Industry: Sulphur Recovery Unit (SRU)

Reliable Overpressure Protection for API 526 Duty

The Besa 290 API safety valve is a spring-loaded pressure relief valve designed to protect pressurised equipment against overpressure in steam, gas and liquid services. It is built in accordance with API 526 and uses an adjusting ring to tune opening and reseat behaviour, which is important where stable lift, repeatable blowdown and controlled closing are required across changing process conditions.

For typical plant duties, the Besa 290 is supplied in flanged patterns with high-flow, full-nozzle construction and a defined performance basis aligned to API sizing practice (API RP 520 basis is referenced in the 290 technical bulletin flow-rate notes). The published operating characteristics for the 290 series include effective discharge coefficients (Kd) for gas/vapour and liquid service and standard overpressure and blowdown expectations used during sizing and selection.

For technicians, engineers and production managers, this means:

• Fewer nuisance lifts — the adjusting ring allows set-up of stable popping and closing behaviour for consistent relief performance.
• More predictable capacity sizing — published Kd values support repeatable engineering calculations for gas/vapour and liquid duty.
• Clear protection margins — defined overpressure basis (gas/vapour vs liquid) supports compliance with typical relief design assumptions.
• Controlled return to service — defined blowdown expectations help avoid extended loss of product or unstable reseating after a lift event.
• Simpler plant standardisation — one API-pattern valve family covers steam, gases and liquids, reducing spares variety across units.
• Improved maintainability planning — optional accessories such as test gag and limit switch support functional checks and lift indication where required.
• Material fit for duty — availability of carbon steel and stainless steel constructions supports common refinery, chemical and utility services.