Question 10 of 16: Rapid Shutdown of Direct-Flow Application Systems

Question 10: Rapid Shutdown of Direct-Flow Application Systems (5 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Because irrigation and drag-hose systems apply manure directly and continuously over a moving path, a delayed shutdown (a hose break, a stuck traveller, or an operator error) can discharge a large volume before anyone notices. Methods used to guarantee a fast shutdown include: (1) an emergency stop accessible at the point of application — a pull-cord or stop button on the traveller/reel or along the hose that an operator or bystander can trigger immediately; (2) automatic pressure-loss shutdown — a pressure switch on the pipeline that stops the pump the instant pressure drops (as it would with a hose rupture or disconnection), rather than relying on someone noticing; (3) flow-metering with high/low-flow alarms tied to an automatic pump shutdown, which catches both a burst hose (high flow / low back-pressure) and a blockage; (4) remote/telemetry shutoff — a two-way radio or SCADA link letting an operator stop the pump from the application site without having to run back to the pump house; (5) continuous operator attendance — never leaving a running irrigation or drag-hose system unsupervised, so a human is always positioned to react immediately; and (6) redundant/dual shutoff — pairing an automatic system with a manual backup valve so a single control failure does not leave the system unable to be stopped.