# How To Weigh A Gas Cylinder

Liquified gas cylinders are ubiquitous throughout industry. Some of the more common types include carbon dioxide, chlorine, ammonia, liquified propane gas, also known as lpg, nitrous oxide, and many, many others. The most common size cylinder used is about 9” in diameter, and can be about 45” in height.

There are specific industries that use, and therefore need to weigh liquified gas cylinders by weighing it on a scale. They include petrochemicals, pharmaceuticals, chemicals, and electronics. The semiconductor fabrication industry uses a number of liquified gases for processing silicon wafers into microprocessor chips and other integrated circuits.

## Calculating Gross Weight

The weight of the empty gas cylinder, plus the weight of the contents, is known as the total weight, or gross weight. The weight of just the contents, that is the liquified gas itself, is known as the net weight. Subtracting the net weight from the gross weight will provide the cylinder weight, which is the weight of just the empty cylinder, also known as the tare weight.

### Full Gas Cylinder Weight

To determine how much a tank weighs, it can be weighed on a Cylinder Scale. The capacity of the scale will be determined by the maximum filled weight of the cylinder. The size of the scale platform will be dependent on the size of the cylinders being weighed.

Full weights of the most common cylinders are about 245 lb. Some heavier units range up to 315 lb. A popular propane tank, or lpg cylinder, can be 14.2 kg.

There are also a variety of cylinder diameters in common use, the most popular being abou 9”, as noted above. Other larger sizes include 12” and 14”. Even larger cylinders would usually be weighed on a platform scale instead of a cylinder scale.

### Tare Weight

The most important parameter to know is the amount of contents in the cylinder. This, of course, will determine how long a process can run before the cylinder needs to be replaced. In automatic operation, it can also determine the flow rate of the gas being used.

Tare weights of cylinders are often marked directly on the body or neck of the cylinder itself. This is very useful for determining the remaining weight in the cylinder. When the cylinder is weighed, and the target weight is subtracted, the result will be the weight of the material still in the cylinder.

### Gas Weight And Density

Although it is useful to know the weight of the liquified gas in the cylinder, the user really wants to know how much gas is left. This is dependent on the density of the liquified gas. The higher the density, the more end product still remains.

For example, the density of water is 997 kg per cubic meter. But the density of liquid oxygen is 1140 kg per cubic meter. Similarly, the density of liquified natural gas is only about 450 kg per cubic meter, being much less dense than water.

## Why Weighing Gas Cylinders Is Important

Knowing the contents of a cylinder is helpful for many reasons. The water capacity of a tank will determine the maximum amounts. But you may need to know the pounds of propane in a particular tank.

### Improves Regulation Of Flow Rates

Flow rate is the amount of material used for a specific amount of time. For example, it could be 100 grams per minute, or 10 kg per hour. Valves are often used to adjust this flow rate.

Arlyn’s scales can calculate the flow rate by continuously monitoring the weight. It calculates the change in weight on a regular basis. The user can choose the units of weight and time that are most suitable.

Often, very small changes of weight need to be determined. Arlyn’s ultra precision scales are ideal for that purpose because they can weigh amounts that are ten to twenty times smaller than regular scales. This allows the flow rate to be calculated in a much shorter amount of time.

### Prevents Overfilling Cylinders

Gas cylinders are rated for a specific pressure and amount of material. Exceeding these ratings can cause dangerous conditions. Scales should be used to ensure that there is not too much material in the cylinder during the filling process.

### Reduces Damage From Interrupted Gas Flow Rate

Certain industrial processes require continuous flow of gas. If the tank runs out, and the gas flow is interrupted, an entire batch can be ruined. Monitoring the weight of the tank will prevent this.

## Uses For Gas Cylinders

There are as many different uses for these cylinders as there are different industries.

### Propane Tanks

This is one of the most popular types of cylinders. It is used domestically for operating heating appliances. It is used industrially for numerous purposes.

### Medical Equipment

Medical environments can require various gases, such as oxygen, nitrous oxide and liquid nitrogen. Stainless steel scales are ideal for this. Remote monitoring software can track the usage.

### Storage Of Hazardous Gases

Some gases may be flammable or explosive. The storage areas used for these cylinders may fall under certain classified hazardous conditions. Only intrinsically safe scales should be used for weighing these tanks.

### Liquid Petroleum Gas (LPG) Cylinders

Small LPG cylinders are used internationally for cooking gas. Larger tanks operate different types of industrial processes. They are available from many different suppliers.

## Simply Weigh Your Gas Cylinders With Devices From Arlyn Scales

Whatever type of cylinder may need to be weighed, in whatever type of environment, Arlyn Scales can provide some excellent solutions. Their dedicated sales staff has years of experience. Take advantage of this by giving them a call.

## Corrosion Resistant Scales For Weighing Cylinders and Drums of Corrosive Materials

Starting at \$1099

Starting at \$599

Starting at \$699

Starting at \$799

Starting at \$799

Starting at \$649