Spectrophotometer manufacturer helped to solve problem in instrument flow cell with custom-designed tubing assembly with leak-tight gripper fittings
Omnifit has helped a spectrophotometer manufacturer solve a fluid transfer problem in the flow cells of one of its instruments by custom-designing a tubing assembly with leak-tight gripper fittings.
Each flow cell consists of a glass tube held in an aluminium housing.
The requirement was for a PTFE tubing assembly with fittings that would seal to the glass surface of the flow cell while accommodating variations in the alignment between the cell and its housing.
The dimensions of the flow cell tubing was 1.6mm OD and 1.0mm ID.
Each flow cell required two tubing assemblies, and due to the very tight space limitations on the top of the cell where the connections are made, the design also needed to ensure that it was easy for the operator to use.
The solution from Omnifit was a gripper fitting with a stainless steel case and a PTFE seal insert.
When assembled onto the glass tube of the cell, the PTFE 'cold flows', forming a secure seal on the glass surface.
There were slight variations in the alignment of the glass within the cell which could have made sealing difficult; this was overcome by fitting an O-ring between the gripper and the tube end fitting, allowing the gripper to align with the cell independently of any variations in the alignment of the housing.
The end of one fitting was also made slightly longer than the other to allow easy assembly, and the fittings were colour-coded for simple identification.
The initial prototypes were presented to the customer as e-drawings and animated CAD models.
These provided highly accurate information for assessment by the customer and also dramatically reduced the lead-time to the production of prototypes.
Omnifit has been a specialist designer and manufacturer of inert fluidic components for over 30 years.
Its custom products for instrument manufacturers include fittings, tubing sets, manual and electric valves, bottle caps and chromatography columns.
When designs are approved, Omnifit manufactures to meet the customer's supply chain requirements for scheduled, Kanban or JIT delivery.
