Irrigation Management on the Northern Adelaide Plains

Primary Industries and Resources SA is funding an irrigation management program jointly with the Department of Water, Land and Biodiversity Conservation.  On the Northern Adelaide Plains, growers at Virginia will monitor their water-use efficiency and help build sustainable practices in the industry.  For more details click on the link below and scroll to page 5 of the Open Gate Magazine.  Open Gate Magazine 

Pump Maintenance

Denis Sparrow, Senior Irrigation Officer, ICMS, PIRSA, Loxton

The efficiency of pump units relates directly to dollars. Either dollars into your pocket or out of it. The correct selection, operation and maintenance of pump units is essential if maximum efficiency and operational life is to be achieved. Pump units not operated on their most efficient points suffer from extra mechanical damage through additional stress being applied and in some cases cavitation damage to impellers and pump parts. The cost per kilolitre of water pumped is increased and correct coverage or application rates from sprinklers may not be achieved resulting in crop loss. The efficiency of pump units can be maintained and in some cases increased by employing modern overhaul methods, the use of mechanical seals and internal glazing.

Why perform maintenance?

Maintenance of mechanical and electrical plant is essential if equipment is to remain in a safe and reliable condition and perform the duty it was designed to do and in a cost effective manner.

We maintain equipment, to ensure:

• Reliability
• Efficiency
• Extend the asset’s service life

Maintenance levels vary depending on the complexity of equipment and the consequence of failure. We must ensure our pumps and motors are maintained in a safe and reliable condition. The level of maintenance and expenditure can be evaluated by considering the cost of failure.

• Evaluate the risk to personal safety and environment damage
• Crop loss
• Cost of emergency arrangements
• Cost of emergency repairs
• Total loss of asset

What type of maintenance is applicable for a block pump?

Maintenance can be performed by having procedures based on:

Reactive Maintenance

• Maintenance is performed only when it has failed and you are required to act immediately.
• This form of maintenance can be supported by spare parts or in some cases a spare pump so that down time is kept to a minimum.
• Reactive maintenance is not a good method.

Preventative Maintenance

• This form of maintenance requires you to act just prior to failure.
• Deciding on what has to be performed and when is it a major problem.

Predictive Maintenance

• By recording selected readings, noting operational conditions you can try to predict when the unit may fail and of course act prior to this point being reached.
• Predictive maintenance is the best method.

There are other preventative maintenance programs such as Continuous Diagnostic Maintenance which takes constant readings and notes any significant change in the readings. Machine history is also a good tool to predict the life of a pump. It is based upon "like" operation in that it relies upon the history of the previous unit relating to the present unit. Since the taking of readings and observations form a vital part of most maintenance programs what should be looked for?

• Heat – in bearings and glands
• Pressure – pump discharge pressure
• Noise – cavitation, bearings
• Flow – a drop off in flow
• Leakage – glands – piping oil or grease
• Power consumption
• Vibration – an increase could indicate problems

Regardless of type of maintenance program practiced problems will still be experienced. The aim of a maintenance program should be to reduce failure and operational expenditure while still maintaining an efficient unit.

Monthly Preventative Maintenance

Procedure

• Ensure safety of plant and equipment before performing any work
• Record all meter readings. Calculate efficiency
• Check all valves, glands and supports
• Test run unit, check for correct running, noise, heat, vibration
• Adjust gland if required
• Check oil levels if applicable
• Check sump drain pump if applicable
• Clean inside and outside of station
• Check condition of electrical components for hot spots

IMPORTANT – if electrical work is to be performed ensure it is carried out by licensed persons

• Act on any findings

The Irrigated Crop Management Service provides an irrigation management consultancy service. This service assists irrigators to interpret soils, plantings and irrigation systems information. To enquire about this service, call (08) 85959100 or email Sparrow.Denis@saugov.sa.gov.au.

_______________________