Situation

Liquid hammer, also known as ‘water hammer’, is a common hydraulic phenomenon in piping systems where liquids flow. It occurs when a moving liquid is abruptly halted or suddenly changes velocity, generating a pressure surge. This can pose serious risks, such as unexpected movement of the pipeline or damage to the piping system, potentially leading to leaks and hazardous situations for employees. The immense forces within the piping when the pressure wave strikes a valve or a bend can cause severe vibrations and a distinct knocking sound—hence the term ‘liquid hammer’.

Companies are increasingly focusing on mitigating this risk, both from a safety perspective for their employees and to ensure compliance with regulatory and insurance requirements. Liquid hammer is particularly hazardous in long piping systems, such as those used in tank storage facilities. The extensive distances—often hundreds of metres of piping—amplify the impact of pressure waves, exacerbating the consequences of liquid hammer.

​Solution

For every pipeline design or modification of an existing piping system, a thorough risk assessment is essential. KH Engineering possesses the expertise to perform this process with precision. It begins with a well-considered design, following the principle of ‘safety by design’, where the primary objective is to minimise pressure build-up caused by liquid hammer.

An effective measure is the controlled and gradual closure of valves. The slower the closure, the lower the likelihood of liquid hammer and its associated risks. Additionally, installing specialised equipment, such as a surge relief valve, can help regulate pressure surges and mitigate their impact.

KH Engineering supports clients in preventing damage caused by liquid hammer through calculations, design, and detailed risk assessments. In any situation where liquid hammer is a factor, we conduct a standard dynamic pipe stress analysis. This enables us to assess the forces exerted on the piping system due to liquid hammer and implement necessary modifications to the pipeline design and its support structures. In doing so, we ensure a safe and reliable piping system.

Customer benefits

Clients who engage KH Engineering can be confident that their installation operates safely and reliably. By implementing our calculated recommendations, the piping system becomes resistant to liquid hammer, significantly reducing the risk of pipeline damage, production disruptions, leaks, and serious accidents. This not only lowers operational and incidental costs but also contributes to extending the lifetime of assets.