Linc Energy Blog

Having sold gas measurement equipment for decades, I’m often asked, “What is a turndown ratio?" While turndown (turn down) ratio is usually noted in a flow meters specifications, it’s rarely explained in layperson’s language what it actually is.

Turndown ratio is also commonly referred to as rangeability. It indicates the range of flow a meter can accurately measure the natural gas (or whatever is being monitored). In other words, it’s simply the high end of a measurement range compared to the low end, expressed in a ratio and is calculated using a simple formula.

Turndown Ratio = maximum flow / minimum flow

To put this in perspective, if a gas flow is expected to run between 350,000 cubic feet/ day and 3,500,000 cubic feet/day the application would have a turndown ratio of 10:1. Turndown is one of the key parameters used to select the proper flow meter technology for a specific application. Other factors which help select the right flowmeter are: the product being measured, its flow, the price of the equipment, maintenance cost and accuracy.

The chart below includes turndown of various flow technologies.
 

The Sage Metering thermal gas mass meter has a wide turndown of 100:1 (with 1000:1 possible upon request) which is extremely desirable for natural gas applications because of the large swings in demand throughout the course of a day as well as seasonal fluctuations.

What is turndown ratio? One of the first parameters to consider when ascertaining which flow technology to use for your natural gas application.  For more information read "What is a thermal mass flow meter?"

* Please note that these figures are a guideline and referenced on https://controls.engin.umich.edu/wiki/index.php/FlowSensors#Thermal_Flow_meters. They may be different from manufacturer to manufacturer.
 

Tags: natural gas industry, back to basics, thermal mass flow meter, natural gas measurement

As a stocking distributor of natural gas regulators, I’m often approached by customers seeking alternatives to a specific competitor's natural gas regulators. While there are other manufacturers, there seem to be five which are noteworthy to cross reference.

• Itron (formerly Actaris, Schlumberger and Sprague)
• Fisher (Emerson Process Management)
• Sensus (formerly Invensus, Equimeter and Rockwell)
• Elster American Meter
• Maxitrol
   

For your convenience, here is a competitive comparison chart or a selection guide to help cross reference the major regulator manufacturers.  Remember this is only a reference and feel free to call me if you have questions. 303 - 697 -6701.
 

To learn more about regulators, consider reviewing:

• How to select the correct gas pressure regulator?
• Why are regulators used in natural gas distribution?

 

 

Tags: regulators, back to basics

Continuing my "Back to Basic" series, I thought I'd address sizing natural gas regulators.

As a stocking distributor of natural gas regulators, I’m often asked by my customers which regulator to use for a particular application. I usually ask a few questions and am able to quickly direct the customer to a product. Occasionally a DIY-type (do-it-yourself) will ask, “What’s the secret to selecting the correct product?”

There’s no secret, and I’m happy to share the information which is why I’m posting it here. There are five areas which help me ascertain which regulator to recommend:

• What type of gas are you regulating? While the majority of my customers are inquiring about natural gas, or methane, I can assist in the regulation of other fuel gases.
• What is the inlet pressure? If you don’t have a pressure gauge, you can always call your gas distributor, or inquire about some of the fine gauges (gages) we have available.
• What is the desired outlet pressure?
• What is the flow? 
• What is the desired pipe size?

If you have the answers to these questions, you have the information needed to select the correct regulator. Without a background and knowledge of regulator capabilities however, you may find yourself studying endless sizing charts and graphs. This download will give you an idea what a sizing chart looks like.

While there are some sizing programs available, they’re not foolproof and until they are, I personally still size my customer’s regulators the old-fashioned way.

Before you get the magnifying glass out to pore through those charts, remember I am happy to assist my customers by sizing regulators for their applications.

 

photo: Itron
 

Tags: regulators, back to basics

In this back to basics entry, I discuss why natural gas pressure regulators are used in a delivery system.

After natural gas makes its way out of the well, into gathering and transmission systems, and gate stations, it ultimately enters distribution lines (or “mains”).

B31 residential regulator

While gas is in the distribution system, regulators control the flow from higher pressure to lower pressure. Regulators sense if the pressure in a line drops below a specified set point and opens, allowing more gas to flow. On the other hand, if pressure rises above a set point the regulator will close so that the downstream pressure adjusts.

When natural gas leaves the main, it travels through a “service line” to reach homes or businesses. This service line is likely to be polyethylene, perhaps an inch or less in diameter and ranges from about 60 PSI to ¼ PSI. Once the gas reaches the home or business meter it passes through another regulator to reduced the pressure under ¼ PSI and is measured in water column.

Throughout the gas delivery system, from the well to the stove burner, regulators are used to adjust the pressure to ensure safety.
 

Tags: back to basics, natural gas, regulators, transmission, gathering