Teflon gas sampling bag (FEP)
Our Teflon gas sampling bags are made of Fluropolymer (FEP) film and are highly inert for storage of gas samples. FEP film is the most chemically resistant film in the fluoropolymer family with low adsorption. The thickness of the FEP Teflon film is about 0,07 mm. These Teflon bags are very suitable for sampling at extreme temperatures ranging from ca. -205 degrees Celsius to +205 degrees Ceclius allowing these bags to be used under a wide range of conditions.
Applications of Teflon bags
The Teflon FEP gas sampling bags are suitable for high accuracy PPM and PPB analysis sampling, it can collect and save all kinds of strong corrosive and high chemical activity of gaseous, liquid samples and VOCs samples. Our FEP gas sampling bags are available with different valves and fittings and can meet a wide range of applications in environmental protection industry. Our standard Teflon bag comes with a single PTFE valve that combines the valve and septum into one. If you want to order Teflon bags with other fittings such as polypropylene please contact us.
Features of the FEP bags
- Teflon gas sampling bags have very low permeation of gases through the wall of the bags
- Superb resistance to chemicals, strong acid, strong alkali, strong corrosion and organic solvent, low adsorbability.
- Water vapor osmotic quantity is 1.3g/m2.24h.0.1Mpa, oxygen osmotic quantity is 2400cc/m2.24h.0.1Mpa (the data is the measured value, not the guarantee values
- Our standard Teflon bag comes with a single PTFE valve that combines the valve and septum into one
Information PTFE fitting
Regarding the fitting on the Teflon bags, the fitting is made of polytetrafluoroethylene (PTFE). The patented design utilizes moulding, self-sealing mechanism, no O-ring is inside therefore cross-contamination is eliminated. The connector of PTFE valve is vertical to the bag film, external diameter is 6 mm. When the handle is endways, the valve is open, when the handle is sideways, the valve is closed. The PTFE switch is easy to handle and swift and sealing tightly. It is suitable for filling of inorganic and organic gases which are not corrosive to PTFE. The sample cap has a silicone septum that can be used for needle sampling and it can be used in analysis high accuracy low concentration gas samples collection and preservation.
Instructions for use
- Inflation pressure: Avoid filling pressure higher than 6000Pa. Fill gas until the bag is full (approx. 90% capacity). Please make sure that you don’t fill the bag too much and the tension of the bag is too high, over-pressure may cause that the gas sampling bag bursts.
- Operating temperature: Working temperatures should be -60°C to +150°C for PTFE connector
- Storage and use: Keep away from flame and high temperature when filling and storage.
- Gas exchanging: Before use, flush sampling bags three times with the gas you want to fill.
- Needle sampling: When using a needle to draw gas from highly elastic septum, squeeze the septum with fingers in order to restore the sealing property after pulling out the needle.
Custom made Teflon gas sampling bags
Are you looking for sample bags with other sizes and specifications than our regular Teflon gas sampling bags? No problem, we are able to produce custom made sample bags based on your requirements. If you would like to receive a quotation for our custom made Teflon bags please provide us with the following information:
- Which foil do you need? Tedlar, Kynar® PVDF, Teflon®, Multi-Foil or Nalophan
- What are the required inside dimensions of the bag
- Which type of fitting do you require? Polypropylene, PTFE or stainless steel
- How many bags do you need?
- Does the bag need eyelets? If so, how many?
- Do you have a drawing or picture of the bag? If so, please send it with your request
Precautions Teflon bags
- Please note that the stability of the samples in the bags is limited. Specific saving time depends on multiple factors such as detection limit of experimental analysis requirement, gas component species, temperature and humidity, pressure, etc: generally, for pure inert gas, sampling bag can be used as a temporary storage container and recommended storage time less than 72 hours; for standard gas, flue gas, ambient atmosphere, recommended storage time less than 24 hours.
- We do not recommend reusing air sample bags in most cases.
- The gas sampling bag should be cleaned repeatedly before it is reused. If you are reusing the bag we recommend to collect samples of the same kind of gas, don’t mix.
- High purity nitrogen gas heating replacement can reduce the interference of organic deposition.
- When sampling and cleaning, please do not exceed 80% of the calibration volume, take 1L sampling bag for example, suggest sampling volume is less than 0.8 L.
- There must be a blank sample compare for precise experimental analysis to do background deduction.
- For high-temperature high-pressure gas should be down to normal temperature and pressure to sample, specific treatment method according to actual situation
- For negative pressure gas, should be sampled by appropriate power and flow rate vacuum pump.
- For the gas containing particulate matter, dust and aerosols, should adopt filter to prevent polluting the sample bag, then difficult to clean.