Itron Natural Gas Regulator Sizing and Effects of Altitude
How does altitude affect gas regulator sizing? When sizing an Itron natural gas regulator, we need to consider are six factors needed to be considered to select the most suitable regulator for your application; including location to adjust for the effects of altitude.
Types of Regulators
- Appliance regulators control the gas pressure to an appliance
- Line gas regulators are located on a gas line between a service regulator and appliance regulator
- Service regulators reduce service line gas pressure to delivery pressure
- Pressure regulators reduce, control and maintain the pressure of a specific portion of a pipe system
Parameters Needed for Regulator Sizing
There six parameters that help size and recommend the most suitable regulator for various applications. These aspects are:
- Gas type
- Available Inlet gas pressure; measured in pounds per square inch gauge (PSIG), inches of water column (in. W.C.), or ounces (oz.). Keep in mind that 1 PSI = 16 oz. = 27.7 inches W.C.
- The desired or regulated outlet pressure; measured as above
- The capacity, flow rate or gas load is the end user’s requirement to be supplied; measured in SCFH, BTU or MBH. Where SCFH=standard cubic feet per hour, BTU=British Thermal Unit and MBH=1000 times BTU
- Desired pipe size
Universal Standards at Sea Level
- Natural gas: 1 CFH = 1000 Btu/hr
- Propane: 1 CFH = 2550 Btu/hr
- Butane: 1 CFH = 3200 Btu/hr
- SCFH – standard cubic feet per hour ï¬‚ow (at 14.4 psia — sea-level atmospheric pressure at 60F)
Altitude Effect in Gas Regulator
Atmospheric pressure reduces with altitude which is why we need to ascertain the regulator location; to determine elevation.
As we increase in elevation by 300 meters (approximately 1000 feet), there is an approximate 4% reduction in atmospheric pressure. Assuming that the elevation of the Colorado Front Range is about 1608 meters (5300 feet), it would mean that there is an approximate 21% reduction in pressure from a sea-level location.
At sea level, one CFH of natural gas is approximately 1000 BTU/hour. Along the Colorado Front Range, however, a cubic foot of natural gas is approximately 830 BTU.
In “How to select the correct gas pressure regulator?”, I revealed how we use our selection information and refer to sizing charts to select the appropriate regulator for our applications. Here, I introduce the Itron Regulator Sizing Program, with the caveat: this program works for applications at sea level, and the effects of altitude are not taken into consideration.
Example of Regulator Sizing
The following is the selection information we’ve gathered for an application we desire to have sized. Go to the regulator sizing program and enter the following information:
- Internal Relief Only
- Gas Type: Natural Gas
- Available Inlet gas pressure: 2PSIG – 5PSIG min-max
- Desired outlet pressure: 8” WC
- Capacity: 750 SCFH
- Pipe Size: 1” NPT inlet and outlet
By answering the following parameters, the program quickly selects two regulators for this application. If you do not receive a prompt email for your applications, check your spam mail.
If you are not at sea level, call your local Itron Gas Meters and Regulators Distributor, and they will assist you in sizing a regulator for your applications.