[graham banks]

I keep hearing about internal body wear in these pumps being caused by poorly mixed powder chemicals and corrosion.
In my experience there are few cleaning chemicals aggressive enough to cause this.  It is cavitation that is the problem caused by dirty solution filter, kinked solution feed pipe or a feed too small in diameter...starving the pump.
Cavitation is microscopic air bubbles (you cant see them) caused by not having a free flow to the pump, pressurisation of liquid splitting out some oxygen from the water and it is as aggressive as sand. If you strip down an HP Pump suffering from this you will see the internals scoured away....The pump is a right off. New piston,seals,poppet valves etc. will not help.
Graham

[M.Acorn]

Would I be right in assuming that this could affect all pumps ?
Have had problems with kinked feed hose in the past,and may go some way to explaining my run of pump problems last year

[graham banks]

All pumps need a good feed however the flojet/shurflo  diaphram pumps have the ability of suckig water into themselves so do not usually have this type of problem.
The piston type pump can not draw water in and must have a positive head of water feeding them with clear easy to flow through piping.
Hope this helps
Graham

[JandS]

If you get cavitation you know about it straight away
it makes a right tacket.

John

[Mike Halliday]

the only time i see kinked pipe is on the machines that have a clam design were you can tilt open the tanks to reveal the pump and vacs, the manufacturers need to put a bit of slack on the solution lines to allow the machine to open or where they have skimped on the fitting so bend the pipe instead of fitting an elbow to the pump.

most portable will have a positive flow of water to the pump as the water tanks tends to be above the pump.

[mark shannon]

Graham showed me the effects of cavitation on my old pump stripped down , will be making sure the filters clean every time I dig the Recoil out in future.

mark

[stuart_clark]

I was talking to the main agent for Pumptec at the cleaning show and just verified what you said about cavitation and microscopic air bubbles causing wear to the internal part of the pump! he said you can easily overcome this by fitting a second supply tube to the pump! and there is a second port onb the pump head for this

[graham banks]

Hello Stuart
The guy you spoke to about Pumptec pumps at the cleaning show was me.
Small world isn,t it ?
Graham

[Ian Gourlay]

Very interesting but if machine is designed right  how do you get a feed to small in diameter

[stuart_clark]

Good heavens Graham , are you 63 Mate ? i wouldnt have put you a day over 40 !!!!!

P S you can pay me later graham Lol

[graham banks]

Hi Ian,    It happens, restrictions not always just hose diameter but reduced orrifices through fittings etc. Twin feed is a good route to take where possible