VIRES & SINAER: spraying HIGH GRANULOMETRY products

Applicazione a spruzzo con tecnologia SINAER del "Murantico", prodotto della VIRES con granulometria 0,7.


Spray application, using SINAER technology, of the product "Murantico", manufactured by VIRES, having granulometry 0,7.

AIRLESS: diaphragm VS piston

In these years some manufacturers of airless spray units launched the absurd spot “piston airless is better than diaphragm one”.

Particularly users from Anglo-Saxon countries seem to have absorbed this subliminal leitmotiv: in fact in these countries is quite uncommon to find a diaphragm spray unit, even though they are highly appreciated in continental Europe, former USSR, Arab countries, China, Northern and Southern Africa.

In spite of the evidence, the above mentioned companies convinced millions of users to leave diaphragm airless for piston: in fact diaphragm airless was the real innovation, older users certainly remember it.

Who was not up to develop good diaphragm airless models came back to piston technology and launched a campaign to dissuade users buying diaphragm spray equipment.

We do not need to explain why that campaign is based on false statements: we received a letter from New Zealand, written by a user, demonstrating why diaphragm airless is better than piston.

“I am not really fully conversant with performance curves etc that people speak of, I have put below my observations, maybe some assumptions, of how I have perceived it.

Diaphragm seems to provide a smoother flow of pressure to the tip. The piston seems to fluctuated quite markedly as the piston retracts for a new cycle.

I have tested this with manual gauge, I have assumed they use electronic displays so that the operator cannot see the level of pressure fluctuation.

I have in the past also put a surge suppressor on diaphragm airless, similar in function to the surge suppressor you use.

I have often wondered if the large filter they use on the piston sprayers is as much to act as a surge suppressor as it is to filter.

Also steel braid hoses have always seemed superior to me, they are more durable, smaller etc , I have wondered at the move to fabric hose as a need once more to use the flex of the hose to help smooth out the flow of the piston airless sprayers.

The diaphragm is simple electric motor, no complicated electronics. The up side being reliability, cost effectiveness of repair and it is possible to run off a portable generator, whereas many piston airless because of the electronics cannot run off generator.

Due to the direct nature of the drive of diaphragm unit it appears to me there is less mechanical loss and so give more power.

The electronics in the piston airless are often far more susceptible to voltage transients and can be very expensive to repair.

The suction of the diaphragm people often say is less than that of a piston pump, yet I have never observed this, in fact I have never seem a diaphragm pump of similar size to piston that cannot do at least the same products as a piston.

Diaphragm handles abrasive fluids better than pistons. I have had SINAER machine pumping abrasive paints for years where until they bought the SINAER pump they destroyed their piston sprayer within a matter of weeks with the same product.

The cost of maintenance of diaphragm seems to be far less, with only inlet valve, outlet valve, diaphragm and return valve that can go wrong it is far less that piston, when you consider the electronics, the rods, packers , inlet valve, outlet valve and return valves in a piston. The packers in particular seem to require replacement far more regularly that anything in a diaphragm. In the SINAER machines in over 5 years I have never ever had a diaphragm blow.

Once again, I cannot comment on performance curves but I have never seen a piston machine of similar size outperform a diaphragm machine.

If I was going to list advantages of diaphragm I would say:

· Simple

· Reliable

· Cheap to maintain

· Can pump a larger range of paint coating , especially abrasive, in a day and age of growing use of spray plasters this becomes even more important

· Less mechanical loss of power

The only downside that I can see is that the piston works only when being spraying and stops in between. Some people see the diaphragm machine running all the time and getting hot as wasteful of energy.”

M. McCardle – Oakland, New Zealand