Sofis recently supplied FlexiDrive remote valve operators to the INS Vikrant, an aircraft carrier in service with the Indian Navy. The remote valve operators are part of the ship’s HVAC system. This system was supplied and installed by Johnson Controls, one of the world’s biggest suppliers of HVAC/R (heating, ventilation, air conditioning, and refrigeration) solutions for marine and naval applications.
Maintaining watertight integrity
HVAC systems regulate and move heated and cooled air throughout the ship, where ducts carry the air. As ducts are connected throughout the ship, water can easily find its way from one section to the other, and to the rest of the ship. Therefore, to maintain the watertight integrity of the ship sections, shut-off valves are to be installed on ducts. Initially, design engineers at Johnson Controls considered installing valves on each side of watertight sections, allowing safe operation from the side that is not flooded. However, this potential solution would increase costs and add considerable weight to the ship so other options were evaluated. One such option was to operate one single valve from either side of the bulkhead, using a physical connection of rods and bevel gears. Again, operating and maintaining these kinds of systems is costly in addition to the need to replace rods and bevels after five to ten years due to wear and tear.
Operating manual valves from a safe distance
The design team of Johnson Controls realized that in case of severe flooding, shut-off valves on ducts should ideally be operated remotely. To prevent safety breaches, it was therefore decided that duct valves were to be equipped with remote valve operators. This way, valves can be operated from a safe distance in case of flooding. Johnson Controls was looking for flexibility in terms of component breakdown, and this led them to the Sofis FlexiDrive. Instead of rods, FlexiDrive uses a flexible cable, that can be bent to any desirable position.
Physical shock testing
After getting clearance to install FlexiDrive onboard on INS Vikrant, Johnson Controls continued with complementary shock testing, to prove that the system would still work after applying considerable mechanical shock. Test results were positive, proving FlexiDrive (which also has an IP68 and ABS design certification), to be ready for use onboard INS Vikrant.
Close cooperation
Hundreds of duct valves have already been equipped with FlexiDrives by Johnson Controls engineers after having received in-depth installation training from Sofis service engineers. For weeks, a fully dedicated Sofis service engineer closely cooperated with Johnson Controls engineers, helping them install FlexiDrives on board INS Vikrant, and providing on-the-job training. This allowed Johnson Controls engineers to quickly improve their installation and problem-solving skills.
Positive feedback
Johnson Controls has received positive feedback from the Indian Navy. FlexiDrive systems are being operated daily and the solution is also relied upon when using other systems, where manual valves are not in an easy and accessible position. The FlexiDrive system has proven to be reliable, providing ease of operation of hard-to-reach manual valves. Over a hundred extra FlexiDrives have already been fitted on other ‘typical’ manual valve systems, such as oil valves located in hard-to-reach areas of the ship. As a result of their positive impact, FlexiDrive remote valve operators are now also being used on other ships of the Indian Navy, including another aircraft carrier.
Offering FlexiDrive by standard
As a direct result of their positive experiences, Johnson Control now offers FlexiDrive as a standard solution for operating duct valves on ships, when valves must be operated from both sides of a watertight ship section.