Graphics-based waterhammer program

The Hytran program uses extensive graphics to show the pressures associated with waterhammer and has been developed specifically for analysing the pipe systems used in the water and wastewater industry.

Transient pressures (commonly called waterhammer) occur in any pipeline when the velocity of flow changes. Valve closure and pump trip are common causes but other circumstances such as start-up tests under non-standard conditions may generate unexpected transient conditions.

Waterhammer pressures can sometimes cause serious damage to pipeline equipment such as non-return valves and pumps, or even cause pipeline rupture. As part of a risk analysis on water and wastewater pipelines a waterhammer investigation should always be carried out.

An essential element of programs used for this type of analysis is the real-time graphical representation of the pressure waves. The program must include visualisation of the pressure transients travelling in the pipeline over time, and also time-dependent transients at fixed points such as pump stations.

Graphical presentation of results provides not just a summary of the calculation; it assists in a greater understanding of the phenomenon. It's easy to appreciate the effect of a reflected wave from a sea wall because the wave pattern can be directly observed; a graphical presentation of pipeline transients provides a similar understanding of waterhammer.

The Hytran program uses a simple drag-and-drop technique to generate a flowsheet representation of the pipe system and a wide range of equipment items can be simulated. These include multiple pumps, check valves, discharge tanks, control valves and air chambers. The program also includes an extensive reporting system.