemented only if there is no other non-instrumented way of fairly eliminating or mitigating procedure risk. Specifically, the ANSI/ISA-84.00.01-2004 (IEC 61511 Mod) recommends a multi-disciplined squad approach that follows the Safe Lifecycle, conducts a procedure gamble analysis, designs a variety of layers of protection (i.e., LOPA), and finally implements a Sister when a hazardous issue cannot be prevented or mitigated with something other than instrumentation.

7. What is a proof-examination interval?
Proof testing is a requirement of safety instrumented systems to ensure that everything is working and performing equally expected. Testing must include the verification of the entire system, logic solver, sensors, and terminal elements. The interval is the menstruation of time that the testing occurs. The testing frequency varies for each SIS and is dependent on the technology, arrangement architecture, and target SIL level. The proof-test interval is an important component of the probability of failure on need adding for the system.

8. What is a Procedure Hazard Analysis (PHA) and who
conducts this?
A PHA is an OSHA directive that identifies condom bug and risks within a procedure, develops corrective actions to reply to safety issues, and preplans alternative emergency actions if condom systems fail. The PHA must be conducted by a diverse squad that has specific expertise in the process existence analyzed. At that place are many consulting and applied science firms that too provide PHA services. PHA methodologies tin can include a What-If Analysis, Hazard and Operability Study (HAZOP), Failure Manner and Effects Analysis (FEMA), and a Mistake Tree Assay.

9. What voting configurations are required for each SIL level?
Obtaining a desired SIL level is dependent on a multitude of factors. The type of technology employed, the number of organization components, the probability of failure on demand (PFD) numbers for each component, the system architecture (eastward.chiliad., redundancy, voting), and the proof testing intervals all play a pregnant role in the conclusion of a SIL level. There is not a standard answer for what voting configurations are required for each SIL level. The voting compages must be analyzed in the context of all the factors noted in a higher place.

10. Will a SIL rated system require increased maintenance?
SIL solutions are certainly not always the nigh toll-effective solutions for decreasing process risk. Many times, implementing a SIL solution will require increased equipment, which inevitably volition require increased maintenance. Additionally, it is likely that the college the SIL level, the more than frequent the proof testing interval will be, which may ultimately increase the amount of system maintenance that is required. This is why the standards recommend a SIL based solution only when process risk cannot be reduced past other methods, as determined by LOPA.

11. Can a F&G system be a SIF or Sis?
A Fire and Gas (F&G) system that automatically initiates process actions to prevent or mitigate a hazardous event and subsequently takes the process to a safe state can exist considered a Rubber Instrumented Function / Safety Instrumented System.

However, information technology is absolutely critical in a F&G system to ensure optimal sensor placement. If there is wrong placement of the gas / flame detectors and chancy gases and flames are not adequately detected, then the SIF / Sis will non be effective.

Correct sensor placement is more of import than deciding whether a F&G SIF / SIS should be SIL two or SIL 3.

12. What is SIL 4?
SIL 4 is the highest level of gamble reduction that can exist obtained through a Condom Instrumented System. However, in the process industry this is non a realistic level and currently at that place are few, if any, products / systems that back up this prophylactic integrity level.

SIL 4 systems are typically then circuitous and plush that they are not economically beneficial to implement. Additionally, if a process includes so much risk that a SIL 4 system is required to bring it to a safe country, and so fundamentally at that place is a problem in the process design which needs to be addressed by a procedure change or other non-instrumented method.

xiii. Tin an individual product exist SIL rated?
No. Private products are only suitable for utilise in a SIL environment. A SIL level applies to a Safety Instrumented Function / Condom Instrumented Organization.

fourteen. What type of communication buses or protocols are applicative for SIL ii or SIL 3 systems?
The type of advice protocol that is suitable for a SIL ii or SIL 3 system is really dependent on the type of platform that is beingness used. Options include, just are not express to: four-20 mA output indicate, ControlNet (Allen Bradley), DeviceNet Safety (Allen Bradley), SafetyNet (MTL), and PROFIsafe. Currently, the ISA SP84 commission is working on developing guidelines for a safe jitney, to make certain that the foundations comply with IEC 61508, and IEC 61511 standards. The offset devices with a safety omnibus should be available by 2008. The Fieldbus Foundation is actively involved in the commission and working on establishing Foundation Fieldbus Safety Instrumented Systems (FFSIS) projection to piece of work with vendors and end users to develop safety bus specifications.

15. For Full general Monitors, how can I access the PFD and MTBF data for the products?
The General Monitors SIL certificates take the PFD, SFF, and SIL numbers that correspond to each product. MTBF data tin can be provided by request.

16. Can a manufacturer state their products are "SIL X certified" rather than "suitable for use in a SIL Ten organisation"?
Individual products are only suitable for use in a SIL environment. A SIL level applies to a Safety Instrumented Part / Condom Instrumented Arrangement.

Product certificates are issued either by the manufacturer (self-certification), or other contained agency to show that the advisable procedure is followed, calculations have been performed, and analysis has been completed on the private products to indicate that they are compatible for apply within a system of a given SIL level.

Full IEC 61508 certification tin apply to a manufacturer�s processes. Full certification implies that a manufacturer�s product development procedure meets the standards ready along in the appropriate parts of sections 2 � 3 of IEC 61508 (including hardware / organization and software). Receiving full certification from an accredited notifying body gives the terminate user confidence that the manufacturer�south engineering procedure has been reviewed and its production�s electrical content, firmware and logic take been assessed and conform to the guidelines gear up along in the standard.

There are very few nationally accredited bodies that can effect nationally accredited certifications. Other consulting firms issue certificates that indicate that the product and / or procedure has been reviewed by an independent 3rd party.

17. Tin can a manufacturer state their products meet all parts of the requirements of IEC 61508 parts 1 to 7?
IEC 61508 consists of the following parts, under the general title Functional Safety of electrical/electronic/programmable electronic safety-related systems:

Function 1: General requirements
Function ii: Requirements for electric / electronic/programmable electronic
safety-related systems
Part three: Software requirements
Part 4: Definitions and abbreviations
Part 5: Examples of methods for the determination of safety integrity levels
Part half dozen: Guidelines on the application of parts 2 and 3
Part vii: Overview of techniques and measures

To be in compliance with the standard, it is necessary to conform to Parts 1 � 3. Parts 4 � 8 are informative just and can be useful in agreement and applying the standard, but do not have requirements for conformance.

Manufacturers of products by and large meet Section 2 requirements to determine through a FMEDA analysis that their products are suitable for use inside a given SIL level.

Companies choosing to certify their engineering processes and receive full IEC 61508 certification volition also comply with Section 3 every bit it relates to software development.

eighteen. What does SIL X suitable hateful, is this a valid argument as per the standard IEC 61508 or tin any other wording exist used? SIL stands for Safety Integrity Level. A SIL is a measure of safety system operation, or probability of failure on need (PFD) for a SIF or Sister. There are four detached integrity levels associated with SIL. The college the SIL level, the lower the probability of failure on demand for the prophylactic system and the better the system performance. It is of import to also annotation that every bit the SIL level increases, typically the cost and complexity of the system also increment.

A SIL level applies to an entire organization if information technology reduces the risk in the amount corresponding to an appropriate SIL level. Private products or components practice not accept SIL ratings. SIL levels are used when implementing a SIF that must reduce an existing intolerable process risk level to a tolerable chance range.

To be compliant with the standards. Information technology is upward to the user to ensure that procedures have been followed properly, the proof testing is conducted correctly, and suitable documentation of the design, process, and procedures exists. The equipment or organization must be used in the manner in which it was intended in club to successfully obtain the desired gamble reduction level. Just buying SIL 2 or SIL 3 suitable components does not ensure a SIL two or SIL iii system.