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Industrial Acoustic Insulation, reduce noise and protect people | Paroc Article
Stone wool insulation material with a pair of headphones, illustrating its use in acoustic insulation.

Industrial Acoustic Insulation: noise reduction

Written By Paroc•Date Published 2024-09-01

Noise Is More Than an Inconvenience

In power plants, process facilities, and heavy industry, noise isn’t just annoying, it’s dangerous. Chronic exposure to high noise levels can lead to irreversible hearing loss, stress-related illnesses, and even cardiovascular disease1. According to the World Health Organization, noise-induced hearing impairment is the most widespread irreversible occupational hazard globally, affecting over 120 million people2 .

Unchecked noise can also impact productivity and safety in that:

  • Workers may struggle to concentrate and communicate.
  • Accident risks can rise when alarms and warnings go unheard.
  • Absenteeism and early retirement may impact operational efficiency, create logistical issues and increase operational costs.

Reducing noise is about helping people with the hope of increasing productivity. PAROC has tested and certified acoustic insulation systems  for a variety of industrial applications. That includes both hot systems with PAROC Stonewool; and a combined acoustic solution with FOAMGLAS cellular glass material, also part of Owens Corning, with their cold and cryogenic systems too. 

Furthermore, we have even tested solutions that include our CUI Spacer system, for when extra mitigation against corrosion is specified.

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Why Noise Reduction in Industrial Pipelines Matters

Industrial pipelines often transport air, steam, or liquids at high pressure and speed, generating continuous noise levels that can exceed 100 dB(A)—far above the threshold of 85 dB(A), where ear protection is required. At these levels communication becomes difficult, alarms go unnoticed and safety incidents become more likely.

Effective acoustic insulation is essential, not just for compliance, but for creating an efficient workplace. Noise doesn’t just harm hearing, but it can impact every aspect of well-being performance, for example, physical health, mental strain, reduced focus and safety risks.

Noise reduction in industrial pipelines, image

Standards That Matter

ISO 15665 (Acoustic insulation for pipes, valves and flanges) defines acoustic classes (A, B, C, and Shell Class D) and minimum insertion loss requirements for pipe insulation systems. Compliance ensures effective noise control and helps meet health and safety regulations. 

  • Class A: Basic noise reduction
  • Class B: Medium performance
  • Class C: High performance
  • Shell Class D: Maximum performance for demanding environments

In addition, numbers 1,2 or 3 are added to indicate applicable pipe size, for example in Class C:

C1 applies at pipe diameters less than 300mm

C2 applies at pipe diameters between 300mm and 650mm

C3 applies at pipe diameters from 650mm to 1000mm


Furthermore, ISO 15665 details recommended material properties for the porous layer in an acoustic system, in order to convert acoustic and vibratory energy. It specifically names mineral fibre (stone wool) with a density of 80 kg/m³ to 120 kg/m³ as a suitable material.



Acoustic insulation for pipes, valves and flanges

PAROC Industrial Acoustic Insulation Solutions

PAROC has tested and certified acoustic insulation systems for industrial pipelines, valves, and flanges. The solutions we can detail:

  • Cover all ISO 15665 classes (A-D) and recommended porous layer properties.
  • Combine acoustic performance with thermal insulation and fire safety.
  • Offer easy installation without additional support structures, which otherwise in some cases will increase noise.
  • Can be easily calculated for final sound reduction benefit. In the below example, the reduction is from 95 dB(A) to 77 dB(A).


Calculated dBA

Totals

Hz

125

250

500

1000

2000

4000

8000


Uninsulated

75

81

86

90

91

81

79

95

ISO 15665 Class C3 insertion loss

1

9

17

26

34

38

42


Insulated

74

72

69

64

57

43

37

77

Source: Internal calculation based on applied insertion loss

It is important to note that a 10 dB(A) reduction is perceived to be heard as half of the pre-insulated sound level.

PAROC acoustic solution

In the table below, you can see the data for our tested and certified acoustic insulation systems for industrial pipelines and the corresponding ISO 15665 class.

Acoustic 15665 Test Results

Class

Range of nominal pipe diameter

Layer material

Density / weight

Thickness

B2

300 mm < 650 mm

PAROC® Pro Section WR 120

120 kg/m³

50 mm

Metal sheet cladding


0.7 mm

C1

< 300 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

3 x 2.5 mm

Metal sheet cladding


0.7 mm

< 300 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

PAROC® CUI Spacers

15 mm

Metal sheet cladding

0.7 mm

C2

300 mm < 650 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

2 x 2,5 mm

Metal sheet cladding

1.0 mm

300 mm < 650 mm

PAROC® Pro Section WR 100

100 kg/m³

60 mm

PAROC® CUI Spacers

15 mm

Vinyl mass layers

5 kg/m²

2.5 mm

Metal sheet cladding

1.0 mm

C3

650 mm - 1000 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

Vinyl mass layers


2 x 2.5 mm

Metal sheet cladding

1.0 mm

D2

300 mm < 650 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

2 x 2.5 mm

PAROC® Pro Section WR 100

50 mm

Vinyl mass layers

5 kg/m²

2 x 2.5 mm

Metal sheet cladding

1.0 mm

300 mm < 650 mm

PAROC® Pro Section WR 100

100 kg/m³

60 mm

PAROC® CUI Spacers

15 mm

Vinyl mass layers

2 x 2.5 mm

Metal sheet cladding

1.0 mm

D3

650 mm - 1000 mm

PAROC® Pro Section WR 100

100 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

2 x 2.5 mm

PAROC® Pro Section WR 100

50 mm

Vinyl mass layers

5 kg/m²

3 x 2.5 mm

Metal sheet cladding

1.0 mm

650 mm - 1000 mm

PAROC® Pro Section WR 140

140 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

2 x 2.5 mm

PAROC® Pro Section WR 140

140 kg/m³

50 mm

Vinyl mass layers

5 kg/m²

4 x 2.5 mm

Metal sheet cladding

1.0 mm


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