Spherical Expansion Vessel
Spherical expansion vessels and booster pump kits for small booster pumps, hot water pumps, and combi boiler systems: compact models from 2 to 24 liters.
Products (7)
- 24 L Spherical Pressure Tank Kit, Booster Pump Connection Set – $47.24
- 2 L Hot Water Booster Pump Expansion Vessel, 95 ℃, Burst-Proof – $11.40
- Forza FRZ-TGPYK Automatic Booster Pump Spare Ball (TGP 125 Compatible) – $12.00
- Hot Water Expansion Vessel, 2 L, 90°C, Non-Burst – $10.37
- Nortek 24 L Spherical Pressure Tank and Expansion Vessel, 10 Bar – $54.00
- TA24 Spherical Pressure Tank, 24 L, 1'' Connection, 8 Bar – $31.91
- TU 8 Vertical Pressure Tank, 8 L, Connection Size 1/2" - 3/4" - 1" – Request a quote (out of stock)
Brands: Uzman · Forza · Nortek
What is a spherical expansion vessel?
Spherical expansion vessels are pressurized tanks with a round body and compact design. They are manufactured in very small capacities starting from 2 liters up to 24 liters. They are used to provide expansion volume in small domestic booster pumps, hot water pressure pumps, automatic TGP-type booster sets, and combi boiler and solar energy systems. Because they take up very little space, they can be mounted in tight spaces, inline on a pipework run, or directly on the body of the equipment.
Applications
- Small booster pumps: Prevents the pump from starting every time a tap is opened and stabilizes pressure.
- Hot water lines: Small hot-water-rated tanks reduce pressure fluctuations in solar energy pumps.
- Combi boilers and small heating circuits: Accommodates the expansion of heated water.
- Spare part: On some automatic booster sets, the spherical tank mounted on the pump can be renewed with a compatible replacement sphere.
Booster pump kits include the tank, a five-way connector, pressure switch, and pressure gauge, simplifying installation.
Points to consider when selecting
The tank's suitability for the intended water type (drinking water or heating), maximum operating temperature, and pressure rating must be checked in the product specifications. Tanks designed for hot water are manufactured to withstand higher temperatures. The connection size (1/2, 3/4, or 1 inch) must be compatible with the existing pipework. When purchasing a replacement sphere, choose the model with the same capacity and connection type as the existing tank. Because small-capacity tanks store a limited amount of water, vertical or horizontal expansion vessels are more suitable for high-consumption points.
Frequently asked questions
Why do small spherical tanks fail frequently?
Failure to regularly check the air pressure can cause the diaphragm to flex excessively and eventually tear. An annual pressure check extends the tank's service life.
What is a 2-liter tank used for?
Because of its very small capacity, it is used not so much to store water as to reduce pressure fluctuations and prevent the pump from starting and stopping abruptly.
How is the air pressure of a spherical tank set?
With the water side depressurized, the valve on the tank is checked with a pressure gauge; air is added with a pump if necessary. The value should be slightly below the system's cut-in pressure.
What does a booster pump kit include?
Kit contents vary by model; they typically include a tank, five-way connector, pressure switch, and pressure gauge. Check the parts list in the product description.