50
Hose Failure Detection
One of the VERDER’s many advantages is the exceptional lifetime of the hoses. Normal wear
does take its toll on the hose and in time it will need to be exchanged for a new one. Throughout
the hose’s lifetime, it is essential that any possible failure is noticed in sufficient time to prevent
leakage into and damage to the pump housing and unit. Loss of flow can also be monitored as
a pre-failure indicator.
To prevent this, VERDER has developed a capacitive sensor to be screwed into the fill pipe. If a
hose does rupture, the liquid leaking into the housing will cause the fluid level to rise. Where the
level in the filler tube reaches the height of the sensor, an alarm sounds and either the motor
shuts down or the valves close automatically
Vacuum Equipment
When pumping highly viscous liquids, it may be necessary to create a vacuum inside the pump
housing to help the hose to regain its natural round profile, assisting suction capabilities and
ensuring the maximum flow rate
VERDER recommends the installation of a vacuum assist system for the VF25 - VF80 using an
electric or a pneumatic air-driven vacuum pump. The installation consists of a small vacuum
pump mounted on the pump frame, which evacuates the pump housing - the lowest pressure of
the pump must match the suction pressure of the hose pump. It is advised that a lowest
pressure possible manometer be installed at the suction side
Figure 24
When the vacuum assist unit has been installed, pulsation can still occur as it has no impact on
pulsation. If this also influences the efficiency of the flow adversely, VERDER recommends the
installation of a pulsation dampener (see above)
