Process Units
Process Unit Valve Reference

Valves for the Crude Distillation Unit (CDU)

The refinery's first unit: crude oil is heated, flashed and fractionated into straight-run cuts. High-temperature, high-throughput service with continuous 3-5 year run lengths between turnarounds - valve reliability here sets the whole refinery's uptime.

Oil & Gas Refining

What are the critical valves in a Crude Distillation Unit?

Furnace inlet/outlet isolation (Gate Valves) — High-temperature crude service ahead of the fired heater; thermal cycling drives the gate-valve selection. Column side-draw control (Control Valves) — Product-cut flow control off each fractionation tray. Overhead reflux and relief (Safety & Relief Valves) — Column overpressure protection sized for loss of overhead condensing.

Critical Valve Points

Furnace inlet/outlet isolation

Gate Valves

High-temperature crude service ahead of the fired heater; thermal cycling drives the gate-valve selection.

Column side-draw control

Control Valves

Product-cut flow control off each fractionation tray.

Overhead reflux and relief

Safety & Relief Valves

Column overpressure protection sized for loss of overhead condensing.

Unit-Level Valve Strategy

  • Column and exchanger-train isolation is planned around the multi-week turnaround, not routine maintenance - valve population per column runs into the hundreds
  • High-temperature crude and hot-oil circuits demand pressure-seal or bolted-bonnet gate valves rated for continuous thermal cycling
  • Desalter and wet-crude sections need corrosion-resistant trim (salt/chloride exposure) distinct from the dry fractionation sections

Equipment in this Unit

Fluids in this Unit

Governing Standards

API 650ASME Section VIIIAPI 520API 521API 600

Related process units

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

Connected Engineering

Standards

Sourcing valves for a Crude Distillation Unit?

Send your unit valve list — we supply the full set (Gate Valves, Control Valves, Safety & Relief Valves) with certification matched to API 650, in one PO.

Engineering references