HID 1-2014: Failure of a foot valve actuator on an LPG road tanker to operate on demand at low temperatures created by a loss of containment (link)
A recent HSE investigation has found that piston actuators fitted to safety critical foot valves on LPG road tankers may not operate on demand at low temperatures created by a loss of containment.
Subsequent low temperature tests on similar valves showed that two types of piston actuators also failed to move a valve to the closed position.
Operators of vehicles which fall within the scope of the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2009, CDG, and the operators of COMAH establishments who store or transport substances that have the potential to create low temperatures during a loss of containment incident are advised to take the steps detailed in this notice to ensure that this risk is addressed.
Source: HSE