Corrosive and Dangerous Gas Policy

Updated: July 16, 2025

This Corrosive and Dangerous Gas Policy is applicable for models: d·flux, SmartTrak 50, SmartTrak 100 Series, and TopTrak 820 Series flow meters and controllers.

This policy is intended to offer specific information regarding the service and warranty of Sierra’s d·flux, 50, 100, and 800 Series flow meters and controllers in applications where the gas to be used can corrode stainless steel.  This most often occurs with gases that, in the presence of air, become powerful acids. Usually, the result of removing an instrument from a proper installation. It is rarely the result of “wet” gas at your location or improper handling, though this is always a concern.  Instead, it is because of the difficulty encountered in completely purging the reactive gas from the instrument. When such a device is returned to our facility (where humidity is always present), it becomes exposed to moisture. This begins the corrosion process. The simple nature of removing such an instrument and returning it to us can damage the device.
 

Return Policy Concerning Scientific Units Exposed to Corrosive and/or Dangerous  Gases

Sierra’s d·flux, 50, 100, and 800 Series flow meters and controllers are compatible with most gases due to their 316 stainless steel flow bodies and sensors, provided they are used with the recommended elastomeric seal material. However, these gases can often mix with other gases or liquids during use which can alter their chemical properties and create a corrosive or dangerous condition, as noted above.

Because of safety concerns, Sierra has adopted a “Do Not Return” policy for meters and controllers subjected to the following gases: 

 
Gas Name  Gas Symbol
Boron Trichloride
BCl3
Chlorine
CL2
           Ethylene Oxide            C2H4O
Fluorine
F2
Hydrogen Chloride
HCl
Hydrogen Fluoride
HF
Hydrogen Sulfide 
H2S
Nitrogen Dioxide
NO2
           Tetraethyl Orthosilicate            Teos
Tungsten Hexafluoride
WF6
Sulfur Dioxide
SO2
Uranium Hexafluoride
UF6

Sierra Policy Summary

  1. Other gases that are not listed might also be considered corrosive or dangerous. Before attempting to return a device to the Sierra factory for service, please provide Technical Support with a Material Safety Data Sheet (MSDS) for approval before attempting to ship.
  2. Devices subjected to listed or non-approved gases are NOT to be returned to the Sierra factory for service or calibration, regardless of purging or cleaning.
  3. The normal 1-year warranty is void once the device is exposed to one of these gases.
  4. If a problem arises, contact Sierra Technical Support for a possible solution, or to order a replacement at a discount. Standard lead times apply.
  5. If a device has been calibrated for one of the above gases but has not yet been exposed to it, it may be returned for service. A signed Non-Exposure Statement must accompany the shipment. This document is provided on the Sierra Instruments website during the RMA process. If there is any question, please contact Sierra Technical Support during Pacific Time business hours. 
  6. Hazardous Gas Policy: An Ammonia device or a device using a hazardous gas on the list below may be returned for service through the RMA process, but you must complete the “Declaration of Decontamination Policy and properly purge your units before returning to Sierra.

    Note: The list of gases that require a “Declaration of Decontamination” form can change. Please check our Dangerous and Corrosive Gas Policy web page for the most current list.
     
Hazardous Gas List
Ammonia Germane Phosphorous Pentafluoride
Arsine Germanium Tetrachloride Phosphorous Trichloride
Boron Trifluoride Hydrogen Bromide Silicon Tetrachloride
Boron Tribromide Hydrogen Cyanide Silicon Tetrafluoride
Bromine Hydrogen Iodide Tetrafluorahydrazine
Bromine Pentafluoride Hydrogen Selenide Trichlorisilane
Bromine Trifluoride Iodine Pentafluoride Trisobutyl Aluminum
Carbon Monoxide Methanol Titanium Tetrachloride
Carbon Tetrachloride Methyl Bromide Trimethylamine
Carbonyl Fluoride Methyl Mercaptan  
Carbonyl Sulfide Methyl Trichlorosilane  
Chlorine Trifluoride Molybdenum Hexafluoride  
Chloroform Monoethylamine  
Cyanogen Monomethylamine  
Cyanogen Chloride Nitric Oxide  
Diborane Nitrosyl Chloride  
Dichloromethylsilane Perchloryl Fluoride  
Dichlorosilane Phosgene  
Dimethylamine Phosphine  
Ethanol Phosphorous Oxychloride  
 
 
 

Sierra Industrial Device Policy Summary

Industrial products such as 620, 640, 780, 240 and 241, if exposed to any of these gases, must be properly cleaned and purged in order to return for service. During the RMA process, a “Declaration of Decontamination” must be completed and signed, and an MSDS document supplied with the shipment.

Download PDF of Dangerous and Corrosive Gas Policy