6 Specifications That Matter Most for Stable Potting

1) Inner Diameter (ID) and Tolerance: the key to dosing accuracy

Metering pumps and valves are highly sensitive to ID consistency. Small ID variation changes flow resistance and shows up as:

• fluctuating dispense volume

• unstable pressure

• drift in mixing ratio (especially in 2K systems)

What to define: target ID, allowable tolerance, length consistency, and batch-to-batch stability.

2) Chemical compatibility: resin + solvent + cleaning agent

Don’t specify only “epoxy” or “silicone.” Compatibility depends on the full chemical set:

• resin type and additives

• thinners/diluents (if any)

• cleaning solvent and exposure time (flush vs. soak)

High-performance fluoropolymers (PTFE/PFA/FEP) typically handle chemical exposure better than many rubber/PU hoses that can swell, harden, or leach.

3) Temperature profile: evaluate heated zones separately

Potting systems often include heated tanks, line heating/insulation, and heated mixing heads. Tubing near heat sources can fail faster if the material is near its limit.

Best practice: treat heat-adjacent segments as a separate design zone:

• choose higher-temperature material

• add insulation or protective layering where needed

• avoid tight bends near heat sources

• 
  

4) Pressure and pulsation: depends on pump type

Gear, piston, and screw pumps create different pulsation patterns. Define:

• normal operating pressure

• peak pressure (including startup or blocked-line scenarios)

• pulsation severity

For challenging profiles, consider reinforced designs, protective jackets, or fittings with anti-blow-off features.

5) Bend radius and flex life: routing and motion matters

If tubing moves with XYZ axes, runs through a cable chain, or is routed in a tight enclosure, fatigue becomes a primary failure mode.

To improve service life:

• optimize wall thickness/OD

• add abrasion-resistant outer jackets

• use spring guards where repeated bending occurs

• consider a two-section design (fixed section + moving section)

6) Fittings and interfaces: don’t let the connection be the weak point

Even the best tube fails with mismatched fittings. Common interfaces include barbs, compression fittings, threaded fittings, and quick-connects.

What to provide: fitting type, size/spec, photos or drawings, sealing material requirements, and whether you need anti-leak / anti-blow-off measures.