Reduce noise at your plant with pneumatic mufflers

Compressed air systems and air blowing are usually the sources of loud, sudden noise in factory or plant settings. Air blowing causes a sudden noise when the compressed air system releases the air. The loud noise is generated by the air turbulence created when the air expands freely. Controlling turbulence reduces noise. There are two sources of noise when compressed air is used: first, noise from the air blasts used for cleaning, cooling, transport, and sorting; second, and generally more aggressive sounding, the noise from the venting valves used in fluid power. The solutions required to control turbulence and reduce noise from these two sources are very different. Today we’re presenting a solution you can use to reduce noise from venting valves: pneumatic mufflers.

Pneumatic valves: the 1st source of harmful noise

Some of the most harmful noise that occurs when using a compressed air system is created by the exhaust of compressed air from pneumatic valves. Did you know that a valve with ½ in. ports used to control a pneumatic cylinder at 3 cycles per second can produce a noise level equivalent to 92 dB of continuous sound? It’s been scientifically proven that continuous, repetitive exposure to noise greater than 90 dB causes permanent partial or complete deafness. Fortunately, noise can be controlled and, in factory or plant settings, you can reduce noise in order to safeguard the hearing health of workers.

What the law says about exposure to noise 

In a work environment, sound levels do not add up, they combine: if two noise sources emit 80 dB, the measured exposure level will be 83 dB. The employer must provide hearing protection when the noise level exceeds the values in the table below (on the A scale of a standard sound level meter with the data indicated).

OSHA 29CFR 1910.95 (A) Occupational Noise Exposure.

Pneumatic mufflers: the solution to reduce noise

Pneumatic mufflers or exhaust mufflers are an ideal way to quietly evacuate compressed air from air valves, pneumatic motors, and pneumatic impact tools. They suppress the noise of air exhaust from pneumatic valves and help preserve hearing health. They also prevent unprotected valve ports from being contaminated by dirt and outside impurities.

Pneumatic mufflers and maintenance 

All mufflers should be periodically inspected to check for any contaminants inside. If you find contaminants inside the mufflers, they must be cleaned. This can be a good indicator that you need to filter the air supplied to your equipment.

How to choose a pneumatic muffler

Before selecting a pneumatic muffler, make sure you’re familiar with these three points:

1. Airflow

• The muffler’s maximum airflow (SCFM) must be equal to or greater than the flow of the device on which it is installed. This avoids excessive air restriction, a key to maintaining satisfactory performance. Make sure that the pneumatic muffler’s airflow capacity is at least equal to the flow rate specified by the manufacturer of the pneumatic tool, valve, or other equipment. If these data are not available, choose a muffler with a thread that is at least equal in diameter to the port of the tool or equipment.

2. The material used to make the body and filter

• In a highly corrosive environment, choose a muffler made of stainless steel or plastic.

3. The type of equipment used and the available space

• Mufflers come in different sizes. To determine the right muffler size, consider the pressure of the air blast and the type of equipment. Some mufflers are designed for higher working pressures or to prevent excess air blasts, like those for air exhaust or for relief valves. In general, these mufflers are more "massive” and provide enhanced noise reduction. In contrast, more compact mufflers that do not meet the same performance criteria are perfectly suited to smaller spaces, especially at the outlet of a valve.

The different types of pneumatic mufflers or filters

You can buy different models of exhaust mufflers. Below is a selection of Topring pneumatic mufflers that reduce noise, safeguard hearing health, and improve the quality of the working environment at a plant or factory.

	Air Exhaust Mufflers Vacuum chamber muffles noise and reduces velocity while dispersing the residual air through the muffler ports. Maximum working pressure: 125 PSI > See our selection
	Relief Valve Mufflers If contaminants obstruct the muffler, the safety valve automatically opens to immediately release the compressed air. Eliminates excessive noise by dividing the airflow and turning it back on itself. Maximum working pressure: 175 PSI > See our selection
	Molded Acetal Plastic Mufflers / Filters No maintenance required when used under normal working conditions. Resistant to corrosive environments. Can be installed so that compressed air flows in the desired direction (away from user). Maximum working pressure: 116 PSI (acetal plastic element) / 150 PSI (polyethylene element) > See our selection
	Sintered Bronze or Stainless Steel Mufflers / Filters Compact – ideal for use in limited spaces Tough metal structure Available in stainless steel for corrosive environments Can be cleaned with conventional solvents Maximum working pressure: 116 PSI > See our bronze selection > See our stainless steel selection
	Compact Breather Vent Filters Useful when space is limited and/or to prevent contamination Can be inserted into the exhaust ports of pneumatic equipment without affecting its dimension Maximum working pressure: 125–174 PSI (based on thread size) > See our selection
	Speed Control Mufflers Adapts to the exhaust ports of pneumatic valves to safely regulate airflow and keep it at an acceptable sound level Maximum working pressure: 145 PSI > See our selection
	High Flow Pneumatic Mufflers Quick, cost-efficient way to reduce noise Protects the inside surfaces of pneumatic valves from contamination by outside impurities entering through valve ports Maximum working pressure: 125 PSI (zinc plated steel body) / 300 PSI (aluminum body) > See our selection

For more information on fluid power, on how to reduce noise generated by compressed air exhaust, or on pneumatic mufflers, contact a Technical Advisor at 1-800-263-8677 or by email at solutions@topring.ca.