Instrument Air Quality

Pneumatic instruments require exceptionally clean dry air. Contamination causes valve sticking, instrument malfunction, and control problems. Moisture freezes in cold climates blocking air lines. Receiver stores air meeting instrument specifications after drying and filtration.

Receiver Configuration

Horizontal or vertical pressure vessel with clean air inlet from dryer, outlet to instrument distribution headers, drain for minimal condensate, pressure gauge, safety relief valve. Internal surfaces clean preventing contamination pickup.

Operating Pressure

Typical 100-125 psig from compressor discharge. Design pressure per ASME codes typically 150-175 psig. Downstream regulators reduce to instrument requirements usually 15-40 psig. Stable pressure critical for accurate instrument control.

Air Specifications

Dewpoint -40F or lower preventing moisture condensation. Particulate filtration to 1 micron or better. Oil content under 1 ppm. Meets ISA S7.0.01 quality standards for instrument air. Receiver maintains inlet quality if properly designed.

Material Selection

Carbon steel construction per ASME Section VIII. Internal cleanliness critical - no rust, scale, or contamination. External coating protects atmospheric exposure. Design prevents any air quality degradation in storage.

Storage Capacity

Volume sized for minutes of air consumption reducing compressor cycling. Typical 10-50 gallons per scfm compressor capacity. Larger receivers improve pressure stability and reduce compressor starts extending equipment life.

Pressure Control

Compressor starts at low pressure setpoint. Stops at high setpoint. Differential typically 10-20 psi. Proper control minimizes cycling while maintaining adequate pressure for sensitive instruments.

Applications

Refineries, chemical plants, power stations, pharmaceutical facilities, manufacturing operations, and any process facility using pneumatic instruments requiring ultra-clean air supply.

System Integration

Positioned after dryer and final filtration before distribution. Backup nitrogen supply often provided for critical instruments during air system failures. Proper piping maintains air quality to instruments.

Drain System

Manual or automatic drain removes any condensate though properly dried air contains minimal moisture. Regular inspection verifies air quality. Drain provides safety margin against dryer malfunction.

Surge Protection

Volume absorbs sudden demand increases from valve actuation preventing pressure drop affecting other instruments. Provides momentary supply during compressor loading delay. Critical for stable control system operation.

Performance Benefits

Ensures stable pressure for consistent instrument operation. Reduces compressor cycling extending equipment life. Provides surge capacity during demand peaks. Maintains instrument air quality specifications.

Construction Standards

Design per ASME Section VIII Division 1 with U-stamp. Relief valve sized appropriately. Internal cleanliness specifications. Foundation for vessel weight. Complete documentation with capacity calculations.

ERGIL instrument air receiver vessels provide reliable storage of ultra-clean compressed air ensuring precise pneumatic control system operation in industrial facilities.