Effective and competent silo servicing routines are essential for any safety system. The MPA (Mineral Products Association) has recently published (2022) a detailed document explaining all of the nessasary checks required to maintain your silo safety system. These checks include the pressure relief valve (PRV), pressure sensor, filter, inlet control valve, panel and the ultimate high-level sensor: all essential for maintaining a healthy and reliable silo safety system.
Every employer has a legal responsibility under The Provision and Use of Work Equipment Regulations 1998 (PUWER REGS) to ensure that the equipment used in the workplace is suitable for use and for the purpose and conditions in which it is to be used: i.e maintained in a safe condition for use so that people’s health and safety is not at risk. It must be inspected to ensure that it is and continues to be safe for use and the inspection should be carried out by a competent person. This person must have the necessary skills, knowledge and experience to perform this task and a record kept until the next inspection.
Pressure relief valves (PRVs) are the last line of defence against over-pressure. With effective protection and servicing, blocks like the example above can be avoided.
On initial inspection, this PRV appeared fine, but a closer look under the lid reveals the opposite. This problem would indicate the silo safety system has failed.
After physical testing, this PRV and associated pressure sensor failed to operate at the correct setpoints. Previously this unit was serviced with only a visual inspection.
Damaged and neglected filter cartridges if they are completely blocked, will have the potential to cause a serious silo over-pressure. Damaged or split filter cartridges can cause serious emission issues if they burst.