EBV Fireproofing

If possible, do not install an EBV and its actuator in any fire zone. If a non-fail-safe EBV is installed in a fire-hazardous area, then fireproof all components within the fire zone. These components include the actuator, the wiring, the control devices and the valve (if it has an elastomer seat or liner).

It is normal practice to mount control devices, such as limit switches, solenoid valves and air filters, in a fireproofed enclosure.

Any non-fireproofed component of a non-fail-safe EBV is a weak link during a fire and will cause the installation to malfunction.

Consider fireproofing fail-safe EBVs in a fire-hazardous area if the EBV is to be operator initiated, rather than fire initiated.

Historically, fire blankets and rigid enclosures providing protection have required conscientious, ongoing maintenance. A maintenance-free, epoxy-type, intumescent, spray coating, called K-MASS, has been developed and tested successfully. The ½-inch thick coating is sprayed and bonded to actuators and over control enclosures. During a fire, it expands to provide protection for the equipment for over 30 minutes.

Recently, molded covers made of K-MASS were fire tested successfully on a quarter-turn valve with an elastomer liner. The results, detailed in the Southwest Research Institute Report Number 6-302, showed that soft or non-metal seated valves can be successfully used as EBVs in hydrocarbon services within fire areas. The covers are installed in the field after the flange bolts are tightened. For inspection or adjustment of the valve, the covers can be removed easily with special tools.

For HF Mitigation, the operating plants chose a monel-plug valve with a TFE liner for their EBV’s. This valve would not pass the through-valve leakage requirements in Edition 3 of API Standard 607, Fire Test for Soft-Seated Quarter-Turn Valves. The historical, industry-wide performance of these plug valves in this service, however, was excellent compared to the specially designed gate valves. For any EBVs located in fire-hazardous areas, consider adding special, molded, fireproofing covers made form K-MASS over the valve body.

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