O.M.T.

TARTARINI

Noise due to pressure regulation

Stream margin

Stream core withturbulence bubbles

Shock waves noise

Stream core with sonicor supersonic velocity

Vel

oci

ty o

n t

he

pip

ing

axi

s

Inle

t v

elo

city

High turbulencemixing area

Turb

ule

nt

gas

str

eam

(dis

trib

ute

d in

th

e se

ctio

n)

Ou

tlet

vel

oci

ty

Mixing area with spectrumof irregular velocity for magnitude and direction

O.M.T.

TARTARINI

Velocity m/s

No

ise

dB

(A)

70

75

80

85

90

95

100

10 20 30 40 50 60 70 80 90 100

Noise calculated withIEC method forsilenced regulators

Noise measured1 m downstream of thesilenced regulator

Noise produced by theexpansion joint

67

O.M.T.

TARTARINI

Primary or active actions• noise reduction at its source, i.e. in the regulator

• use of suitable silencers placed in the piping downstream of the regulator

Secondary or passive actions• soundproofing of the piping downstream of the

regulator or the whole installation

• protection with cabinet

NOISE REDUCTION

O.M.T.

TARTARINI

V>200 m/

V< 80 m/

V=120 m/

30

25

35

20

15

10

5

70 75 80 85 90 95 100 105 110 115 120

Noise of the regulator without silencer dB(A)

No

ise

red

uct

ion

dB

(A)

TYPE SR BUILT-IN SILENCE

O.M.T.

TARTARINI

30

25

35

20

15

10

570 75 80 85 90 95 100 105 110 115 120

Noise of the regulator without silencer dB(A)

No

ise

red

uct

ion

dB

(A)SILENCER TYPE SRS

40SR silencer

Multi-stage section

Multi-pathsection

O.M.T.

TARTARINI

STP 10

STP 20

30

25

35

20

15

10

570 75 80 85 90 95 100 105 110

SILENCER TYPE STP

40

Noise of the regulator with silencer dB(A)

No

ise

re

du

ctio

n d

B(A

)Deadening material

Porouschannels

O.M.T.

TARTARINI

40

50

60

70

80

90

100

110

0 5000 10000 15000 20000 25000 30000

Standard

SR

SRS

SRS+STP10

SRS+STP20

No

ise

dB

(A)

Flow rate Stm /h3

FL/80 RegulatorNoise foreseen with different silencing systems

Pe = 30 bar - Pa = 6 bar

O.M.T.

TARTARINI

STL-Type line silencersmeasurements executed close to the pipin

"T" couplingwithout silencer

"T" couplingwith silencer

100

104

105104

100

9795Reactionsection

Dissipationsection

98

O.M.T.

TARTARINI

dB(A)110

115

100

95

90

85

80

75

70

65

6000

200064

4000128

6000193

8000256

10000321

12000386

Without silencers

One multi-path section on theclosing member (Cg: -3%)

Two multi-stage sections inthe downstream flange(Cg: -8%)

Combined: one multi-pathsection on the closing memberand two multi-stage sections inthe downstream flange (Cg: -10%)Combined two multi-pathsection and two multi-stagesections (Cg: -15%)

Stm /hm/s

3

O.M.T.

TARTARINI

FL/100-SR Pressure RegulatorMeasurements executed in anechoic chamber

RegulatorFL/100-SR

60

70

80

90

100

110

5000 10000 15000 20000 25000 30000 35000

Flow rate Stm /h3

Working conditionsN

ois

e d

B(A

)

FL/100

FL/100-SRInlet pressure = 35 barOutlet pressure= 8 barMax. flow rate = 30000 Stm /hFL/100 Noise = 105 dB(A)FL/100-SR Noise= 85 dB(A)Noise reduction= 20 dB(A)

3

O.M.T.

TARTARINI

Regulating line installed in the openFL/80-SRS Pressure Regulator

Working conditionsInlet pressure = 24 barOutlet pressure = 6 bar

Noise measured underworking conditions

1 m from the downstream piping76 dB(A)

Noise foreseen with anon silenced regulator

99 dB(A)Noise reduction

23 dB(A)

Spectrum of sound emissions in octave ban

6 125 250 500 1K 2K 4K 8K 16

29 34 39 45 60 74 72 69 65

Hz

dB

Flow rate = 12000 Stm /h3

FL/150 Pressure Regulator with built-in SR silencerSTP downstream silencer

Working conditionsInlet pressure = 45 barOutlet pressure = 21 bar

Spectrum of sound emissions in octave band

Regulating line installed in the open

500 1K 2K 4K 8K 16K

46 55 59 59 58 55

Hz

dB

O.M.T.

TARTARINI

RegulatorFL/150-SR Silencer

STP20/500

A

1.5 m

1 m.

Noise foreseen witha non silenced regulator

100 dB(A)

Noise reduction 35 dB(A)

Noise measured in "A"position and underworking conditions

64.5 dB(A)Flow rate = 25000 Stm /h3

O.M.T.

TARTARINI

RegulatorMFL/50-SR

SilencerSTL/50

Silencing of a regulating station by fitting SR silencers onregulators and STL silencers on lines

Working conditions

Inlet pressure = 48 barOutlet pressure = 4 barFlow rate = 7000 Stm /h3

Noise measured in the middle of the regulatingstation under working conditionsBefore the modification 108 dB(A)After the modification 75 dB(A)

63 125 250 500 1K 2K 4K 8K 16K

30 33 38 50 56 68 74 72 65

Spectrum of sound emissions in octave bandValues measured after the modification

Noise total reduction 33 dB(A)

Reduction due to SR 21 dB(A)

Reduction due to STL 12 dB(A)

Hz

dB

O.M.T.

TARTARINI

STL/200

FL/150-SRRegulators

Installation modificationFitting of SR-silenced regulators and STL silencers

Inlet pressure 40 bar1st stage outlet pressure 5 bar2nd stage outlet pressure 3 barFlow rate 6000 Stm /hNoise inside the cabinet 73 dB(A)

3

Noise measured in the middle of the station

Before the modification 105 dB(A)

After the modification 73 dB(A)

Noise total reduction 32 dB(A)Reduction due to SR 19 dB(A)

Reduction due to STL 13 dB(A)

STL/200

STL/200

FL/150-SRRegulators

FL/150-SRRegulators

STL/200

STL/200

FL/150-SRRegulators

FL/150-SRRegulators

O.M.T.

TARTARINI

• Reaction-dissipation type silencersMulti-passage or flow break down type

Multi-stage or pressure jumping

• Dissipation or absorption type

NOISE REDUCTION IN THE REGULATOR

• Various reaction or dissipation type silencers

Silencers inserted in downstream pipe