Vent and blowdown silencers are designed to reduce the extreme noise levels produced during the rapid venting of high-pressure steam, gas, or air to atmosphere. This noise typically results from events such as:
Steam safety relief valve discharge
Blowdown of natural gas pipelines during maintenance Boiler startup steam dumps
Depressurization of process lines or vessels
Steam ejector exhaust or pressure safety valve (PSV) release
Such events create instantaneous pressure changes and violent turbulence, resulting in sound pressure levels that often exceed occupational and environmental noise limits.
To address this, vent and blowdown silencers use a reactive-absorptive
acoustic design. The reactive section reduces velocity and shock through diffuser technology, while the absorptive section dissipates broadband and high- frequency energy through acoustic media—providing balanced attenuation across all octave bands.
Reactive-Absorptive Design
Controls both low-frequency shock noise and high-frequency turbulent mixing.
High-Pressure Capability
Suitable for steam, natural gas, air, nitrogen, and other process gases.
Custom-Engineered for Each Application
Designed based on flow rate, pressure, temperature, gas type, and required insertion loss.
Advantages:
Non-Overloading, Direct-Drive
Fan Impeller Overhung on Motor Shaft Type CC Navy Standard
Built per MIL-F-19004
Sizes:
11 Sizes
300 CFM to 14,000 CFM
Up to 6 in. w.g
Typical Applications:
General Ventilation
Intake/Supply and Discharge/Exhaust Systems A/C Systems
Backward-curved centrifugal fans with high airflow and AMCA-certified performance.
Advantages:
Backward Curve Design Full Line of Accessories
AMCA-Certified for Air and Sound
Non-Overloading Horsepower Characteristics
Sizes:
14 Sizes
12 in. to 40 in. Wheel Diameter
Up to 56,000 CFM and 17 in. SP w.g
Typical Applications:
Supply Air Return Air Exhaust Air
Mechanical Spaces Ventilation
Model AF Fans
Compact, corrosion-resistant cast aluminum blowers ideal for tight marine spaces.
Advantages:
Rugged, Lightweight, Rust-Proof Cast Aluminum Housing
Direct or Belt-Drive Options
Compact Form Factor
Accessories Available
Sizes:
Up to 5,000 CFM
Pressure up to 26 in. SO w.g
Typical Applications:
Hull Venting
Bathroom Exhaust
Spark-Resistant Applications
Storage and Pump Rooms
SC Blowers
Compact, high-volume forward curve blowers for low-noise marine use.
Advantages:
Multivaned Forward Curve Wheel
High Volume, Low Noise
Flange or Base Outlet Mounting
Special Configurations Available
Compact Design
Sizes:
Up to 1,400 CFM
Pressure up to 4 in. SP w.g
Typical Applications:
Where Quiet, Compact Blower is Required
AF Cast Aluminum Pressure Blowers
Volumes to 3,800 CFM Pressures to 20″ w.g
Lightweight aluminum field-rotatable housing
Corrosion- and spark-resistant aluminum wheels
Backward, forward, and radial blade types
Direct and belt drive options
Six basic fan sizes with custom options
Turbo Pressure Blowers
Volumes to 9,200
CFM Pressures to 86″ w.g
Continuously welded, heavy-gauge housing
Direct and belt drive options
Backward-curved and radial blade wheels
Eight basic fan sizes with custom options
RB Pressure Blowers
Volumes to 12,000 CFM
Pressures to 110″ w.g
Radial blade wheel
Twenty-five standardsizes
Continuously welded heavy-duty construction
Direct and belt drive options
Custom configurations available
BCA, BCS – Single Width
Volumes to 100,000 CFM
Pressures to 25″ w.g
AMCA-certified for air and sound performance
Backward curved C airfoil blade designs
Eighteen standard sizes, rotatable housing
Belt or direct drive
QBCA, QBCS – Square Housed
Volumes to 43,000 CFM
Pressures to 17″ w.g
AMCA certified
Compact square housings, four discharge positions
Fourteen basic fan sizes
Backward curved C airfoil blade wheels
PBCA, PBCS – Plug Fans
Volumes to 90,000 CFM
Pressures to 12″ w.g
Belt drive only
Backward curved C airfoil blades
Insulated plug options
Sixteen fan sizes, three plug depths
DBCA, DBCS – Double Width
Volumes to 190,000 CFM
Pressures to 20″ w.g
Sixteen sizes
Rotatable, continuously welded housings
Available in square housing versions (DQBCA, DQBCS)
Industrial Exhausters
Heavy-duty radial blade fans for material handling and air movement.
Volumes to 40,000 CFM
Pressures to 23″ w.g
Radial blade wheel
Belt or direct drive
Reversible and rotatable housings on sizes 7–12
Twelve basic sizes
Designed for severe-duty material handling and air applications
Custom options available
Built for Marine and Industrial Offshore Duty
Available in Direct Drive or Belt Drive Configurations
High-Pressure Options Up to 110″ w.g.
Capacities Up to 190,000 CFM
Optional Explosion-Proof and Spark-Resistant Construction
Continuously Welded, Heavy-Gauge Rotatable Housings
Cast Aluminum, Steel, or Stainless Steel Options
Custom Coatings, Accessories, and Mounting Options Available
Engineered to meet the demands of extreme marine environments, American Fan centrifugal blowers are purpose-built for performance, safety, and longevity. Each fan is designed for optimal airflow performance and minimal energy consumption, while offering corrosion resistance and easy maintenance access. Whether operating in enclosed machinery rooms or exposed offshore decks, these fans are built to last.
⬛ High-Performance Wheel Types (Backward Curve, Forward Curve, Radial Blade)
⬛ AMCA Certified for Sound and Airflow (Where Applicable)
⬛ MIL-Standard Options Available
⬛ Field Rotatable Housings for Flexible Installation
⬛ Designed for Shipboard Noise, Heat, and Vibration Conditions
⬛ Custom Configurations for Pressure, Space, or Noise-Sensitive Zones
At Ochoa Industries, we provide custom design solutions for industrial and marine applications. Our specialties include ventilation, noise control, and explosion-proof air conditioning, focusing on performance and safety.
Copyright © 2025 Ochoa Industries, All rights reserved.
