Page 4-4
Document Ref 903647-001 Rev 3
PAS V3 Pump for Fuel Dispensers
Component Technical Manual
Issue B
4.5
External Problems up-stream the PAS
1)
If there is a non-return valve, check its proper operation.
*Defective non-return valve (if mounted according to dispenser model):
Replace the valve.
2)
Check the volume meter is not blocked
*If blocked, replace the volume meter.
3)
Check condition of the nozzle filter and of the nozzle
*Filter of the nozzle clogged. Clean filter when necessary.
4)
Check whether the electronic valve is working
*Electronic valve is blocked. Replace the electronic valve.
4.6
Excessive Head Loss
When the ambient temperature increases, the ability to pump fuel is reduced (formation
of vapour locks): check if the pipe work and manifold are sufficiently insulated (as installed)
from ambient heat sources.
To reduce the temperature build-up the manhole chimneys can be filled with sand and the
manhole covers can be painted white.
If a satisfactory technical solution cannot be found, try to maintain normal operation by
keeping the storage tank filled as much as possible, this will reduce problems coming
from high ambient temperatures.
1)
Check the head loss resulting from the specific configuration of each fuel line by comparing
the measured head loss under each dispenser at the point where the same fuel from the
same underground storage tank arrives.
•
If these various measured head loss values are comparable:
⇒
Check the expected (theoretical) head loss values are indeed comparable to those
measured. If not the line may be obstructed by an unknown object.
•
If these various measured head loss values are not comparable:
⇒
Check the connection between each PAS and the relevant underground pipe work
(manifold, non-return valve blocked).
2)
Check the PAS filter.
3)
If the dispenser is the only one delivering this product, check the complete line, noting the
distance between the pump and the storage tank (take care of the way of piping), the
height of the product in the tank, the various accessories (plugs, valves, and so on). Usually
an easy way to solve the problem is to fill the tank before trying to cool down the fuel.
