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Gas Regulators



Select the Proper Regulator

Installing and Using a Regulator

  1. Make sure your cylinder is properly secured, that you have the correct regulator and that you are aware of any special hazards of the gas you are working with.

  2. Remove the cylinder valve cap (counterclockwise). Place it somewhere nearby.

  3. Some regulators (on lecture bottles and certain corrosive gases) require a Teflon or lead washer to be inserted between the tank outlet and regulator. Check to see if this is required before continuing.

  4. Make sure that the regulator outlet valve (A) is shut. Screw it clockwise until it seats. Do not overtighten it or you can damage the valve seat.

    a gas regulator

  5. Make sure that the regulator control valve (B) is shut. Screw it counterclockwise until it is almost completely unscrewed. If you unscrew it completely, just put it back in.

  6. Screw the regulator onto the tank by hand until it is almost finger tight. Some people like to use Teflon tape on this connection, but that's generally not a good idea. Bits of Teflon tape can get blown into the regulator, causing a leak, valve malfunction or erroneous reading.

  7. What you do next depends on the kind of gas you are working with and whether you need to exclude air from the gas line you're connecting to. Aldrich Chemical discusses this in more detail in their Technical Bulletin AL-151, Gas Equipment Configurations.

    For nitrogen and argon cylinders:

    For corrosive or reactive gases:

    For flammable gases:

  8. Open the tank valve slowly (counterclockwise). Watch the tank pressure on the regulator (C).

  9. Slowly turn the regulator control valve (B) until the regulator pressure (D) is at the desired level.

  10. Open the regulator outlet valve (A). You can regulate flow with this valve, but the ultimate pressure depends on the setting of the regulator control valve!

  11. Check your system for leaks using Snoop (a commercial product) or some soapy water. Snoop is preferred since it leaves no residue. If you find leaks and tightening the connections does not help ask your instructor for assistance.

    Reminder: Do not use Teflon tape on Swagelock ferrule compression fittings.

Disconnecting a Regulator

  1. Shut the tank valve on the gas cylinder.

  2. Slowly open the outlet valve (A) on the regulator .

  3. Watch the pressure gauges C and D drop to zero.

  4. Open the regulator control valve (B) (turn it clockwise) to ensure that all pressure has been released.

  5. If you were using a corrosive gas, purge the system with a dry inert gas.

  6. Using a wrench (not pliers!) disconnect the regulator from the gas cylinder. Replace the protective cylinder cap immediately.

  7. If your regulator was used with a corrosive gas, purge it again with dry air or nitrogen in the hood for several minutes.

  8. If your cylinder is empty, it must be properly labeled and then returned to the manufacturer or distributor (in many cases, this is your school or company stockroom). Do not store empty gas cylinders in the laboratory.

    Reminder: Make sure the tank valve is closed whenever you are not dispensing gas through the regulator.

Further Information

cover illustration
Handbook of
Compressed Gases

by Compressed Gas Association
& Debbie Angerman


This page was last updated Friday, October 22, 2010.
This document and associated figures are copyright 1996-2015 by Rob Toreki. Send comments, kudos and suggestions to us via email.