Operating Description; Pumping, Filtration & By-Pass; Above Ground Tank Applications - Tokheim PAS V3 Component Technical Manual

Component Technical Manual
18) Air separation channel
19) High-pressure chamber
20) Drain and pressure plug
21) Outlet valve seat
22) Outlet valve
23) Outlet valve spring
24) Aeration valve
2.5

Operating Description

2.5.1
2.5.2
Document Ref 903647-001 Rev 3
PUMPING, FILTRATION & BY-PASS
The fuel held in the tank underground is raised by the gear pump [4] and passes
through the filter [3] and the foot valve [2].
The gear pump forces the product through the vortex system [17] into the high-
pressure chamber [19].
When the flow pressure exceeds the reference pressure, adjusted by the by-
pass screw, the by-pass valve [16] opens and the excess fuel in the high-pressure
chamber [19] is channelled back to the intake. Thus, the outlet pressure is kept
constant regardless of the flow drawn off by the fuel distribution hose(s).

ABOVE GROUND TANK APPLICATIONS

The PAS V3 pump has been specifically designed to work in conjuction with
underground tanks where the fuel level inside varies between 0.5 and 4 meters
below the pump shaft.
If the fuel in the tank can rise above this level, then we do not recommend you
use the PAS V3 pump.
Should there be no other option available, then the following precautions must be
taken:
1) Install a special "Tokheim 52 Valve" between the tank and the inlet of the
pump.
For VHS applications, you are required to use 2 of these valves in parallel.
2) Install a 1 in. solenoid valve between the tank and the inlet of the Tokheim 52
Valve.
For VHS applications, you are required to use 2 of these valves in parallel
The valve(s) should only be opened when the pump is running.
Note: This installation must be done in accordance with all local safety
legislation.
PAS V3 Pump for Fuel Dispensers
Page 2-5