1
5
Installation
Figur
e
13
EXPANSION JOINT
EXPANSION JOINT
CHECK VALVE
Installation
5.7
Expansion Joint
Dimensional changes in piping and equipment, caused by variations in the working temperature of the piping system and the
pump, either by the temperature of the pumped fluid or by exposure to changing environmental conditions, result in large
magnitude stresses and forces that are transmitted to the pumping equipment and can damage it. That is why VOGT S.A.,
recommends the use of expansion joints as part of the piping system that connects to the pump, when conditions warrant it, see
figure 13.
Even though the absorption of axial movements, caused by temperature changes, is the main work performed by the expansion
joints, they also act as vibration isolators reducing the propagation of vibrations, produced by the operation of the equipment,
through the piping system and also act as compensators of lateral, angular and torsional movements.
Start-up
Start-up
A self-priming pump must be primed at the first start-up or in very spaced runs. Priming consists of filling only the pump
body with the liquid to be pumped. When the pump starts operating, the design of the pump causes the liquid contained in it
to start producing a vacuum that extracts the air from the suction pipe and the liquid starts to rise, after a few minutes it
reaches the pump and normal pumping starts.
When the pump stops the liquid can be suspended by the check valve and the pump is primed, this allows it to pump
immediately when it starts up again.
