2 PSI Gas Systems

Every year 2 PSI gas systems become more and more popular. I have seen an increase in 2 PSI regulators sales over the past four years and I believe that this is due to the additional BTU loads that are the result of more people converting from a Conventional Tank water heater to a Tankless water heater. While a Conventional water heater has an average BTU load of about 40,000 and a residential Tankless water heater has an average BTU load of about 175,000, the Tankless is a lot more efficient.

When a customer changes from a conventional water heater to a tankless water heater the original gas line that was designed for the conventional system will more than likely not be sufficient in size to handle the new tankless BTU load.  In this case there are only two ways of fixing the problem to make the gas piping sufficient:

1. Remove the existing piping and start over with a larger gas piping system designed to meet the footage and BTU load. However, this is very time consuming and is very expensive for the customer. It could keep the customer from going forward with the conversion or maybe go a totally different direction such as adding an electric appliance.
2. Leave the existing piping and make it a 2 PSI system. You will still have to calculate all the BTU’s and the existing pipe that the customer has, but more than likely it will be sufficient after adding the 2 PSI regulators and the line pressure regulators. It is a simple fix and not as expensive for the customer because there is a lot less labor involved. The main thing is you do not have to wonder if you have enough gas volume to run the gas appliances.

Here are a few choices when considering installing a 2 PSI system.

• Two Stage 2 PSI System – 10 PSI regulator (LV4403TR9) at the tank and a 2^nd stage 2PSI regulator (LV4403Y4) at the building. Once inside you will have to install the 2PSI to the 11’’ WC line pressure regulators to go to the appliances.
• Twin Stage 2PSI System – Regulator (LV404Y9) goes on the tank and reduces gas pressure from Tank Pressure to 2 PSI. From here you would have to run a line pressure regulator in the house to reduce pressure from 2 PSI to 11’’ WC for each of the appliances.

These are just a few options when your customer is considering adding an additional BTU load to their existing gas piping. Always follow your line sizing charts set forth and in accordance with NFPA 54 and your authority having jurisdiction.

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