Name: Filtering Flask
Brand: RichTech

Specifications

Filtering Flask · Specifications

Standard capacity ranges below. Custom capacities and special specifications available upon request.

Capacity (mL)	O.D. (mm)	Height (mm)	Neck I.D. (mm)	Side-Arm O.D. (mm)
250	82	155	30	8
500	102	190	36	8
1000	130	240	42	10
2000	166	290	50	10
3000	190	330	55	12
5000	230	390	62	12

* Custom capacities and special specifications available. Contact us for details.
* Filtering flasks feature a standard side-arm compatible with standard vacuum tubing.
* Recommended for use with Buchner or fritted funnels — please consult our sales team for proper sizing.

Capacity (mL)	Joint Size
50	14#
100	14#
50	19#
100	19#
250	19#
500	19#
250	24#
500	24#
1000	24#
500	29#
1000	29#

Product Description

The filtering flask is specifically designed for vacuum filtration, featuring a side-arm for connection to a vacuum pump for rapid solid-liquid separation. The thickened wall design withstands vacuum pressure, making it widely used in chemical, pharmaceutical, and environmental testing laboratories.

Four Series · Flexible Selection

RichTech offers flasks in Erlenmeyer, Filtering, Round-Bottom, and Flat-Bottom series:

1. Erlenmeyer Flasks (Standard Conical)

Conical design with wide base and narrow mouth for easy mixing and storage.
Narrow mouth effectively reduces evaporation and splashing, ideal for titration.
Suitable for titration analysis, heating reactions, and media preparation.

2. Filtering Flasks (Side-Arm)

Features a side-arm for connection to a vacuum pump for filtration.
Uniform wall thickness to withstand vacuum pressure.
Used with Buchner or fritted funnels for solid-liquid separation.

3. Round-Bottom Flasks

Round-bottom design for even heat distribution, ideal for reflux and distillation.
Requires heating mantle or oil bath — not for use on hot plates.
Used in organic synthesis, reflux reactions, and distillation.

4. Flat-Bottom Flasks

Flat bottom for stable placement on hot plates or workbenches.
Combines the narrow mouth of a flask with the stability of a beaker.
Suitable for heating reactions, solution preparation, and general storage.

Design Features

Side-Arm: Enables connection to a vacuum pump for rapid filtration, significantly improving efficiency.
Thickened Wall: Uniformly thickened design withstands vacuum pressure for safe operation.
Conical Body: Wide base with moderate neck for easy filtrate collection and process observation.
Uniform Wall Thickness: Even thickness distributes stress, improving vacuum resistance.

Material Advantage

Manufactured from Borosilicate Glass 3.3 in accordance with ISO 3585 standards. The ultra-low coefficient of thermal expansion (3.3×10⁻⁶/K) ensures resistance to thermal shock up to 280°C, with excellent chemical resistance for long-term contact with acids and bases.

Quality Assurance

Every piece undergoes rigorous dimensional inspection, stress testing, and pressure testing to meet high laboratory standards, providing reliable performance for your filtration operations.

Note: Inspect the side-arm and walls for cracks before use. Ensure the vacuum connection is secure to prevent leaks. Do not heat filtering flasks — heating may compromise vacuum resistance.

Applications

Common Configurations

Buchner Funnel + Filtering Flask Rapid solid-liquid separation, crystal collection
Fritted Funnel + Filtering Flask Precision filtration, micro-analysis
Vacuum Pump + Filtering Flask Vacuum filtration for increased speed
Filter Paper + Buchner Funnel + Flask Standard vacuum filtration setup

Specific Applications

Crystal Isolation

Rapid collection and washing of reaction products

Precipitate Collection

Separation of precipitates in chemical analysis

Solid-Liquid Separation

Quick filtration of suspensions and cloudy liquids

Sample Preparation

Filtration pretreatment for environmental water and food samples

Pharmaceutical Manufacturing

Separation and purification of API intermediates

Teaching Labs

Basic chemistry and pharmacy laboratory instruction

Environmental Monitoring

Suspended solids determination in water samples

Quality Control

Filtration operations for product purity testing

Tip: When using a Buchner funnel with a filtering flask, select filter paper that matches the funnel size. Pre-wet the filter paper and apply vacuum to seat it properly before adding the sample for optimal filtration efficiency and filtrate clarity.

Filtering Flask Procedure

03

Preparation

Inspect the filtering flask for cracks, scratches, or other defects, especially around the side-arm connection.
Select a Buchner funnel or fritted funnel that matches the flask neck size for a proper seal.
Place filter paper in the Buchner funnel, wet with a small amount of solvent, and apply vacuum to seat it against the funnel wall.
Connect the vacuum pump to the side-arm with secure, leak-free tubing.

04

Filtration Operation

Start the vacuum pump, allow the system to stabilize, then pour the liquid slowly into the funnel using a glass rod as a guide.
Do not fill the funnel beyond the rim — liquid may overflow.
Add liquid periodically to maintain filtration, but avoid letting the funnel run dry between additions to prevent filter cake cracking.
After filtration is complete, turn off the vacuum pump, then slowly release the vacuum to prevent backflow.
Wash the filter cake with a small amount of solvent to remove residual mother liquor.

05

Backflow Prevention

Install a safety trap (buffer flask) between the filtering flask and vacuum pump to prevent liquid from entering the pump.
When stopping filtration, disconnect the vacuum tubing or open the vent valve before turning off the pump to prevent backflow.
For volatile solvents, use a cold trap or absorption flask between the safety trap and pump.

06

Cleaning & Maintenance

Clean promptly after use to prevent residue from drying and hardening.
Use dilute acid or specialized cleaning agents for stubborn residues.
Rinse with distilled water and air-dry upside down on a drying rack.
Store carefully to avoid chipping and breakage.

Tip: Filtering flasks are essential tools for solid-liquid separation. Proper use and maintenance significantly extend service life. We recommend installing a safety trap between the flask and vacuum pump to prevent backflow damage.

Care & Notes

Show care & notes

Safety Notes

Inspect flasks for cracks or scratches before use — damaged glass may fail under vacuum.
Always release vacuum before turning off the pump to prevent backflow.
Handle with care, especially around the side-arm connection.

Do not

Do not heat filtering flasks — heating reduces vacuum resistance.
Apply vacuum gradually — do not apply full vacuum instantly.