Collection Function

Relief valve discharge contains high-pressure high-temperature fluids requiring safe handling. Direct atmospheric venting creates hazards from toxic gases, flammable vapors, scalding steam, or hot liquids. Blowdown vessels capture discharges, separate phases, cool liquids, and route vapors to safe disposal preventing ground-level exposure and equipment damage.

Vessel Design

Vertical or horizontal knockout drum with inlet sized for maximum relief flow. Vapor space separates gas from liquid. Quench water injection cools hot discharges. Vapor outlet routes gas to flare, scrubber, or vent. Liquid drain connects to closed systems. ERGIL sizes vessels based on relief valve capacity, discharge conditions, and required cooling.

Design Conditions

Inlet section rated for relief valve set pressure typically 150-1500 psig. Design accommodates thermal shock from hot discharges. Adequate volume prevents overpressurization during relief events. Materials handle diverse relief streams including hydrocarbons, steam, acids, and toxic compounds.

Material Selection

Carbon steel construction suitable for most applications. Stainless steel for corrosive discharges containing H₂S, chlorides, or acids. Internal spray nozzles for quench water distribution. Design per ASME Section VIII with materials meeting relief system requirements.

Applications

Process vessel relief valve collection, steam boiler safety valve discharge, compressor relief handling, reactor overpressure protection, and storage tank emergency venting. Serves refineries, chemical plants, power generation, and any facility requiring safe relief valve discharge management.

Quench Systems

Water injection cools hot vapor or liquid discharges reducing temperature to safe levels. Spray nozzles ensure intimate contact. Quench water supply from cooling water or fire water systems. Flow activated automatically during relief events.

Control Features

Level switches manage liquid inventory preventing overflow. Temperature monitoring verifies adequate cooling. Pressure transmitters detect relief events. Integration with facility alarm systems alerts operators. Automated quench activation during discharge.

Vapor Handling

Non-condensable vapors route to flare system for thermal destruction. Condensable vapors cool and separate in vessel. Steam condenses with quench water reducing vent loads. Proper vapor routing prevents atmospheric release of hazardous materials.

Performance Benefits

Protects personnel from hot high-pressure discharges. Prevents equipment damage from relief valve exhaust. Enables environmental compliance through controlled disposal. Reduces noise from direct atmospheric venting. Simple proven technology for safe relief valve operation.

Construction Standards

Design per API 521 pressure relief systems and ASME Section VIII. Relief sizing accounts for combined valve discharges. Materials suitable for relief streams. Complete documentation with hydraulic calculations supporting safe discharge handling.

ERGIL safety valve blowdown vessels deliver dependable discharge collection ensuring safe relief valve operation and protecting personnel and environment.