Silencers by Parker Legris for compressed air systems

Silencers for Compressed Air Systems from Parker Legris

Silencers from Parker Legris reduce noise levels in compressed air systems while simultaneously maintaining high exhaust flow rates. For industrial applications, precise characteristic data regarding design, material used, and connection types are crucial. These devices combine low pressure drop and reliable particle filtration, thereby protecting control and drive components and ensuring that workplaces comply with legal noise limits.

Materials and Designs

Parker Legris offers silencers in various materials such as polyethylene, brass, and sintered bronze. Polyethylene silencers are characterized by corrosion resistance and low cost; they are suitable for dry, clean compressed air applications with moderate pressure and ambient temperatures. Brass versions offer higher mechanical strength and more temperature-resistant connections in industrial environments. Sintered bronze inserts are used when, in addition to sound damping, additional filtration of particles or oil mist is required. Sintered bronze filters the finest particles and stabilizes flow over a wide operating range. Regarding designs, a distinction is made between compact inline models, cylindrical variants, and combined throttle valve silencers (throttle valve silencers). Inline models are suitable for space-saving arrangements directly on valves or cylinders, cylindrical models at exhaust ports of control blocks, and throttle valve silencers allow the combination of sound damping and fine regulation of exhaust air speed without additional components.

Connections, Threads, and Seals

Parker Legris silencers are available with common connection standards: metric internal and external threads, BSP variants, and quick-connect interfaces for modular systems. Typical sizes range from M5 over 1/8", 1/4" to 1/2" and larger. The connection technology influences installation behavior and tightness: brass and stainless steel threads use PTFE or O-ring seals, while polyethylene models often rely on form-fitting union nuts and sealing washers. During installation, the selection of the seal must be matched to the maximum pressure and ambient temperature; nitrile (Buna-N) is standard for clean compressed air systems, fluorinated elastomers (FKM) for higher temperatures or chemical exposure.

Performance and Pressure Drop

Important for design is the maximum volumetric flow rate (l/min or m3/h), the permissible operating pressure, and the resulting pressure drop. Parker Legris silencers are designed to reduce sound pressure by several decibels without pushing the pressure drop beyond critical limits. When selecting: Check the flow characteristic curve of the silencer at your system pressure setting; especially with throttle valve silencers, a tight throttling significantly changes the acoustic efficiency and pressure drop.

Areas of Application and Suitability

Typical applications include pneumatic cylinders, directional control valves and valve islands, compressor vents, and pneumatic tools in manufacturing. In paint shops, assembly islands, and test benches, silencers reduce workplace noise, improve metrology conditions, and prevent backflow effects. For cleanroom or sensitive production areas, sintered bronze versions are preferably used as they retain particles and thus reduce contamination risks.

Installation, Maintenance, and Replacement Intervals

A correctly mounted silencer sits tightly at the exhaust point and has sufficient accessibility for maintenance or replacement. In modular designs with quick connectors, a plug-in system reduces downtime. Maintenance work includes visual inspection, removal, and cleaning or replacement of the filter element. Polyethylene models can be rinsed with mild cleaning agents; sintered bronze elements can be cleaned in ultrasonic baths or replaced if the flow significantly decreases. Document the installation location and reasons for failure in the maintenance plan to systematically optimize replacement intervals.

Concrete Practical Examples

Practical Example 1 — Pneumatic Cylinder in Assembly Island: In an assembly line with 120 cycles/min, compact Parker Legris inline silencers made of brass are installed at the cylinder exhausts. Installation: Screw the silencer directly onto the M5 exhaust bore, replace the O-ring, and set the system to 6 bar. Result: Sound pressure reduction at the workplace by 8 dB with unchanged cylinder cycle; no change in performance. Practical Example 2 — Test Bench with Oil-Contaminated Exhaust Air: In a test bench for hydraulic components, oil-containing exhaust air is present. Solution: Use of a sintered bronze silencer with an additional oil separator. Installation: 1/4" BSP connection at the vent port; regular inspection every 3 months. Result: Fine particle and oil retention, stable measurement conditions, extended lifespan of downstream sensor technology. Practical Example 3 — Throttle Valve Silencer for Regulating Piston Ejection: In a packaging machine, the ejection speed of the piston was too high, causing both noise and material stress. Process: Replacement of the standard silencer with a throttle valve silencer. Adjustment: Gradually reduce the throttle opening until the desired ramp time is achieved. Result: Noise level decreases, piston impact energy reduced, cycle time remains within target range.

Selection Criteria and Checklist

When selecting a Parker Legris silencer, the following points should be checked: * Material (polyethylene, brass, sintered bronze) suitable for the application * Connection size and thread type * Maximum volumetric flow rate and permissible operating pressure * Necessity of filtration or oil separation * Maintenance accessibility and replacement frequency For technical specifications, data sheets, and exact flow curves, please refer to the Parker Legris product pages and technical information, as well as our category page. Additional information on application cases and technology can be found here: Technik and here: Anwendungsbeispiele.

Standards, Safety, and Compliance

Select silencers that comply with relevant standards for noise protection and pressure equipment. Observe local occupational safety regulations regarding maximum exposure to sound. In case of explosion hazards or flammable media, standard silencers are not suitable; consult manufacturer data for suitability in Ex zones.

Dimensioning in Project Operation

For integration into existing pneumatic systems, coordinated calculation of volumetric flow, pressure drop, and actuation times is necessary. Determine the sum of exhaust air volumes per valve/port and select silencers with sufficient free cross-sectional area. For multiple vents in close proximity, a combined solution with central exhaust throttles and individual silencers at critical points is recommended to reduce the acoustic load in a distributed manner.

Procurement and Variants

Parker Legris offers standardized series as well as special solutions with various connection and filter options. Custom designs may include material changes, specific threads, or adapted sintered structures. For technical documents or suitable article numbers, our product catalogs and sales team can assist.

FAQs

1. How do I choose between polyethylene and sintered bronze? Polyethylene is suitable for clean, cost-sensitive applications without high temperature or oil exposure. Choose sintered bronze if particle filtration, oil separation, or higher temperature resistance are required. 2. Does a silencer affect the cycle time of my pneumatic cylinder? A silencer can slightly increase the pressure drop; with normally dimensioned devices, the effect is negligible. However, with tight throttle settings or incorrectly dimensioned silencers, the cycle time can increase. Use flow characteristic curves for verification. 3. How often do silencers need to be maintained or replaced? Maintenance intervals depend on operating conditions. In clean systems, a visual inspection every 6–12 months is sufficient. For oil-containing or dust-laden exhaust air, inspections and cleanings are advisable quarterly; sintered bronze elements are replaced when visibly contaminated or when flow is noticeably reduced.