Analog Water Meter

An Analog Water Meter is a very common device found in homes, apartments, condominiums, and other domiciles that are installed on a residence's main water feed. Analog water meters, once installed, "meter," or "measure" the amount of water that is entering the residence. This amount of water entering the residence is termed the "usage" that the home has consumed. This usage can be measured in any number of ways, but the 2 most common units of measurement are "cubic feet of water" or "gallons of water."

While their technology is quite old and their composition is quite simple, analog water meters are in use all over the world to accurately measure water consumption and will still be in use well into the 22nd century.

Purpose

Analog water meters measure the amount of water that passes through them in "units." Units are displayed on the top of the meter in whole units and tenths of units. Depending on the manufacturer, these numbers can be any color, but are mostly black and white.

Intentions

Analog water meters can be installed on a residence for any number of reasons:

• to see if the home has a leaking water pipe
• to gauge how much a set of residents use water
• to test the accuracy of the meter itself

However, the main intention is to capture the usage of water in order to ascertain an amount of money to be charged the residence owner. This charge can be done in several ways, but usually is in the form of a monthly utility bill.

Charges

Charges can be established by multiplying a set cost per unit of water by the total used amount of units consumed. These units are usually gallons or cubic feet, but the cost depends upon the municipality or water company that the home owner is using. Other factors include:

• Existing infrastructure
• Processing (purification and chemicals used)
• Repairs
• Updating and upgrading an existing system

Example of a Water Charge

An existing municipality bills its residents $10.00 per unit of water usage. They also charge a fixed fee for infrastructure and processing. The home owner's water meter shows that over the course of the month, they have used 8.7 units of water. The resident's monthly bill should reflect:

WATER USAGE: $10.00 x 8.7 units = $87.00

WATER FIXED MONTHLY: $3.20

TOTAL: $90.20

$90.20 would be the resident's monthly water charge.

Composition

Analog water meters consist of a "bell" and a "globe." The bell of the water meter, especially older models, is made of brass and contains the "guts" of the meter. The bottom of the bell is secured with a "frost plate" (also known as a freeze plate). The globe of the meter is usually a plastic casing that holds the gears for the analog read-out. The top of the globe is transparent plastic and shows the analog read-out, the water movement indicator, and the rate at which the water is passing through the meter.

The Bell

The bell is a brass, pot shaped device with 2 fittings for water. Within the interior pot shape, a plastic cylinder called "the guts" or "the puck" is seated. This puck is plastic and contains the spiral blades of a fan. These fan blades move in the direction of the flow of water as water moves through the bell of the meter. Each revolution of the fan blades cause a magnet located at the top of the puck to spin. This spinning magnet causes another magnet in the globe of the meter to spin as well. The magnet inside of the globe then turns the gears that move the water usage indicator dial as well as the analog water usage read-out at the top of the meter.

The puck is held in place by a U-clip that is usually made out of plastic. Plastic screens are also placed at the inflow and outflow orifices of the meter to protect the guts from minerals and other chemicals from damaging the interior of the meter. These screens are usually curved to fit the interior of the pot or are cylindrical and fit into the inflow and outflow orifices.

The Puck

The puck, or the "guts" of the analog water meter consists of a plastic shell that contains an axle that holds fan blades. Water passing through the puck will move the blades and spin a magnet located at the top of the assembly. Additionally, the puck is held in place with U-clip and then sealed into the bell of the meter with an O-ring and a seal that is commonly called a "bladder."

The Frost Plate

At the bottom of the pot, a frost plate is installed with 1/2 inch bolts. The frost plate, made of a cheap iron alloy, is used as a safety feature to protect the meter. It's construction is such that the alloy of the frost plate is softer and will break away when water freezes and expands inside of the brass pot. Almost all damage that occurs to analog water meters happens during the winter and is a broken frost plate.

The Globe

The globe of an analog water meter is a clear plastic housing that contains the gears which move all of the indicators located at the top of the meter. These gears, propelled by water movement, are inside of a sealed plastic sheathing on the top half of the meter and a copper (sometimes plastic) cap at the bottom of the meter.

On most the common meters, the globe is affixed to the bell of the meter with a hardened plastic protection band that is closed tight with security screws that can only be removed with special tools. Other meters can have a "screw type" mechanism that affixes the globe to the bell. Screw type meters also have security screws requiring special tools to take the assembly apart.

Damage and Repair

Most water meters in use are rebuilt from older parts. A single, brand new analog water meter can be quite expensive so repair kits, rebuild kits, frost plates, and other parts can be obtained to fix a meter that is not working.

Malfunctions

Almost all problems that occur with analog water meters are user error. The following items are common reasons why an analog water meter will malfunction:

• installed backwards - this will lead to the meter not registering any usage.
• installed without the rubber washers - this will lead to water leaking.
• frost plate bolts cross threaded - this will lead to water leaking and not registering usage.
• allowed to freeze - this will lead to water leaking, not registering usage, and potentially destroying the meter.
• become clogged due to high mineral content in the water - this will lead to the meter not registering any usage.
• inflow and outflow connections cross threaded - this will lead to the meter not registering any usage.

Damage

While most problems with analog water meters are due to user error, over time a water meter can become less effective because of wear and tear. Analog water meters that are allowed to freeze, thaw, and then refreeze will have pitting and an occurrence where the brass metal of the pot will become "stretched." This stretching will bend or make the pot crooked. Once this bending happens, the pot of the meter is no longer usable and must be replaced. Deformed pot parts should be recycled or returned to the manufacturer for refitting.

Globe parts that become exposed to the elements can also fail. Being buried underground, submerged in water, or exposed to high heat can cause the gears inside the globe to freeze and stick in place, rendering the water meter useless.

The frost plate is designed to break in case water freezes inside of the meter. However, a meter that is installed correctly and protected from the cold should go decades without any damage to the frost plate. If water freezes inside of the pot, the expanding water will break the frost plate, bend the frost plate bolts that hold it in place, and can potentially rip the brass of the pot itself.

Rebuilding

Because analog water meters are prone to damage, rebuilding them can become necessary. Rebuild kits are usually available from the meter's manufacturer or through the distribution company that the meter was originally bought from. It is considered "best practice" to repair a meter with parts from that meter's manufacturer. Using other manufacturer parts can result in a non-working meter or a meter that provides the wrong usage read out.

Common Issues and Repair Solutions

• Frost plate is broken - Replace with new frost plate. Check to see if the bolts are bent. If so, replace those as well. Both of these parts should be salvaged from meters that have not sustained frost plate or plate bolt damage.
• O-ring or Bladder is cracked and leaking - Replace with new O-ring or Bladder. Both parts are available in a rebuild kit. Any older meters should be salvaged of these parts and saved for other repairs.
• Globe becomes cloudy - If heat or age may make the clear plastic read-out area of the globe unreadable, cleaning with a very soft abrasive is required. Soft Scrub or a cheap toothpaste is recommended.
• Meter stops reading usage - Check the guts inside of the pot. If damaged, replace the guts with a new set. If the guts are still in working order, this means that something else is impeding the flow of water with in the pot. Minerals can build up over time and are usually the cause of this issue. Check the screens in the in-flow and out-flow orifices. If they are clogged, clean them. Stubborn Calcium deposits can be soaked in vinegar to dissolve them.
• The pot has pitting on the surface where the frost plate attaches - This happens when a meter is allowed to freeze and thaw several times or from meters that are quite old. Pot surfaces can be "refaced" with the use of a bench grinder and then cleaned up with a steel brush. Repeatedly damaged pots must be replaced.
• The pot brass has ripped or warped - This also happens when a meter is allowed to freeze and thaw several times. Replace the pot with a new pot constructed by the original manufacturer.
• Bonnet connections are leaking - The rubber washers that come with the bonnet are not installed, installed incorrectly, or have become damaged. Remove the bonnet and check to see if there is a rubber washer within it. If not, install a new one. If the washer is damaged, replace with a new one.
• Bonnet connections are leaking - Meter bonnets can also be cross threaded, meaning the connection with the pipe is not correct. Additionally, an installer may have used pipe thread rather than the O-ring that comes with the bonnet. Pipe thread will not make a sealed connection in a meter bonnet and will leak. Remove the pipe thread with a steel brush and replace with a rubber O-ring.
• The meter is leaking at the frost plate, but the frost plate is not broken - Check the frost plate bolts to see if they are bent. A bent bolt will not "seat" the frost plate to the meter pot correctly. If bent bolts are found, replace with new bolts.
• The meter is leaking at the frost plate, but the frost plate is not broken and the bolts are straight - Check the O-ring, U-clip, and bladder inside of the meter pot. If any of them are installed incorrectly, or damaged, the meter will leak.
• The globe has become detached from the pot of the meter - Re-attach with a new security band and security screws. If it is a newer "screw top" meter, it was not seated correctly and needs to be removed and screwed back on the meter in the correct manner.

Installation

As mentioned above, analog water meters must be installed correctly to work correctly. A meter must also have protection from outside elements as they are usually installed outside of the home or in a portion of the home that is not directly heated.

The Meter

On the meter's inflow orifice, there are 2 items embossed upon the brass. The first is a number that represents the outside diameter of the pipe that mus be fitted to the inflow's threads. The second item is an arrow that shows which direction the flow of water must go as it travels through the brass pot of the meter. Usually, this means that the arrow must point towards the home or residence that the meter will be attached to.

Connections

Analog water meters are connected to both the source water main and the home's water pipes by two "bonnets." These bonnets are brass fixtures that resemble a brass pipe that has an unattached collar of brass that is threaded. One end of the bonnet pipe is male threaded so that it can be connected to the water main or to the home. The brass collar is not affixed to the brass pipe. It has a female threaded interior that also is used to keep and hold a rubber O-ring.

After the water main source pipe is found, the installer must then figure out what sized union to use to connect the inflow side bonnet. Once the correct fittings are installed, the male end of the inflow side bonnet must be connected to the water main. When doing this, the installer must use Teflon thread tape or pipe dope to prevent leaks. To attach bonnet to the meter, the female inflow end screws onto the meter pot inflow. This pot inflow is threaded and the installer can use "hand tightness" to put the female portion of the bonnet onto the meter. Be sure to have the rubber O-ring inside of the female portion of the bonnet and that it is seated correctly.

Repeat the process on the other side of the meter. Again, take care to have thread tape and O-rings installed before you tighten down both sides with a pipe wrench.

Protecting the Meter

After installation, the meter must be protected. An analog water meter is best protected when it is insulated; both on the connecting fixtures and the meter itself. For added protection, the meter should be off the ground and supported. Do not support the meter with it's pipes; they should have their own strapping to take strain off of the pipes that are connected to it.