11 Model 327 Volumetric Line Leak 
Detector (VLLD) Sensor (only for 
Integra 500) 
OPW P/N: 30-3251 
 
Figure 11-1 Model 327 VLLD Sensor 
Designed to detect a leak in pressurized product piping by monitoring 
flow when the submersible pump is running and no one is dispensing 
fuel. The sensor utilizes an internal flow meter to detect and measure 
flow and provides an alarm condition if a leak is detected. An alarm 
condition will also occur if the cable is broken. The use of this sensor 
requires the addition of an external Line Interface Module (LIM) for up 
to four (4) STPs. 
NOTE: VLLD  sensors may  be multi-dropped  (maximum  three  (3) 
VLLD sensors). Cannot be multi-dropped with OPW probes/sensors 
on same I.S. channel. 
11.1 VLLD Specifications 
*Maximum Wiring Length is the maximum length of cable to be used 
to connect all sensors on an individual channel. The length includes 
run of cable from I.S. Barrier to each sensor board in the string. 
11.2 Prior to Installation 
Lock-out and tag-out the STP breaker and confirm all circuits are de-
energized. 
Completely barricade your work area. 
Adhere to OSHA Confined-Space Entry (CSE) protocol. 
Depressurize the product line. 
Keep plenty of fuel-absorbent material in the sump surrounding area.