The Health and Safety Executive (HSE) has issued a safety alert addressed to users of tank containers and road tankers, haulage companies and those servicing pressure/vacuum relief valves on them.
Road tankers and tank containers which transport flammable, corrosive and toxic substances usually have a valve fitted to prevent damage caused to the tank from changes in pressure.
In April 2020 there was an incident where an HGV driver noticed vapour leaking from his tanker when transporting nitric acid. An investigation found that the pressure relief valve on the tanker had an unauthorised modification made to it by a third party which meant it couldn’t operate safely.
Actions required
As a result, the HSE want all users, owners and operators of such equipment to inspect and have verified the performance of these valves on their tank containers and road tanker barrels.
Users should visually inspect the pressure/vacuum relief valves fitted to tank containers and road tankers. The inspection should establish if there have been any unauthorised modifications made to the valve, particularly items added to the valve to allow for easier dismantling.
In particular:
Where valves have both a pressure and vacuum relief function, then both the over-pressure and under-pressure safety functions should be verified during the pressure test.
Anyone working on relief valves should be competent to do so, and valves should:
If a modification is necessary, the valve manufacturer or similar competent person should be consulted.
For more information, see the:
