With relatively new rules in place regarding the use of sprayers, Alex Heath finds out exactly what needs to be done to get a sprayer through its MOT.
As spring approaches and a flurry of spraying activity begins, now is the perfect time to start pre season maintenance and MOT-prep for your sprayer.
We caught up with Les Boughey, of Central Crop Sprayers in Shropshire, who was busy getting a 2009 Bateman RB26 ready for its annual test.
CHASSIS AND DRIVE TRAIN
COMPRISING a 30-point checklist, every aspect of the sprayer has to be functioning correctly if it is to pass an MOT. This starts underneath the tinwork on a self-propelled, where the spraying apparatus is married to the chassis.
Easily checked, the chassis should be structurally sound, with no cracks in the steel.
Each element of sprayer will generally be welded or bolted, so check nuts and bolts have not rattled free. Likewise, on a trailed machine the chassis should be free of defects, with attention paid to the drawbar.
Pto shafts on selfpropelled and trailed machines should be examined, free of defects and have guards fitted.
On self-propelled machines, the hydrostatic drive is not tested. However, checking for leaks from the wheel motors is always advisable, mitigating the risk of failure on a busy main road and crop contamination.
On our Bateman example, focus should be given to the front axles, where the park brake is located, as these can be more temperamental.
VALVES AND FILTERS
WHILE filters are an item which require frequent checking, thorough washing of the machine after nutrient application will help prevent them from becoming clogged with debris, as was the case with the example RB26, which has two filters.
Other makes may have more, including individual nozzle filters.
Controlling the spray pressure is a major part of the MOT, and in general good practice, for accurate pesticide application.
Responsible for this is the ‘Ramsey’ valve, setting the pressure through a diaphragm. This should always be checked at the start of the season for perishing of the rubber components, which wear whether being used or not.
Mr Boughey takes a pragmatic approach, saying with limited spraying days, small pre-emptive maintenance and replacing mparts such as the Ramsey valve diaphragm could stop frustrating downtime when the pressure is on.
THE spray pump is the heart of the machine and should always be monitored. The example machine has two reservoirs holding oil.
These may not always be level, but at least one should have oil in it. If there is an absence of oil, or the oil appears grey, work should stop immediately and repairs made.
This is typically a failure of the diaphragm, resulting in the oil mixing with water and chemical, thus emulsifying.
A job that can be done on-farm, replacing the diaphragm on a six-cylinder pump costs about £250.
The advice if spraying over 2,000 hectares per year is to service the pump annually.
On smaller units where it is not being worked as hard, every time it is due an MOT a pump service should be done.
AT the business end of the sprayer, it is imperative the booms are in good condition.
Cracks and bends must be ironed out to pass the MOT, but especially on the outer sections.
Weigh up the cost of fixing and repairing them or buying replacements. On our example RB26, replacing the outer breakback wings would cost about £90 per side.
Booms must be running level across their full width, with just a 100mm drop tolerated between the centre and end of the booms on a 24-metre machine.
Fixing this can be relatively straight forward. Re-bushing hinge points is one option, the other is replacing the anti-yaw mechanism (pictured) which may be worn.
Replacement mechanisms cost about £100, with the example Bateman having four of them in total.
TANKS are a common place for leaks to occur, as seals go and pipes wriggle free.
Frequent checking and timely repairs will keep the unit tight. Checking the lid and rim, along with the seal to keep everything inside the tank is also important. Checking the tank is securely fastened to the chassis is also vital.
The sight gauge should have a clear scale on it and there is now a requirement for all the taps to be clearly labelled on the induction hopper, as well as the filling control panel. The can wash should also be functional.
THE pressure gauge should also read true.
For the MOT, a trusted gauge will be used to determine the pressure the sprayer is running at. If the existing gauge is more than 10 per cent out, it will need replacing.
Before the MOT, the sprayer needs running up to five-bar of pressure, or sufficiently high enough that it is outside of its normal working zone. This will identify any pipes or joints that mneed replacing.
Any pipes that have excessive rubbing on them, frequently found around the pivot points of the booms, should also be replaced.
Finally, a jug test will determine how accurate the spray system is, and the pressure tested to threebar on each nozzle. The spray pattern of the nozzles is also examined, so ensure all nozzles are in good condition and applying product at an even rate.
Looking ahead to end of season storage, anti-freeze should be pumped throughout the pipe work of the machine, while the pressure gauge should be removed and stored indoors, limiting frost damage.
THE National Sprayer Testing Scheme was introduced in 2002, but came to prominence in 2016 as a result of the Sustainable Use Directive requiring all pesticide application equipment to be tested on a regular basis.
While the legislation requires a minimum of testing once every three years, some insurance companies require more frequent inspection, so it is worth clarifying with them how often is acceptable.