Feedback sensors are essential for ensuring critical valves are appropriately positioned when in service.
Modulating control valves use a positioner to transmit a feedback of their status to the plant control system.
What about the position of manual lever-operated valves though? How can you tell if they are correctly positioned at all times?
Manually-operated valves can (1) accidentally be left open when they should be closed and (2) vice versa. Additionally (3) it might be required that the valve position, if changed, should activate an alarm at the plant control system
Examples of this might be:
- Spring return or drain valves
- Valves for critical isolation
- Activation of a safety shower
Manufacturers generally cater for a standard VDI/VDE 3845 mounting suitable for the majority of valve actuators, however for manual lever-operated valves, methods for mounting feedback devices have until now tended to be the addition of a completely-enclosed switchbox. These can be expensive to purchase, can incur considerable installation costs and, due to their size, can sometimes be difficult or impossible to fit in-situ.
Solution:
Where manual lever-operated valves are required to be able to feed back valve position, ESI are able to supply a simple, yet innovative mounting solution: two integral sensors housed in a robust casing, and a round switch target known as a “puck” which is fitted with two metal pick-ups, at varying heights & and 90° apart, providing detection by the upper and lower sensors, for open / closed feedback:
A manual lever-operated ball valve in the closed position, showing one of the puck pick-ups lined-up with the proximity sensor.
The same manual lever-operated ball valve in the open position, showing the second of the puck pick-ups lined-up with the proximity sensor.
The advantages:
- Effective feedback for monitoring of on-site valves
- Compact, particularly useful where space is limited
- Cost effective when compared with traditional enclosed switchbox
- Simple installation
- Hi-visibility coloured puck providing visual indication in situ
- Low maintenance
- A variety of voltage options, IP and ATEX ratings available according to individual customer requirements
For further information on the puck-sensor solution to monitoring manual lever-controlled ball valves contact us in UK +44 1633 877505, Ire +353 21 4510900 or send us a product enquiry via form or chat.