4
PUTTING INTO SERVICE
The
ZVA Slimline 2 GR
is a fuel-dispensing nozzle with an automatic safety shut off for wet-hose
use with electrical operated petrol dispensing pumps for the 'active' vapour recovery. Working
pressure 0,5 up to 3,5 bar, temperature range -20° C up to +55° C ( LT type -40° C up to +55° C ).
The
ZVA Slimline 2 GR
fulfils the conditions of the European Weights and Measures as well as
EN 13012. TÜV approvals and ATEX certificate (category Ex II 1G) s. pages 14-15. Each nozzle has
been subjected to stringent tests before leaving the factory and validated by the applied markings
and date code.
The
ZVA Slimline 2 GR
is supplied ready for connection to the COAX hose. After assembling and
switching on the pump, point the spout vertically towards the ground and operate the lever (9)
several times to vent air from hose and nozzle. Carry out a complete functional testing of the
nozzle. Then check :
Is the nozzle, hose connection and COAX swivel tight under pressure?
Does the pump switch off when returning the nozzle back into the nozzle boot?
Does the vapour recovery system function according to regulations? For a simple 'YES / NO'
functionality check the Quick Tester GR 92 may be used.
For a proper calibration and functionality check of the vapour return, additional requirements for
each vapour recovery system must be taken into consideration.
MAINTENANCE
The nozzle does not require any lubrication.
Safety checks
: Regularly inspect the nozzle visually for damage. Pay attention that the spout
serration secures the nozzle in the filler neck. Test the 'minimum' shut off and the safety cut off
function (3) during the annual pump maintenance, or in case of damages which may effect the
vacuum.
IN CASE OF TROUBLE
IF THE NOZZLE FAILS TO OPEN
:
The pump pressure may be too low to push the valve
poppet open. In hot weather, dirt and gum deposits can also cause stickage and valve seat (6).
If the pump pressure cannot be increased, disconnect the ZVA, remove the swivel, remove COAX
vapour insert, pull the lever to the open position and push the valve stem to free the poppet (7).
IF THE NOZZLE DOES NOT CLOSE AUTOMATICALLY
: The vacuum required to operate the
automatic action is too low. With the pump running, fully pull the lever (9) to check that full flow
can be obtained. Also check, if a loose spout, damaged vacuum cap (5) or clogged strainer (8)
have caused the pressure drop.
IF THE ZVA KEEPS TRIPPING OFF IMMEDIATELY
: The air passage is blocked (2). First
check if it is caused by the ball of the safety cut off by shaking the nozzle. If the ball is free to
move, it will rattle. To clear the air passage blow compressed air up the spout until air comes out
of the sensing port (1).
IF YOU CANNOT MAKE IT WORK
:
Call your service contractor. They have the skills and parts
needed to restore working order.
HOW THE ZVA AUTOMATIC WORKS
The flow through the nozzle creates a vacuum at the valve seat (6). Air is drawn in through the
sensing port (1) at the tip of the spout, through the safety cut-out, past the diaphragm, and into the
fuel. The valve will remain open while the air flows freely. When fuel reaches the sensing port, suction
builds up rapidly until it lifts the diaphragm (4) and trips the automatic action which shuts the valve.
The mechanism also trips if the ball of the safety cut-out (3) rolls back to obstruct the free air
flow. It will also occur if the spout is pointed upwards or if the nozzle is dropped onto the ground.
The valve opens with the flow, allowing smooth flow control for 'to-the-penny-dispensing'.
It closes against the flow for a 'soft' shockless closure.
Description see page 16
