Specifications

Constant-Pressure Column · Specifications

Standard sizes are listed below. All products comply with GB/T, ASTM, and ISO standard taper systems. Full range 10/19 ~ 60/45 available. Custom IDs, effective lengths, wall thicknesses, and frit grades are available.

Request custom specs

1. Standard Constant-Pressure Column Sizes

Note: Wall thickness is standard; thicker walls available for higher pressure requirements. Vacuum barb is 8mm O.D. standard.

ID (mm)	OD (mm) approx.	Effective Length (mm)	Common Joint	Wall Thickness (mm)	Frit	Stopcock	Vacuum Barb	Separation Scale
10 ~ 13.4	13 ~ 17	200 / 305 / 457	14# / 19# / 24#	1.8 ~ 2.0	Optional	Optional	Optional	Micro
16 ~ 20	20 ~ 26	203 / 305 / 457	19# / 24#	2.0 ~ 3.0	Optional	Optional	Optional	Small
26 ~ 32	32 ~ 40	203 / 254 / 305 / 457	24# / 29# / 35/20	2.5 ~ 3.5	Optional	Standard	Standard	Medium
40 ~ 46	46 ~ 53	203 / 305 / 457	19# / 22# / 24#	3.0 ~ 4.0	Optional	Standard	Standard	Preparative
53 ~ 60	60 ~ 67	203 / 254 / 305 / 457	24# / 29#	3.5 ~ 4.5	Optional	Standard	Standard	Large-scale
73 ~ 80	80 ~ 87	203 / 305 / 457 / 610	24# / 29#	3.5 ~ 4.5	Optional	Standard	Standard	Batch
90 ~ 100	100 ~ 110	300 / 400 / 500 / 600	24# / 29# / 34#	4.0 ~ 5.0	Optional	Standard	Standard	Industrial
100+	110+	300 / 500 / 700 / 1000 / 1500	24# / 29# / 34# / 40#	4.5+	Optional	Standard	Standard	Mass Production

2. Constant-Pressure vs Standard Column Comparison

Feature	Standard Column	Constant-Pressure Column
Wall Thickness	Standard (1.5-2.5mm)	Thick-Wall (3.0-4.5mm)
Pressure Resistance	Atmospheric	Pressurized / Vacuum
Separation Speed	Standard flow	Significantly faster (3-5×)
Typical Use	Standard chromatography	Flash chromatography, rapid purification
Additional Features	None	Vacuum barb (optional)

3. Standard Joint Specifications (GB/ASTM/ISO)

GB/T	ASTM	ISO
14#	14/20	14/23
19#	19/22	19/26
24#	24/40	24/29
29#	29/42	29/32
34#	34/45	34/35
40#	40/50	40/38

* Joint numbers (14#, 19#) indicate the largest diameter (mm) of the taper. All are 1:10 taper.
* GB/ASTM/ISO designations are different standard identifiers — physical dimensions are identical and fully interchangeable.
* Wall thickness can be customized up to 6mm for higher pressure requirements.
* Frit grades: G1/G2/G3/G4 available.
* Vacuum barb is 8mm O.D. standard.
* Contact our sales team for MOQ and lead time on custom orders.

✦ Customization Services — We offer custom IDs, effective lengths, wall thicknesses, frit grades, and joint configurations. Share your specific requirements and our technical team will provide a tailored solution.

Product Description

The constant-pressure column (flash chromatography column) is specifically designed for pressurized or vacuum-assisted operation. With a thick-wall construction, it can withstand higher operating pressures, significantly increasing separation speed and reducing purification time — making it the ideal choice for rapid purification, preparative separations, and industrial production.

Manufactured from high-borosilicate glass 3.3, the column offers excellent clarity for real-time observation of bed status and sample migration. The upper end features a standard taper joint for connection to solvent reservoirs, pressure equipment, or constant-pressure funnels. Equipped with a PTFE stopcock for precise flow control — resistant to strong acids/bases with no lubrication required. Select models feature a 8mm vacuum barb for connection to vacuum pumps, enabling vacuum-assisted flash chromatography for even faster separation.

✦ Key Advantage: Thick-wall design (3.0~4.5mm) significantly improves pressure resistance, supporting both pressurized and vacuum operations — separation speeds can be increased by 3-5 times compared to standard columns.

Key Features

Borosilicate Glass 3.3: Meets ISO 3585, low thermal expansion, thermal shock resistance up to 280°C, excellent chemical durability
Multi‑Standard Compliance: Precision‑ground 1:10 taper meets GB/T, ASTM E, and ISO 3585 standard taper specifications for full interchangeability
Thick-Wall Design: Wall thickness 3.0~4.5mm, significantly improved pressure resistance, supports pressurized and vacuum operations
PTFE Stopcock: Resists strong acids/bases, no lubrication required, precise flow control, excellent sealing
Vacuum Barb: 8mm barb on select models for connection to vacuum pumps, enabling vacuum-assisted flash chromatography
Optional Frit: Built-in G2/G3 sintered frit available to prevent packing loss and simplify column packing

Quality Assurance

Each constant-pressure column is inspected for dimensional accuracy, wall thickness uniformity, taper precision, and pressure resistance testing to ensure reliable sealing with all standard joint components. Custom bulk orders are welcome.

Tip: Constant-pressure columns are designed for pressurized or vacuum-assisted operation. Monitor pressure limits carefully. Ensure all connections are sealed before pressurization. Consider adding protective guards for high-pressure operation.

Applications

Typical Uses

Flash Chromatography

Pressurized operation for rapid separation — 3-5× efficiency improvement

Vacuum Chromatography

Connect to vacuum pumps for vacuum-assisted flash, ideal for difficult separations

Preparative Purification

Rapid purification of large-scale samples

Natural Product Isolation

Rapid separation of complex natural products

Industrial Production

Purification in batch production processes

Pharmaceutical Purification

Rapid purification in pharmaceutical manufacturing

Compatible Equipment

Standard joint solvent reservoirs, constant-pressure funnels

Pressure equipment (air pumps, peristaltic pumps)

Vacuum pumps (vacuum models)

Ring stands and clamps (specialized supports for extra-long columns)

Fraction collectors

Tip: The thick-wall design of constant-pressure columns allows them to withstand higher operating pressures. Always use matching standard joint sizes for optimal sealing. Monitor pressure during operation to avoid exceeding limits.

Operation & Maintenance

User Guide

Before Use

Inspect for cracks, chips, or scratches on any joint
Confirm wall thickness meets pressure requirements
Check that the frit (if present) is intact
Clean all joint surfaces with a soft cloth to remove particulates
Confirm that the joint size matches your accessories
Prepare packing material, eluent, and collection vessels
Prepare pressure equipment (air pump/peristaltic pump) or vacuum pump

Packing Procedure

Mount the column vertically on a stand or specialized support
Close the PTFE stopcock
Add a small volume of eluent to wet the column (or frit)
Slowly add packing material while gently tapping the column for even settling
Add a layer of glass wool or filter paper on top of the packing
Connect pressure equipment or vacuum pump

Flash Chromatography Operation

Pressure Mode: Connect the upper joint to an air pump or peristaltic pump, adjust pressure to control flow rate
Vacuum Mode: Connect the vacuum barb to a vacuum pump, adjust vacuum level to control flow rate
Apply the sample and begin elution
Collect fractions based on the separation profile
Monitor pressure to avoid exceeding limits

Cleaning & Storage

Rinse immediately after use with appropriate solvent
For clogged frits, use ultrasonic cleaning or back-flushing
Use soft brushes and appropriate detergents for the tube interior
Air dry and store with protective paper between ground joints
Protect the frit and joints from impacts