An expansion tank is a small tank that is used in closed water heater systems as well as domestic hot water units. The tank is designed to take in the excess water pressure that may be cause by the thermal expansion or more commonly called water hammer. The expansion tank is a small or mid size tank that is made with 2 separate sections. One side of the tank will be used for excess water and the other side is the dry side that will hold the air pressure. Expansion Tank Buyers Guide

Every system has one and there may come a time when you are going to need to replace that system. There are so many brands out there but there are just a handful of companies that will offer you reliable, durable and efficient products. As a homeowner you may not know what to look for or as a professional you may be looking to comparison shop for a new brand. So we have compiled a list of Expansion Tanks to help you make an informed decision on which tanks have the features and specifications you are looking for.

Watts PLT-12 Potable Water Expansion Tank

Watts is a great company with a well-matched reputation. All of their products are efficient, compact and reliable. Watts products have great warranties and the company stands behind every product they make. The Watts PLT-12 comes with a 3/4″ male connection and a tank that hold about 4-1/2 gallons of water. The PLT Series of Expansion Tanks can be used on most heating systems such as gas, oil, electric or direct fired. Watts caters to both the professional and the residential fields. This residential water expansion tank is designed to help take in the excess volume of water that is created by thermal expansion from the system. The PLT Series can hold up against pressure that occurs throughout the water supply system. This is done by maintaining the system’s pressure by keeping below the proper T&P relief valve setting.

The Watts PLT-12 Potable Water Expansion Tank is a pre-pressurized adjustable; steel tank that is made with a polypropylene liner and a Butyl rubber diaphragm. The maximum water temperature is 160 degrees Fahrenheit with a size range of 3/4″. The Watts PLT-12 Expansion Tank’s membrane is designed to stop air to water coming to together in the tank. The strong the membrane the long life the expansion tank will be. The cost for the Watts Expansion Tank PLT-12 is about $65.00, if you shop around you could find a better deal.

Amtrol FILL-TROL 109

Amtrol has been in business for many years, they have a great reputation as well as Watts. The Amtrol FILL-TROL 109 is pre-charged at the factory and they are thoroughly tested before being shipped out. The FILL-TROL 109 system comes with a special adapted EXTROL pre pressurized expansion tank that comes set at 12 psi. All of the tanks are made from a sturdy and reliable welded steel construction. This system can be used with hot water heaters, glycol systems and heating systems. The FILL TROL 109 comes with an automatic pressure-reducing valve.

The tank is fully adjustable up to 100 psig working pressure and the company recommends installing an EXTROL into the bottom of the tank by using a 1/2″  inch nipple for the pipe and mounting connections. This style of tank is called a bladder tank. The tank’s job is to control the high and pressure made by the water expansion. The bladder tank has a moving bladder and will need a separate pressure reducing valve or a FILL TROL to keep up with the pressure of about 12 psi. The maximum temperature of the Amtrol FILL TROL 109 is about 240 degrees Fahrenheit. The maximum water pressure is 100 psi. The tank can hold about 2 gallons of water and will accept a maximum volume of .9 gallons. This tank is a lightweight tank, weighing in about 6 pounds. The price of this 2-gallon expansion tank is about $ 84.00, but if you shop around you may find a little bit of a better price.

Caleffi Solar Expansion Tank

The Solar movement is becoming more popular in recent years. They have solar panels for heating, solar panels of heating of swimming pools and now solar expansion tanks. This is onsidered to be a modern version of the solar heating system. This expansion tank can withstand temperatures of 385 degrees Fahrenheit while the tank is not being used. What happens with a solar expansion tank is that liquid vaporizes and the high temperatures in the solar circuit go to the solar stations. The pressure of the diaphragm promises that the system pressure will not exceed or fall lower than the system is designed for. The Caleffi Solar Expansion Tank comes with a welded steel body that is coated with an epoxy paint to ward off corrosion. It comes with a temperature system range of 15 degrees Fahrenheit to 250 degrees Fahrenheit. It has a maximum diaphragm temperature of 210 degrees. The working pressure allowed on the Caleffi Solar Expansion Tank is 150 psi with a factory pre-charge of 35 psi.

There are 2 different size tanks available, a 3-gallon tank and a 5-gallon tank. As the volume in the tank expands the diaphragm will stretch into the gas chamber. When this happens the space that was available for the solar fluid will increase and the pressure inside will stay the same. The price ranges on the Caleffi Solar Expansion Tanks from $58.75 to $159.75.

N-30 Wessels # 30 Expansion Tank

The Wessels N- Style Expansion Tank are non-ASME diaphragm types of tanks. They are factory pre-charged tanks that are designed for important protection of hydronic heating systems. These tanks are created for installation that will be able to take in expanded hot boiler water. At the same time, keeping the systems pressure well below the relief valve settings. The tank is a steel water reverse with a double clamped diaphragm that separates the water and the air cushion. With the design and the way this tank works it will provide a smaller tank size of about 80% than the others. The N-30 Wessels #30 Expansion Tank can hold about 2.1 gallons of water and has a system connection of about 1/2″. The tank can hold about 240 degrees Fahrenheit with a maximum working pressure of 150 psi and the tank is pre-charged with 12 PSI but a technician can adjust them.

The N-30 Wessels #30 Expansion Tank is more compact than the other expansion tanks on the market. Due to their smaller size the cost of these tanks are less than the others, the N-30 Wessels cost about $30.00. The expansion tank is needed for all hot water boiler systems. The concept of the expansion tank is to control the pressure and reduce the amount of energy being used on the heating and circulating systems. These tanks are necessary to the water heating system to hold the excess water and pressure that builds up. Without these tanks the hot water system will not run properly. These tanks are necessary and there are times when the tanks have to be replaced.

All of these tanks we profiled are cost effective and reasonably priced. Buying an expansion tank can be very confusing and very frustrating but with this buyers guide we hope to make your choice a bit easier. All of these companies that we profiled have many years in the industry and any one of these expansion tanks will make a great addition to your hot water heating system.