Always try to reduce all possible ‘blind spots’ where product may become trapped, never use reducing nipples or T-pieces on the inlet or outlet of a pump.

To ensure components are easy to access and maintain, consider using some of the following tips.

General plumbing tips for the spray operator

Fittings

• It is preferable to have fittings that are easy to remove for installation, maintenance and repairs, such as Banjo®, GEOLine or ARAG® fittings.

• Where two fittings need to be screwed into each other, use thick (pink) plumber’s tape and thread paste to make sealing, adjustment and removal easier. Do not use silastic-type products or stag. Silastic is hard do anything with if there is a leak, and fittings that have been put together with stag are very hard to get apart.

Hose clamps

• Use good-quality stainless steel hose clamps with a solid band. It is a good idea to spray lubricant onto the hose clamp before trying to adjust them, new or old. It is easier to tighten a hose clamp if you apply lubricant, unscrew the clamp for a bit and then tighten. If you try to tighten the hose clamp without doing these steps, you may not get the clamp as tight as you need.

Hoses

• Make the sprayer plumbing simple as possible, always try to reduce the amount of hose used, and reduce or eliminate blind spots.

• The TeeJet® Catalogue 51- M (https://www.teejet.com/-/media/dam/agricultural/usa/sales-material/catalog/cat51a_metric.pdf) includes useful information on pressure drops through various hose diameters related to the length of hose and the flow rate.

• Hose with crossover webbing is good for going around bends due to its flexibility. However, it can expand too much when being pressurised or de-pressurised if the pressure rating is not high enough. The result of the hose expanding may be that it takes a while for the nozzles to come on (because the hose needs to expand) and the nozzles can take a while to shut off (because the hose needs to contract to original size).

• Use hose that is the same size or larger than the fittings on the pump.

• Use a hot-air gun to make removing hose from fittings easier and boiling water to install hose onto fittings. Do not tighten hose clamps before the hose has cooled off.

Components

• To make plumbing easier it is best to make up separate manifolds rather than try to put all spray components into a single manifold.

• Use nipple, fly-nuts-and-tails e.g. GEOline and ARAG® fittings and/or flange fittings e.g. Banjo® Manifold Systems, TeeJet® DirectoValve Flange Fittings. These fittings make it easy to make minor changes to the sprayer when conducting maintenance or repairs to the sprayer’s plumbing.

• Install a pressure gauge outside the windscreen of the sprayer or spray tractor that is connected as close to the nozzles as possible. Leave the other pressure gauge at the front of the sprayer (on the pressure line from the pump) so the operator knows what the pump pressure is and can easily identify pressure changes between the pump exit and the operating nozzles.

• Use filters (suction and pressure) that have a thread on the bottom of the bowl for the installation of a manual ball valve to make flushing easier.