Pilot Plant Glassware — What to Specify and Where to Get It Made

The bench synthesis worked. The chemistry is validated, the yield is acceptable, the process parameters are understood. The next step is pilot plant — scaling from a 500ml flask to a 20L or 50L or 100L reactor to test the process at meaningful volume before committing to full production scale.

This is where most process development teams discover that their glassware supplier cannot follow them.

The catalogue stops at 5L or 10L for most standard items. The importer says custom fabrication at pilot scale requires a factory order with a 12-week lead time and a minimum of five units. The local supplier has never made anything above 10L.

Pilot plant glassware sits in a gap between bench-scale laboratory equipment and the large-scale process equipment supplied by turnkey engineering firms. It is too large for most laboratory glassware suppliers and too small — and too custom — for most industrial equipment manufacturers.

Understanding what to specify and where to source it is a practical engineering and procurement challenge. Here is a working guide.

What counts as pilot plant scale

There is no universal definition, but for borosilicate glass process equipment, pilot plant scale typically means:

• Reactor vessels from 10L to 200L
• Distillation assemblies handling similar volumes
• Associated equipment — condensers, receivers, separating vessels — scaled proportionally

Below 10L is generally considered bench or laboratory scale, well served by standard catalogue items. Above 200L in borosilicate glass is unusual — at very large scale, other materials (glass-lined steel, for example) are typically more practical.

The 10L to 200L range is where pilot plant glass fabrication sits, and where the supplier gap is most acute.

Key specifications for pilot plant glassware

Capacity and geometry. The working volume of the vessel — not just the nominal capacity. A 50L round bottom flask has a nominal capacity of 50L but a practical working volume of 35–40L. Specify the working volume you need and let the manufacturer size the vessel accordingly, or specify nominal capacity with working volume noted.

Jacket configuration. Pilot plant reactors typically require temperature control — either heating or cooling. A jacketed vessel has an outer glass jacket through which heating or cooling fluid circulates. Specify whether a jacket is required, the jacket inlet and outlet port sizes, and the temperature range the vessel will operate at.

Port configuration. How many necks does the vessel need, and what size? Standard ground glass joints (NS sizes — NS 29/32, NS 45/40, NS 60/46 are common at pilot scale) allow standard fittings. Non-standard port positions — side ports at specific angles, bottom outlets, additional sampling ports — must be specified explicitly.

Material specification. Borosilicate 3.3 to ISO 3585 for laboratory and pharmaceutical pilot applications. Confirm this with the manufacturer and ask for material documentation.

Wall thickness. At pilot scale, wall thickness affects both structural integrity and thermal performance. Thicker walls provide more mechanical strength but reduce thermal transfer rates. For most pilot plant applications, standard wall thickness for the vessel diameter is appropriate — but if your process has specific requirements (high pressure, rapid thermal cycling), specify them.

Connection standards. Ground glass joints, flanged connections, or other fittings — and the sizes required — must be specified to ensure compatibility with existing equipment.

What to provide to a manufacturer

For most pilot plant glassware, a hand sketch with key dimensions is sufficient to get a feasibility response and quotation. The sketch should show:

• Overall vessel shape and approximate proportions
• Capacity (nominal or working volume)
• Number and position of necks/ports with joint sizes
• Jacket configuration if required (inlet/outlet positions)
• Any non-standard features

A CAD drawing in DXF or PDF format is preferable for complex assemblies or where dimensional precision is critical. For simpler vessels, a dimensioned sketch works well and is faster to produce.

Include the operating conditions — temperature range, whether the vessel will be under vacuum or pressure, the chemical environment — so the manufacturer can confirm suitability.

Finding a manufacturer who can work at pilot scale

The filtering question is simple: what is the largest single piece you have fabricated, and what is your standard capability at pilot scale?

A manufacturer whose largest piece is a 5L flask is not a pilot plant supplier. A manufacturer who routinely fabricates 20L, 50L, and 100L vessels — and has demonstrated capability up to 200L or beyond — has the equipment, the skills, and the process knowledge to handle pilot plant work.

In India, genuine pilot-scale borosilicate glass fabrication capability is concentrated in a small number of manufacturers. When evaluating them, ask for:

• Examples of pilot-scale work they have completed (photographs of fabricated vessels with capacity noted)
• Maximum capacity they can fabricate in a single piece
• Lead time for a custom pilot-scale vessel
• Quality documentation — ISO certification, material certificates

For buyers in the Telangana and Andhra Pradesh pharma corridor, proximity matters at pilot scale. Large vessels are fragile in transit. A manufacturer in the same city means shorter handling distance, lower breakage risk, and the ability to inspect the vessel before dispatch.

Assembly and commissioning considerations

Pilot plant glassware rarely ships as individual components. A complete pilot plant setup includes the reactor vessel, jacket connections, condenser, receiver, overhead stirrer mount, and associated adapters and fittings — all of which need to fit together and connect to the plant utilities.

Some manufacturers can fabricate and supply matched assemblies — pieces designed to work together dimensionally. This is preferable to sourcing components from multiple suppliers and discovering fit issues on installation.

When ordering a pilot plant assembly, provide the overall setup drawing or describe the full assembly. Ask the manufacturer to confirm that all components are dimensionally compatible before fabrication begins.

The pilot plant is where the process is validated before full production investment. Getting the glassware right at this stage — correct configuration, correct scale, correctly assembled — is worth the time spent on specification upfront.