Vacuum Seal Purpose

Process equipment operating under vacuum requires isolation from atmosphere. Simple liquid seals create barrier using liquid leg height. Seal vessel provides controlled liquid level maintaining pressure differential while allowing solids or liquid passage.

Seal Principle

Liquid column height creates pressure seal. Differential pressure equals liquid height times density. 10 feet water seal provides approximately 5 psi differential. Proper level control maintains seal preventing vacuum loss or overflow.

Vessel Design

Vertical configuration with vacuum equipment connection at top, atmospheric or slight pressure connection below seal, liquid makeup maintaining level, overflow protection, level instrumentation controlling seal height. Design accommodates material flow through seal.

Operating Applications

Vacuum distillation column receivers maintaining separation from atmospheric receivers. Vacuum dryers discharging solids while maintaining vacuum. Degassing equipment with material transfer. Any vacuum process requiring atmospheric isolation.

Material Selection

Carbon steel or stainless steel depending on process fluid. Materials resist liquid chemistry at operating temperature. Design handles external atmospheric pressure on vacuum side.

Level Control

Critical for seal effectiveness. Too high floods vacuum equipment. Too low breaks seal losing vacuum. Level transmitter controls makeup maintaining proper seal height. Alarms protect against seal loss.

Seal Liquid

Water most common for seal liquid. Process fluid used where water contamination unacceptable. Seal liquid selection considers compatibility, density, and vapor pressure. Low vapor pressure prevents vaporization into vacuum.

Vacuum Protection

Maintains stable vacuum preventing atmospheric leakage. Seal accommodates pressure variations from process changes. Relief protection prevents excessive vacuum if downstream pressure drops.

Applications

Vacuum distillation systems, solvent recovery under vacuum, pharmaceutical vacuum drying, polymer degassing, vacuum crystallization, and any low-pressure process requiring atmospheric isolation with material transfer capability.

Capacity Sizing

Volume provides surge capacity for level variations. Sizing accommodates maximum flow rates through seal. Adequate freeboard prevents carryover to vacuum equipment.

Performance Benefits

Maintains reliable vacuum isolation. Enables material transfer without vacuum loss. Simple passive sealing requiring minimal maintenance. Proven technology in vacuum processing.

Construction Standards

Design per ASME Section VIII or atmospheric vessel codes depending on pressure. Materials for vacuum and seal liquid service. Complete documentation with hydraulic calculations.

ERGIL vacuum seal vessels provide reliable isolation maintaining stable vacuum conditions while enabling process material flow in low-pressure applications.