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‘Fit and Forget’ Flame Arresters – There Is No Such Thing

Posted On : Thursday 12th September

Flame arresters play a critical role in helping to protect people, property and the environment from damage caused by explosions or the ignition of flammable gases. However, for the equipment to perform effectively, there needs to be a programme of regular inspection and maintenance to ensure the flame arresters function effectively when required. A failure to regularly inspect and maintain the products creates a potential explosion hazard. It is therefore important to ensure that the products are correctly installed and specified for the operating conditions in which they will be used. The products must be kept in good condition, with no evidence of mechanical damage, corrosion or blockages, any or all of which could compromise their performance.

As one of the world’s leading suppliers of flame arresters, Elmac Technologies recommends that all devices be inspected, as a minimum within three months of installation and at least annually thereafter. Following on from the findings of the initial inspection by qualified plant personnel, regular maintenance intervals can be agreed and incorporated into the plant operating guidelines. It is an industry standard that any flame arrester should be in service for a maximum of 12 months before receiving some form of maintenance.

It is vital that flame arresters be inspected regularly as they often provide the last line of defence against a potentially catastrophic incident. Insurance premiums can often be reduced on sites having certified flame arresters that have been correctly installed and maintained. Conversely, if there is an incident, the HSE or insurance provider is likely to seek evidence that these safety-critical devices have been well maintained and inspected regularly.

When inspecting a flame arrester, the key is to check whether the element shows any signs of scorching or burn marks that would indicate a flashback or short time burning incident may have occurred.  If such signs are evident then the flame arrester will need to be replaced immediately as its functionality may be compromised and its Maximum Experimental Safe Gap (MESG) can no longer be guaranteed.  The design of the cells or ‘hole’ size in the element bank relates to the MESG and it is this configuration that allows the gas to flow freely, whilst ensuring the flame is extinguished.

There are two directives that relate specifically to flame arresters: ATEX Directive 2014/34/EU (Equipment Directive), and ATEX Directive 1999/92/EC (Workplace Directive). These require that products, sold for use in potentially explosive atmospheres within Europe since July 2003, must comply with certain standards of performance. In the case of flame arresters, this includes the type-testing of designs to ISO 16852:2016 (the European standard for the design and testing of flame arresters) as well as  the compliance auditing and qualification of the design and manufacturing process to ensure reliability and reproducibility of the products made.

Any flame arresters installed that predate ATEX (before 2003) may well not have been subject to any specific testing. Although ATEX does not demand that these flame arresters be replaced immediately, it must be considered that the original technology used may now be obsolete. In recent years, technology and regulations have seen significant developments and, following a risk assessment, it may well be that the elements within the body of the original flame arrester may be found to have been fabricated from some form of knitted mesh or other material that has now been precluded from use as  a flame arrester element. Since the performance of such flame arresters cannot be guaranteed then replacement may be the only option.

To support customers with the maintenance of this safety-critical equipment, Elmac Technologies now has an approved inspection and maintenance partner who can perform on-site, inspections and issue accurate service reports. In addition, compliance can be further assured by customers having their engineers and technicians trained at Elmac’s state-of-the-art technical centre. This will allow them to gain a real understanding of the key operating principles of flame arresters and the correct method for inspecting, maintaining and installing these safety-critical devices.

If you have any questions regarding the installation, maintenance or replacement of flame arresters, then please contact a member of the Elmac team today.