NBTA Alert - Internal Shut Off Valves (Footvalve) Open in Transit
Internal Shut Off Valves (Footvalve) Open in Transit
Recent consultation associated with the revision of AS5602 has highlighted a concern that some road tankers may be operating with internal valves either held open or unsealed while in transit. Valves could remain unsealed in transit due to the following (including, but not limited to):
- Footvalve seal damaged or missing
- Top operator/camlift being held in the open position (either seized or manually opened)
- Actuator failure, shaft being jammed or seized
- Foreign object jammed in the footvalve preventing closure (bolts, pens, lift wire, etc.)
- Mechanical failure of the actuating spring or cross shaft (broken, dislodged or jammed)
In Service Testing Practice
As per AS2809 Part 1, Section 3 Vehicle Inspection, valve interlock function is required to be inspected every three months.
In addition to periodic AS2809 Inspections, it is best practice to regularly check footvalves are sealing.
Drivers should regularly check footvalves are sealing during a gravity discharge by following these simple steps
• Open the drive away protection mechanism
• Connect delivery hose to the delivery point as per normal process
• Leave footvalves closed and open the API valve to discharge pipework
• Once the initial discharge of the pipework is observed (this will vary dependant on pipework length and angle and may take 1-2 minutes), continue to monitor the sight glass for NO further flow of product
No further product flow should be observed. Any further product flow observed indicates a leaking or jammed open footvalve that requires rectification.
This is a recommended practice, however, several other methods can also be used to check correct footvalve operation. For tankers not fitted with sight glasses, further guidance can be provided.
The footvalve is the primary closure. Its only purpose is to ensure product stays within the tanker in the event of a damaged pipeline. The footvalve is the only thing retaining the contents of the whole compartment(s) and as is therefore a critical safety component that must be operating correctly.
Please do not hesitate to contact the National Bulk Tanker Association should you wish to discuss this further.
