Silo Logic

Industrial Materials Handling Specialists

Solutions to Your Material Handling Problems

Silo Over Pressure and Over Filling Safety System 

The powder transfer process

The majority of tankers delivering to sites are non-tipping, belly tankers on-board compressors both pressurise the air in the tanker up to 2 bar and also provide air to fluidise and transport the powder by dense phase pneumatic conveying into the silo. The setting of the various air control valves is the responsibility of the tanker driver and this becomes very critical as each tanker compartment empties of powder. As soon as there is minimal powder in the silo feed pipe, there is in effect, an open connection between the tanker, at 30 psi, and the silo, at atmospheric pressure. In this situation, the air speed in the feed line can suddenly escalate. An experienced tanker driver will try to regulate the airflow as the last of the powder empties from the tanker but, if the driver has not started to reduce the tanker pressure before the end of the powder discharge, then over-pressurisation of the silo can occur within seconds of the feed pipe being empty.

Silo System Components

Control panel IP65, fitted with door interlocked isolator
Pressure relief valve - the pressure relief valve (VCP) will to respond to silo over-pressurisation exceeding 500mm water gauge. When activated the fill pipe shut-off valve will close after 5 seconds
High level alarm with rotation sensor, paddle type, when activated the fill pipe shut-off valve will close after 10 seconds (adjustable), if rotation stops a warning will be displayed on control panel.
Ultimate high level alarm (optional), paddle type, when activated the fill pipe shut-off valve will close immediately.
Over pressurisation gauge, transducer displaying actual silo pressure at the tanker filling point, when 1st set point is activated alarm sounds (300mm/water gauge), when 2nd set point is activated alarm sounds and close the shut off valve after 5 seconds (450mm/water gauge)
Silo filling pipe automatic shut-off valve, butterfly valve (normally closed), option for pinch valve (normally open), option for pinch valve (normally closed)
Filter pressure gauge, indicates the presents of compressed air at the filter (if applicable)
Audible alarm, mounted on control panel
Visual alarm, flashing beacon mounted on control panel
Silo fill pipe connection, mounted on the silo fill pipe with micro switch

We are also able to supply an ATEX Food Compliant Silo Safety System.

Please email us on for a quotation or further information

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21 Beauchamp Rd


Gl20 7TA


Tel: 07754648489