These proposed changes to IEC standards for hazardous gas detection expected to take effect in 2020 will impact process manufacturers.
By Jon D. Miller, technical compliance manager, Det-Tronics
Editor's Note: This article is adapted from a white paper, "Gas safety standards are changing in 2020: Will your plant be in compliance?" Download the free, full white paper with additional information about what the changes mean for high-hazard process owners; other relevant codes and standards in transition that will impact selection and installation of gas detection equipment; and benefits of integrating gas detection with fire and smoke detection as a risk mitigation strategy.
Combustible and toxic gas detection is one of the first lines of defense in plant safety, and hazardous process operators understand its critical role in risk mitigation. Soon, however, existing equipment and practices for gas detection may no longer suffice. Significant changes to standards are coming soon — and the best way to verify compliance will be to select, specify and install an integrated fire and gas safety system that will meet the expected 2020 standards.
IEC Updating Combustible Gas Safety Standards
Activity aimed at modernizing and unifying applicable codes and standards has been notable in the area of gas safety systems. One combustible gas related IEC (International Electrotechnical Commission) standard recently released is IEC 60079-29-1:2016, “Explosive atmospheres — Part 29-1: Gas detectors — Performance requirements of detectors for flammable gases.”
The latest edition of this standard specifies general requirements for the construction, testing and performance of fixed gas detectors intended for use in explosive atmospheres, such as those found in petrochemical and hydrocarbon processing facilities. The update adds significant new criteria in four areas, as follows.
1. Ingress protection requires functionality validation.
The ingress protection rating has taken into account only the enclosure protecting the electronics, not the operation of the sensors inside the enclosure. As products become compliant to this new standard, a disclaimer must be placed within the instruction manual stating that the ingress protection rating does not imply that the equipment will detect gas during and after exposure to such conditions. Otherwise, validation testing should be done by an agency or certifier that can verify the manufacturer’s claim.
This change will require plant owners and product specifiers to pay particular attention to manufacturers’ ingress protection for gas detectors intended for outdoor use. By choosing detectors with the “60079-29-1” label marking, plant managers can verify the detectors are rated for the claimed performance.
Not included in the revised combustible gas detection standard are new test requirements that have been gas-performance standard. These requirements, which will allow detector manufacturers to verify product performance and provide the relevant information to a product certification agency, might be incorporated into the next edition of the combustible gas standard.
2. Expanded electromagnetic compatibility testing.
The IEC 60079-29-1: 2007 standard requires evaluating detectors for radiated immunity, as well as power supply interruptions, voltage transients and step changes.
In addition to these tests, the IEC 60079-29-1:2016 standard will require testing for electrostatic discharge, magnetic fields, burst, surge and conducted radio-frequency interference. These changes will align the standard more closely with European electromagnetic compatibility (EMC) requirements. Once detectors meeting the IEC 60079-29-1:2016 requirements are purchased, plant managers must consider any special product installation requirements meant to achieve robust EMC device protection.
3. Software function verification.
Although software requirements are included in the IEC 60079-29-1:2006 version of the standard, the IEC 60079-29-1: 2016 standard includes a test clause for software function verification, which is meant to improve the reliability of software functions. This testing will require validation against the requirements, and manufacturers will need to provide evidence of full compliance.
One way that manufacturers can demonstrate compliance is by using approval agencies such as FM, CSA, UL, DEKRA EXAM GmbH or Sira. Detection system controllers that have received agency approval for software functionality will be labeled as meeting the IEC-60079-29-1 standard.
4. “Upper limits” system testing.
The word “system” here refers to gas detectors in conjunction with their controller. The new standard clarifies requirements for equipment using digital communications during normal gas detection operation. The standard calls for detection systems to be tested under maximum communication transaction rates and activity levels.
In addition, the largest and most complex system configuration must be used for testing. These requirements are meant to test necessary safety actions under conditions that simulate the limits of normal gas detection operations.
Det-Tronics, based in Minneapolis, is a participating Encompass? Product Partner in the Rockwell Automation PartnerNetwork? program. Det-Tronics makes the Eagle Quantum Premier? (EQP) flame and gas safety controller with DLR outputs, a SIL 2 capable, fault-tolerant, addressable system that integrates with a process control system.
The Journal From Rockwell Automation and Our PartnerNetwork? is published by Putman Media, Inc.