AIR MONI TORING
Canister Maintenance/Canister Recondi t ioning
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Phone: 800-356-1688 or 814-353-1300
How to Extend Canister Life
What reduces canister performance and longevity? Leakage is the most common reason for canister failure,
but contamination and damage to the fused silica lining can also send canisters to the scrap yard prema-
turely. Here are some tips to protect your investment:
1. Prevent leaks
Use proper handling to avoid these 3 leading causes of leaks.
a. Particles in the valve
You can prevent particles from entering the valve by always using a 2 or 7µm particulate filter during
sampling and on your canister cleaning equipment. Also, protect the valve inlet by replacing brass dust
cap when not in use. The EPA-recommended metal-to-metal sealing valves provide the greatest inert-
ness, but tend to be more sensitive to particulate damage than other valve types.
b. Galled thread fittings
Avoid galled thread fittings by using a gap gauge to prevent overtightening of compression fittings.
Turning only ¼ turn past finger-tight is another rule of thumb to prevent overtightening. Use brass
compression fittings on stainless steel, during nonsampling activities, such as cleaning or calibration,
to minimize thread damage. Galled threads may also cause a poor connection to vacuum/pressure
gauges, resulting in inaccurate measurement and misleading conclusion that canister leakage exists.
c. Overtightened valve
Canister valves are designed to close securely with hand tightening only. Overtightening a valve closure
with a wrench can damage the valve seat where the seal is made.
2. Reduce contamination
a. Segregate high concentration (ppm) cans and trace concentration (ppb) cans. Use dedicated canisters,
or gas sampling bags, for ppm level sampling, since it is extremely difficult to remove impurities
from ppm sampling to a level suitable for trace sampling.
b. Clean the entire sampling train as you would the can to minimize introduction of contaminants into
a clean can. Maximum temperature is 80°C on the gauge and 90°C on Restek’s Veriflo flow controller.
c. High temperature (>100°C) humidified air (steam cleaning) provides the most effective way to remove
contamination from electropolished cans (TO-Can™ or SUMMA® canisters), but can damage
fused silica lined cans. See #3 below for proper cleaning of fused silica lined cans.
3. Avoid damage to fused silica lined cans
Be sure to followmethod recommendations when cleaning your canisters to avoid damaging the fused sil-
ica lining. Cleaning studies of SilcoCan™ canisters using humidified air and heat at 80°C and 125°C have
shown reduced recoveries of sulfur compounds, when compared to using nitrogen under the same con-
ditions. This irreversible damage is due to oxidation of the surface, creating active sites that may affect
the recovery of reactive or polar compounds. Strong acids and bases may also result in damage to the
internal can surface.
Reconditioning Service for SilcoCan™ or TO-Can™ Canisters
Normal wear and tear on a canister may result in valve damage and leakage. We offer a reconditioning
service in which we will replace the valve, clean, and leak test the canister for much less than the cost to
replace the entire canister. If you would like this service, please follow the instructions below:
1. Contact Customer Service at 800-356-1688, ext. 3, or contact your Restek representative and place an
order for part number 560838 using your company purchase order.
2. Obtain a return authorization number to affix on the outside of the shipping container.
3. Clean canister before shipment to Restek.
4. Return canister intact. Do not remove valves or gauges that were part of the original canister.
Neil Mosesman
Marketing Manager
20+ years of service!
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Website ;
Email :
Tel No : 03 9762 2034 in AUSTRALIA
