Merry Christmas for 2014

GF Piping Systems would like to wish you a safe and enjoyable Christmas, and New Year. We look forward to a busy 2015 for all. Please note that our blog will be not be monitored during the festive season from COB Tuesday 23 December 2014, until Wednesday January 7, 2014. Please note our offices throughout Australia will be closed at midday Wednesday December 24, 2014, and will reopen on Monday January 5, 2014. If you have any urgent inquiries during this time, please contact Simon Naef on 0418 214...

Water Hammer

Water hammer, or surge pressure, is a term used to describe dynamic surges caused by pressure changes in a piping system. They occur whenever there is a deviation from the steady state, i.e. when the velocity of the fluid is increased or decreased, and may be transient or oscillating. Waves of positive or negative pressure may be generated by any of the following: • opening or closing of a valve • pump start-up or shutdown • change in pump or turbine speed • wave action in a feed tank • entrapped air The pressure waves travel along at speeds limited by the speed of sound in the medium, causing the pipe to expand and contract. The energy carried by the wave is dissipated and the waves are progressively damped. The pressure excess to water hammer must be considered in addition to the hydrostatic load, and this total pressure must be sustainable by the piping system. In the case of oscillatory surge pressures extreme caution is needed as surging at the harmonic frequency of the system could lead to catastrophic damage. The maximum positive or negative addition of pressure due to surging is a function of fluid velocity, bulk modulus of elasticity of the fluid, pipe dimensions and the modulus of elasticity of the pipe...