Solenoid-operated gas valve delivers a more compact, cost-effective solution for smart meter supplier
Size of project:
NSF Controls has produced over 4.5 million of these assembilies with no field failures.
Scope of Service:
- New product development
- Parts procurement
- Supply chain management
- Risk Analysis
- Electro-mechanical assembly
- Quality control
Initially, Landis+Gyr, which supplies energy measurement solutions for utilities including electricity, gas and water, contacted NSF Controls with a view to redesigning an existing gas valve for its pre-payment meters. The company had experienced challenges with its incumbent supplier and was looking to improve the unit’s design without altering its function.
For NSF Controls, the challenge presented was to re-design the unit. It had to remain cost competitive from a manufacturing perspective and also, was required to meet both size and budget restraints; ideally being re-designed in a smaller, lighter format, with reliability being key.
To check functionality, the starting point for the replacement was to take one of NSF Controls’ standard solenoids. NSF Controls’ application engineers adapted the magnetic latching solenoid, originally used in Economy 7 electricity meters, in conjunction with a similar sealing method to that already in use.
Adapting and overcoming a pending patent
Overcoming the existing supplier’s pending patent for the way in which the sealing mechanism was arranged, had to be considered. The solution was to introduce additional components, requiring an increase in performance from the solenoid, and a combination of circlips and springs.
Increased solenoid performance was achieved using an extended - literally longer - version of the replacement solenoid. It had the same cross-sectional frame size with a longer coil resulting in higher forces.
The solenoid needed over-travel to ensure it was latched and the seal was pressurised against the sealing face. It was a balance between the amount of energy available and the forces needed to overcome resistance from gas flow pressure and springs.
Reducing unit size and mass
Achieving a considerably reduced unit size and mass, the new solenoid arrangement was then fitted to the existing inlet manifold.
On-going development of the meter by the customer meant that the whole configuration of valve and measuring tube was re-assessed. The resulting challenge was to address the major change of sealing with the flow and opening against it. This needed critical balancing of the spring and solenoid forces and gave rise to the development of a bayonet-type interface with the metering tube and sealing face.
A suitable dust filter bag was sourced to replace the dust bowl and bag previously used, in a belt and braces approach.
The results and future
More compact and cost-effective unit
With an 80% reduction in weight and no impact on performance, the design improvements applied to the gas valve assembly provided NSF Controls’ customer with a more compact, cost-effective unit.
From design to manufacture and more
To support the customer’s required volumes, NSF Controls introduced semi-automated assembly lines, incorporating automated test equipment, as well as its robust logistics infrastructure. This production facility currently has a capacity in excess of 30K gas valve assemblies a week. NSF Controls has produced over 4.5 million of these assemblies with no field failures.
A productive working partnership is now in place and further development work in progress.
Click here to find out more about NSF Controls solenoids
For replacements and prototype activity a selection of NSF Controls Tubular Solenoids are now available to buy from Amazon.