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Reactor Inspection Checklist: How to Evaluate Used Glass Reactors for Scale-Up Projects

Why reactor inspection matters in scale-up environments

In chemical processing and engineering, reactors are not just lab tools—they’re capital equipment that determines scale-up success. A flawed reactor can introduce:

• safety risks
• batch failures
• contamination
• costly downtime

Used glass-lined or borosilicate reactors can offer tremendous value, especially for pilot plants—but only if properly inspected. This guide gives you a practical checklist focused on real-world scale-up risk points.

Step 1: Inspect the glass body for stress cracks and microfractures

Glass reactors fail in predictable ways. The biggest risk is stress-related damage from:

• thermal shock
• over-tightened clamps
• mechanical impact
• previous overpressure events

What to look for

• hairline cracks near joints and nozzles
• cloudy or “spider web” patterns
• stress whitening around clamp zones
• chips along flange edges

Use:

• bright directional light
• slow rotation inspection
• magnification where possible

Red flag: any crack near a nozzle or bottom outlet, these are high stress zones.

Step 2: Verify jacket integrity and pressure ratings

For scale-up, the jacket is just as critical as the vessel.

Why this matters

The jacket determines:

• heating/cooling rate
• thermal uniformity
• pressure safety margins

What to confirm

• manufacturer nameplate (if present)
• jacket pressure rating (positive and vacuum)
• compatible thermal fluid ranges
• previous operating conditions (if known)

If documentation is missing, assume conservative operating limits and verify via supplier or manufacturer where possible. Explore our inventory.

Step 3: Check nozzle alignment and mechanical stress points

Nozzles often suffer damage during shipping or improper rigging.

Inspect:

• top ports (stirrers, thermowells, additions)
• side ports (sampling, feed lines)
• flange flatness and sealing surfaces

Misaligned nozzles can lead to:

• poor sealing
• gasket failure
• uneven mechanical loading

Step 4: Bottom drain valve inspection (the most overlooked failure point)

Bottom outlets are heavily used and frequently abused.

What to inspect

• valve smoothness (no grinding or sticking)
• PTFE plug condition (for glass/PTFE valves)
• sealing surface wear
• signs of crystallized product buildup
• actuator integrity (manual or pneumatic)

Why it matters
A failing bottom valve can:

• contaminate product
• cause leaks mid-batch
• create cleaning nightmares

For scale-up workflows, bottom valve reliability is non-negotiable.

Step 5: Inspect the support frame and mechanical assembly

A glass reactor is only as stable as its support structure.

Check:

• frame corrosion or bending
• caster integrity (if mobile)
• lifting points
• alignment of support rings

Mechanical instability increases:

• glass stress
• operator risk
• vibration during mixing

Step 6: Agitator and drive compatibility

Even if drives are purchased separately, confirm:

• stirrer shaft compatibility
• seal condition (mechanical vs PTFE packing)
• motor mount alignment
• torque capacity for viscous scale-up

Underpowered drives are a common scale-up bottleneck.

Used reactor documentation checklist

Ask the seller for:

• manufacturer and model
• original volume rating
• jacket pressure specs
• service history
• previous chemistry (corrosion risk)

Even partial documentation improves confidence.

Common deal-breakers

Avoid reactors with:

• structural glass cracks
• unknown high-pressure history
• severely worn bottom valves
• heavily corroded frames

These issues rarely justify repair at pilot scale.

FAQ

Can small scratches in glass be acceptable?
Superficial scratches may be acceptable depending on location, but any structural crack near stress points should be treated as a rejection.

Is older glass inherently unsafe?
Age alone isn’t the issue—operating history and handling matter more.

Need help?
If you’re evaluating used glass reactors for pilot or kilo lab work, send HiTechTrader the size, chemistry type, and temperature range. We can help you identify reactors suitable for scale-up with minimal risk. Click here to contact HiTechTrader.