Unwanted impurities can lower your purity ratings, cause regulator failure and even explosions in the workplace. Here are five best practice tips to prevent unwanted impurities from entering your pure gas or gas mixture application.
1. Choose the correct materials of construction
When choosing a regulator, you must be aware of material compatibility in order to avoid the following 3 issues:
Poor Purity Ratings
If you choose a regulator and gas combination which is not compatible, the purity rating will be nullified. See: Purity Ratings- Key Facts For Specialty Gases and Gas Regulators for more information.
Your regulator may fail prematurely as many corrosive gases can attack and destroy components inside a regulator not suited to that particular mixture. Stainless steel is often used for corrosive applications, but even stainless is not always the answer. Materials such as Hastelloy, Monel or Viton may be used for particular corrosive applications.
Regulator failure can cause (toxic) gas leaks, explosions, or at least incorrect calibration of your instrumentation. Make sure the materials are correct for your application.
2. Use only one type of gas with each regulator
In most cases it is important to ensure your regulator sees only one type of gas over its service life. Residual gases will always exist inside a regulator until thoroughly purged/cleaned out. If the residual gases are incompatible with the new gas, they can react causing impurities, a reduction in regulator service life, or worse a dangerous situation (for example, a flammable gas introduced into a regulator with a residual of an oxidising gas can cause an explosion).
3. Use a purging system
When you first connect your regulator to a cylinder and every subsequent time you change a cylinder, impurities are introduced into the system in the form of ambient atmosphere sitting inside any open spaces. Once you flow gas through the regulator, these impurities travel through the regulator and the rest of your system. In order to prevent this, a purging system should be used. This allows the operator to completely purge any unwanted atmospheric impurities before they are spread through the system. Several different types of purging systems are available to manage different applications.
4. Replace your gas regulators
It is advisable to replace your gas regulators at regular intervals to ensure your system is always performing at its peak. In general, it is suggested a 5-year service life is a practical time frame for a gas regulator which is used properly and purged regularly. If the gas regulator is used with an aggressive media the regulator life would be reduced. For example, a gas regulator designed to work with pure ammonia or chlorine may last for only one or two years. On the other hand, a regulator used sporadically and only with an inert gas, like pure nitrogen, may last eight or even ten years.
5. System Design
The best way to avoid unwanted impurities is to ensure your entire system, starting from the gas inside a cylinder right up to the point of use, is designed properly. Ask experts in the field to advise you how to eliminate any mistakes in your gas regulator selection.