Process Units
Process Unit Valve Reference

Valves for the Fluid Catalytic Cracking Unit (FCC)

Converts heavy gasoil into gasoline and olefins over a fluidised catalyst at high temperature. Erosive catalyst circulation and cyclic thermal-mechanical duty make this the refinery's most severe valve service.

Oil & Gas RefiningPetrochemical

What are the critical valves in a Fluid Catalytic Cracking Unit?

Wet gas compressor anti-surge (Control Valves) — Prevents surge on the erosive, high-molecular-weight wet-gas stream. Regenerator/reactor relief (Safety & Relief Valves) — Fire-case and blocked-outlet overpressure protection on the highest-temperature vessels in the unit. Main fractionator bottoms (Gate Valves) — Hot, solids-bearing slurry service demanding abrasion-tolerant trim.

Critical Valve Points

Wet gas compressor anti-surge

Control Valves

Prevents surge on the erosive, high-molecular-weight wet-gas stream.

Regenerator/reactor relief

Safety & Relief Valves

Fire-case and blocked-outlet overpressure protection on the highest-temperature vessels in the unit.

Main fractionator bottoms

Gate Valves

Hot, solids-bearing slurry service demanding abrasion-tolerant trim.

Unit-Level Valve Strategy

  • Catalyst-slide and standpipe valves see continuous erosive duty - hard-faced or ceramic-lined trim is standard practice, not an upgrade option
  • Main air blower and wet-gas compressor isolation follows severe-service rotating-equipment practice with anti-surge protection
  • Regenerator and reactor overpressure protection is a fire-case-driven relief study, not a routine PSV sizing exercise

Equipment in this Unit

Fluids in this Unit

Governing Standards

API 617ASME Section VIIIAPI 520API 521API 6D

Related process units

Reviewed by Process Engineering, Vajra Industrial SolutionsDiscipline: Valve Service SpecificationLast reviewed: 20 June 2026

Connected Engineering

Sourcing valves for a Fluid Catalytic Cracking Unit?

Send your unit valve list — we supply the full set (Control Valves, Safety & Relief Valves, Gate Valves) with certification matched to API 617, in one PO.

Engineering references