Frequently Asked Questions
What's the big deal about the correct choice of componentry for handling liquid fertilisers?On the West Coast of South Australia where much of the original trial work on calcareous soils was carried out, farmers were weaned on probably the most corrosive and aggressive product available - phosphoric acid. This stuff just loves to eat nylon, brass, bronze and lots more - just look at the nylon tee fitting in the photograph at the bottom of this article! Not only have the threads all but disappeared , but a hole has been blown right through the head of the Tee and the item itself has basically crystalised.
A strict regime of clean water purging of the entire system immediately upon shutdown will help immensely in alleviating chemical attack, however the fact remains that these materials are really not suited for use with liquid fertilisers. Sometimes, the use of some of these materials cannot be avoided because certain items may not be commercially available in the most desirous material - just be sure to clean water purge everything.
Although problems such as I have described have not really surfaced much in W.A. - (due to the fact that it has been predominantly liquid N which has been used), things will change when the new P products come onto the market.
Polypropylene, Polyethylene,316 Stainless Steel, PTFE (Teflon), 'Viton' and EPDM are the materials of choice to be used in conjunction with phosphoric acid based liquid fertilisers.
In regard to storage and transport tanks, both polyethylene and fibreglass tanks are commonly used for these purposes - just check with the manufacturer regarding ph levels that their tanks can take. If you intend using bulkhead fittings in your storage tanks make sure that the gaskets are 'Viton'.
To sum things up, 'it is simply false economy not to use quality componentry and fittings constructed of the appropriate materials'. You must prepare for all contingencies!
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