The next international development in Hydropnuematic System is the use of
precharged pressure vessels with a flexible diaphragm of suitable material acting as a
partition between air and water. The tanks are precharged at factory permanently at
the correct optimum pressure as per client's requirements. This does away with the
use of air compressor and its complicated controls. The other major advantage is
that the entire equipment comprising of pumps, tanks, control panel, piping, valves
and cabling are all factory assembled in a compact and neat manner. No additional
time is wasted at client's site for installation. Only suction is to be connected with
the ground level reservoir and discharged to the distribution system, electric supply
to be connected to incoming of the control panel and the system is ready for immediate
commissioning. The systems supplied by HBD are with ELBI, Italian make
precharged diaphragm tanks which are completely machine made with welding done
by automatic robot's having very high precision and accuracy. These tanks are made
of special grade steel and the steel plates are further given epoxy treatment to
prevent corrosion. The tanks are fitted with alimentary rubber bladders and the water
being pumped stays inside the bladder never coming in contact with the steel
components of the tank. This results in the tanks having a very long life as there is
no chance of corrosion. Because of the high accuracy there is almost zero leakage of
air from the tanks and they need to be topped up with very little amount of air,
maybe once in six to eight months. As the air in the tank never comes in contact
with the water there is no chance of air dissolving in the water and escaping in the

With the conventional system the compressed air is in direct contact with the
water under pressure and thus dissolves in the water. This air escapes in the pipes
causing corrosion due to excess oxidation. By providing the system with precharged
diaphragm tank this disadvantage of the conventional system is eliminated.