Biosecure over-/underpressure protection type ST-DS - make biogas plant operation as safe as possible
It can either be controlled mechanically through a biogas storage membrane or using weight-operated immersion cups. The ST-DS housing is made of stainless steel; the immersion cups and the steering linkage are plastic. We use water as sealing liquid to which antifreeze is added at low outside temperatures. As an option, an insulating jacket or an electric heating rod can be installed to prevent the water from freezing when no antifreeze is added. The functioning inside the housing can be checked through the built-in sight glass.
The ST-DS has been designed as a safety component in the sense of the 2006/42/EC Machinery Directive.
However, the safety we intent to achieve when operating a biogas plant can only be accomplished in practice if all necessary measures are taken. It falls within the operator's duty of care to support these measures and to check their execution.
Product overview biosecure over-/underpressure protection ST-DS
Structure of the biosecure over-/underpressure protection ST-DS
The overpressure protection can optionally be controlled pneumatically or pneumatically/mechanically by means of a plastic tension strap.
The mechanical control mechanism comprises a star-shaped plastic tension strap (6) connected to the ST-DS (3) above the gas storage membrane (2) of the digester (5).
Components of the biosecure over-/underpressure protection ST-DS
Control of the biosecure over-/underpressure protection ST-DS
a. Mechanical control using the plastic tension strap
b. Pneumatic control by high pressure in the digester
Extension for ST-DS
Insulating jacket (insulation)
The back wall of the digester and the gas inlet opening transfer heat to the sealing liquid in the overpressure protection. Depending on the substrate temperature inside the digester, the insulating jacket is able to prevent freezing of the sealing liquid down to an outside temperature of -20°C.
Electric heating rod
Technical data biosecure over-/underpressure protection ST-DS
Pickup pressure of the ST-DS
overpressure (283 g equivalent to 1 mbar) in overpressure valve pneumatic 3.8 mbar at 1075 g weight of the bell
underpressure (300 g equivalent to 1 mbar) pneumatic -1.0 mbar at 300 g weight of bell II in the underpressure valve
Excess filling: mechanically via plastic tension strap
Gas volume flow: 200 m³ per hour
Outlet pipe flange: DIN 150 (stainless steel)
Extension: with PEHD pipe, OD 160, max. length 3 m
Without heat insulation on the outside and during winter operation: water with addition of antifreeze agent
Option: electric heating rod with freeze guard: water
Sight glass: soda lime glass similar to DIN 8902 with wiper made of PTFE
Connection at digester wall: DN 200 (standard), DN 150 (option)
Dimensions: Length 860 mm x Width 750 mm x Height 1370 mm
Downloads for biosecure over-/underpressure protection ST-DS
|Datenblatt Über- und Unterdrucksicherung ST-DS_DE|
|Datenblatt Über- und Unterdrucksicherung ST-DS_EN|
|101 002 02 BRO ST DS DE KD.pdf|
|101 019 01 BRO ST DS FR KD.pdf|