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Installation, use and maintenance
12.3 HYDRAULIC CONNECTIONS
ATTENTION
The use of accessories that are unsuitable and were not provided with the
system is strictly prohibited. Piusi S.p.A. accepts no responsibility for dam-
age to persons, property or the environment caused by failure to comply
with this requirement.
Always follow the below-listed instructions:
- Use pipes and joints suitable for operation in vacuum conditions.
- Use pipes and accessories suitable for treated fluid. Unsuitable materials
can result in serious damage to the pump; they can also cause pollution.
- Do not use conical threaded connectors that could cause damage to the
threaded connector on the pump filter if tightened excessively
- Use wide-radius bends so that pressure losses are reduced to minimum
levels.
- Check that suction pipe is perfectly clean and free from scales.
- Install a FOOT VALVE equipped with FILTER at suction pipe end. Place
the foot valve on tank bottom. Foot valve and pipe must have the SAME
DIAMETER.
- Before starting installation, make sure that no packing material has been
left in the pipes.
SUCTION LINE
The diameter of the “Ds” suction line must be selected according to the sta-
tion model and the position of the station with respect to the tank. With ref-
erence to the “Hp” and “Ls” values indicated at point 12.1, the following MINI-
MUM DIAMETERS of the suction pipe must always be ensured.
MAXIMUM
LENGTH OF
THE SUCTION
PIPES
The maximum length of the tubing, the diameter of the tubing, the difference
in height, are parameters that are tightly linked to creating suction conditions.
The latter must not be such as to create back pressure greater than 0.6 bar. It
follows as a consequence that, after respecting the minimum diameter of the
tubing specified in the “Recommendations and Warnings” below, the length
of the tubing decreases as the difference in height that the diesel fuel must
overcome increases and vice versa: in fact, the back pressure progressively in-
creases by 0.08 bar for every meter increase in the static height of the pump
with respect to the level of the diesel fuel in the tank.
RECOMMEN-
DATIONS AND
WARNINGS
- The suction pipe must resist a pressure of at least 10 bar and must be of a
diameter NOT LOWER THAN 1’’ 1/4.
- The tubing must be suitable to functioning under back-pressure.
- Use tubing and accessories suitable for use with diesel fuel. Materials that
are not suitable for use with diesel fuel can cause damage to the pump, harm
people and cause pollution.
- Any curves in the suction pipes must be of the widest radius possible to limit
the loss of head.
- Make sure that the suction pipe is clean and free of scum.
