Cryogenic equipment is used to store cryogenic gases in a liquefied state such as nitrogen, oxygen, and argon. Such material is stored and transported in highly specialized trailers that keep them at extremely cold temperatures. If held at room temperature, cryogens would simply return to their gaseous state. To keep them in a liquefied state, the equipment holding them needs to work properly. Cryogenic liquids are considered hazardous material so safety is paramount. Here are 10 common sense things you should know when working with cryogenic equipment.

1. Always Wear Proper Safety Equipment

There are several safe practices when it comes to working with cryogenic equipment and the material it holds due to their extremely low temperature and high rates of conversions. The most basic safety precautions starts with wearing the proper personal protection equipment including face shields, gloves, long sleeves, and ear plugs.

2. Never Cut or Grind Next to a Painted Tank

Keeping cryogenic equipment in top condition is key to keeping those around it safe. This includes keeping it from rusting, which is why you should never cut or grind anything next to a painted tank. The hot metal will embed in the paint, ultimately ruining it, and later the spots will rust.

3. Never Use Carbon Steel Wire on Stainless Steel

Carbon steel and stainless steel do not mix. You should never use carbon steel wire brushes or wire wheels on stainless steel. You should also avoid using these tools on stainless steel if they were previously used on carbon steel:

• SS Wire Brush
• SS Wire Wheel
• Scotch-Brite Pad

4. A Pressure Relief Valve Should Always Be Installed Where Liquid Could Be Trapped

You must ensure a pressure relief valve is installed between any valves or check valves where liquid could be trapped. If there is no pressure relief valve installed, your equipment is not only not up to code, but also could cause a dangerous situation if enough pressure builds up.

5. Never Operate Cryogenic Equipment without Proper Training and Authorization

This one is simple. Do not operate cryogenic equipment you have not been trained on or authorized to use it. Without proper certification and education, you’re not only putting yourself in danger, but also those around you and those around the equipment.

6. Do Not Use a Fitting, Valve, or Hose that is Not Rated for the Operating Pressure and Temperature

The rating of certain equipment, i.e. fittings, valves, or hoses, is important to the proper use of specific mechanisms, especially when it comes to pressure and temperature. Cryogenic liquids stored at the wrong temperature could vaporize and rupture the equipment.

7. Grind Down All Sharp Corners on Fabricated Metal Objects

Any sharp corners should be ground down to a rounded shape. This is to keep the equipment safer for those working near it.

8. After Fully Opening a Gate or Globe Valve on Cryogenic Equipment, Close it a Fraction of a Turn

Fully opening the valve and closing it at a fraction of the turn will prevent the valve from freezing in the open position. This makes it easier for you to close it when it’s cold.

9. When Tightening a Leaking Packing Gland on a Valve, Tighten Only Enough to Stop the Leak

When a packing gland on a valve stem is leaking, tighten it only enough to stop the leak, and no more. Then verify that the valve can still turn normally.

10. When Installing Teflon Tape, Always Start Back One Thread From the End

When installing Teflon tape on pipe or fitting threads, always start back one thread from the end. This will ensure that no slivers from the Teflon tape are cut off when the piece is threaded into its mate, and no debris is created to clog something up downstream. There is generally no need to ever install more than two or three wraps of Teflon tape on any pipe or tubing threads.

Bonus Tip: Get Help from a Pro

At Lawson Cryogenic, these are just some of the things that are built into our mindset, and have become second nature to us. Having your equipment inspected, tested, and repaired by a professional goes a long way. With over 100 years of combined experience in the cryogenic industry, our expert team can handle anything from structural repairs to complete rehabs. Give us a call at (281) 942-1235 or contact us online.

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