Horizontal Expansion Vessel
Horizontal expansion vessels also used as pump bases in booster pump sets: 24 and 50 litre models, 10 bar pressure class.
Products (5)
- 24 L Horizontal Expansion Vessel, 1 inch Connection – $38.11
- Forza FRZ-YGT24 Horizontal Expansion Vessel, 24 L, 10 Bar – $56.00
- Kentaş 24 L Horizontal Expansion Vessel, 10 Bar – Request a quote
- Nema NEQ 50 L Horizontal Expansion Vessel, 10 Bar – Request a quote (out of stock)
- Nortek 24 L Horizontal Pressure Tank and Expansion Vessel, 10 Bar – $69.60
Brands: Forza · Kentaş · Nema · Nortek
What is a horizontal expansion vessel?
Horizontal expansion vessels are pressurised tanks with their long axis parallel to the ground and a pump mounting plate on top. In booster pump sets, the pump is mounted on top of the tank to form a single compact unit. This arrangement saves floor space and makes it easy to bring the pump, tank, pressure switch, and pressure gauge together with short connections. It is also one of the most commonly replaced parts in booster pump refurbishments.
Which capacity should I choose?
- 24 litres: Widely used in detached house, single-apartment, and small garden irrigation booster pumps.
- 50 litres: Allows the pump to cycle less frequently in multi-apartment buildings and high-usage applications.
- Larger capacities: For high flow rate pumps, the tank is selected so the pump does not exceed the permitted number of starts per hour.
The larger the tank, the less frequently the pump starts, which extends the life of the pump and its electrical components.
Installation and maintenance
The tank connection port is typically connected to the pump outlet, pressure switch, pressure gauge, and supply line via a five-way fitting. If the pump is to be mounted on the tank, the mounting plate dimensions and load capacity must be compatible with the pump. Rubber pads can be used to secure the tank to the floor and reduce vibration. The air pressure should be checked at least once a year with the water side drained; water coming from the valve stem indicates the membrane has ruptured. On tanks with a replaceable membrane, only the membrane needs to be replaced in this case.
Frequently asked questions
What do I need to know to replace the tank on my old booster pump?
Note the capacity, connection diameter, and whether the pump is mounted on top of the tank. If the mounting hole spacing differs, an adapter plate may be required.
Why does rust form inside the tank?
In diaphragm tanks, water contacts the membrane, not the metal body. If rust is visible inside the body, the membrane may have ruptured and water may have reached the metal part.
Can a horizontal tank be used upright?
It is recommended to use the tank in the orientation it was designed for. If an upright installation is required, vertical expansion vessels are a more appropriate choice.
Why does the connection diameter matter when selecting a tank?
The tank connection must match the five-way fitting and pump outlet. Different sizes can be joined with a reducer, but this additional connection point increases the risk of leaks.
Does the tank come with the pressure pre-set at the factory?
Tanks are supplied with a specified pre-charge pressure. Before installation, you should check and adjust this value to match your pump's operating pressure.