Identifying any requirement for surge suppression or alleviation on a system at an early stage is highly beneficial, allowing a range of options to be formulated and presented to the client, thus ensuring fundamental design decisions can be made on the basis of cost, timescales and practicality.
These options may range from a fundamental change of the system in order to design out identified issues through to installing surge suppression or alleviation equipment in conjunction with revisions to the proposed operating control philosophy in order to ensure the integrity of the system at all times.
Whilst being involved on a project at an early stage is the ideal scenario, Hydraulic Analysis Limited is regularly invited by clients to analyse existing systems where surge pressures or system performance issues have been identified to propose remedial measures in order to solve these problems. This often involves working closely with our onsite testing department and utilising the troubleshooting expertise of our experienced engineers.
A brief summary of some of the most regularly employed surge suppression / alleviation methods is detailed below, however it should be noted that Hydraulic Analysis Limited treat every system independently and as such, identify the most applicable solutions for the client’s consideration.
- changes to system design at an early stage
- use of air valves / vacuum breakers in conjunction with analysis air inflow / outflow characteristics
- evaluation of valve stroke times / characteristics modifications to operating control philosophies and pumping regimes
- surge vessels and accumulators (as well as potential backflow restrictors etc)
- bursting discs
- NRV studies to determine whether fast acting / standard / inline NRVs are required to prevent NRV slam
- pressure relief valves
- variable speed drives
- HIPPS (high integrity pressure protection systems) & OPPS (over pressure protection systems)
- dump valves and recycle valves
- controlled start-up regimes especially with the potential for drained sections of pipework or vapour pockets in the system
It is imperative that any proposed surge suppression or alleviation requirements are analysed thoroughly as it has been shown that inaccurate sizing, whether it be for example a surge vessel, relief valve or a stroke time, can further exacerbate existing issues or create new surge or operational problems.
Should surge suppression / alleviation measures be required, then they must be cost effective, practical and compatible with system operating philosophies and regimes, which is a fundamental issue that Hydraulic Analysis Limited addresses with every project we undertake.