SAFETY RELIEF VALVE VENT SILENCERS

Additional Details

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 equiment that is immediately downstream of the valve.

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