Pressure Systems

Air receivers

  • Excessive corrosion / wastage to shell (either internal or external) – corrosion noted at the Thorough Examination exceeds manufacturers minimum value, this reduces the structural integrity of the receiver and may result in explosion
  • Pressure gauge inaccurate – when checked against a calibrated gauge at the thorough examination a gauge that is greater than 10% inaccurate should be replaced
  • Pressure relief valve seized – as part of the thorough examination a hydraulic test is carried out to confirm correct operation of the valve against its stated pressure rating
  • Safe Working Pressure not clearly visible – this is quite common to find the original receiver data plate missing or positioned towards a wall so it is not easily accessible, the safe working pressure should be clearly visible
  • Excessive moisture / water in vessel found to be in vessel, over time this can lead to corrosion and wastage of the receiver shell, receivers should be drained regularly, or an auto drain device fitted to prevent liquid build up
  • Vessels not appropriately secured to ground – this can increase vibration in the unit leading to catastrophic structural failure, it is advised that all receivers are secured and those with integral compressors / motors should be fitted with anti-vibration mountings

Coffee Machines

  • No previous thorough examination – often the requirement for coffee boilers to be thoroughly examined is overlooked, the Pressure Systems Safety Regulations (PSSR) require that any pressure system that contains steam is subject to a Written Scheme of Examination (WSE) and examination in accordance with the WSE
  • Pressure relief (safety) valve not lifting as intended, it is common with electrically heated coffee boiler that the safety valve will not release at the design pressure, it is advised that this valve is replaced at each annual service / thorough examination
  • System leaks when under pressure
  • Scale build-up inside shell, in some hard water areas when no water filter is fitted this can lead to uneven heating of the boiler shell and ultimately reduce the efficiency and service life of the unit
  • Feed pump check valves not working allowing pressure from the boiler shell being forced back into the fresh water supply, this reduces overall performance and may not allow pressure to be built up
  • Operators not received adequate training – operators must be given clear instruction and training on the use of coffee boilers; training should include details about safety devices and the dangers of incorrect operation