Vent Silencers

Steam exhausts
Air vents
Process Gases
Relief valves
Safety valves
Bypass valves
Blow down vents
High temp vents

Diffuser Silencers

Atmospheric vents
Control valves
Pressure let down
Steam Vents & Process Vents
Pressure regulators

In-Line Silencers

Control valves
Orifice plates
Gas ejectors
Steam ejectors
Gas compressors
Axial compressors
Centifugal compressors
Roots blowers and
Multi-lobe blowers and exhausters

Surge Tanks

Drinking Water
Raw water
Foul Water

Ancillary Surge Controls & Equipment

Air Compressors
Electrical Controls Control Panels
Level Controls

Flo-Dyne Installation & Commissioning Services

Pipeline Surge Analysis & Reporting

Refurbishment and repair

Surge Vessels
Compressor systems
Control panels

Pulsation Dampeners

Roots Blowers
Multi-Lobe Blowers
Recip compressor
Recip pumps Suction Lines
Discharge Lines

Acoustic Filters

Hydraulic pumps
Refrigerant Compressors
Air Conditioning Compressors

General Information

Quality Registration to

Surge Tanks


Vent Silencers


Pulsation Dampeners


In-line Silencers

Blower Silencers





Unexpected release of steam or gas to atmosphere from a safety relief valve creates noise which is dangerous to plant personnel and is environmentally unacceptable.

The gas or steam released from either low pressure (LP steam vent silencer) or high pressure (HP steam vent silencer) safety relief valve will normally result in very high noise levels, often more than 150 dB(A) at 1 metre, which, as well as being dangerous to personnel, can result in acoustic fatigue in the pipework or equipment that is immediately downstream of the valve.

Flo-Dyne's safety relief valve vent silencer, model type BOS, can be supplied with an inlet diffuser built to pressure vessel standards, that will let down the inlet pressure to atmospheric pressure without restricting the exhaust flow and causing excessive accumulation of pressure at the relief valve.

Whilst care must be taken with the selection of pressure drop across a safety relief valve silencer, a pressure drop can usually be selected in compliance with a local or national standard (such as ASME or BS) that will not cause excessive accumulated pressure at the relief valve and restrict the exhaust flow. With an increased pressure drop across the silencer it may be possible to reduce the diameter of the connected pipework.

Flo-Dyne can advise on a suitable pressure drop for the silencer.

Flo-Dyne will examine each case individually and offer the most economical approach by optimizing silencer design and pressure drop to give a guaranteed solution.

Where there is a risk of blockage of the inlet diffuser Flo-Dyne can provide additional safety protection to prevent the possibilty of the relief system failing.

Silencers may be packed or pack free diffuser only types depending on the duty requirements. Where a packed silencer is needed the packing material will often be chosen from glass fibre, mineral or ceramic fibre as considered appropriate for the operating conditions.

The structural design of the Flo-Dyne Vent Silencer is given the same thorough attention as its acoustic design. The external shell is constructed of seamless pipe in smaller sizes and continuously welded rolled plate in larger diameter silencers. Mounted horizontally or vertically, pads or cradle type supports are available for easy installation.

Contact us now with your requirements.

UK office:
Tel: +44 (0) 1494 770088
Fax: +44 (0) 1494 770099
Email: sales@flo-dyne.net

India office:
Tel: + 91 77 384 97 300
Email: sales-india@flo-dyne.net