Handling And Storing The Product; Product Introduction; Intended Use; Pumped Liquids - Grundfos GT-U+ Montage- Und Betriebsanleitung

4.1.1 Precharge pressure for heating applications
Heating expansion tanks accommodate the natural
expansion of water as it is heated.
• Tanks in closed-loop heating circuits must be
precharged to system fill pressure.
• Tanks in open-loop heating storage systems
must be precharged to the pressure of the mains
supply.
4.2 Adjusting the precharge pressure
CAUTION
Pressurised system
Minor or moderate personal injury
- Make sure there is no pressure on the
tank before starting any work on the
tank.
CAUTION
Pressurised system
Minor or moderate personal injury
- Never exceed the maximum operating
pressure of the tank.
- Always precharge the tank with air at
ambient temperature only.
The tanks are supplied from the factory
with a precharge pressure. See the tank
nameplate.
Release or add air to set the recommended
precharge pressure.
1. Isolate the tank from the system.
2. Open a drain valve and drain the tank. The tank
must be completely empty to avoid that water
pressure affects precharge readings.
3. Release or add air by means of the tank air valve
to the desired precharge pressure. Use an air
compressor to add air.
4. Reconnect the tank to the system.
4.2.1 Precharge pressure above 4 bar (58 psi)
To precharge the tank above 4 bar (58 psi), follow
this procedure:
1. Isolate the tank from the system.
2. Drain all water from the tank. If the tank pressure
is high, release air to reduce the precharge
pressure to 3 bar (44 psi) before you open the
drain valve.
3. Increase the precharge pressure in steps of
maximum 3 bar (44 psi). After each step,
equalise the system pressure by filling water into
the system.
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5. Handling and storing the product

5.1 Handling the product
See section 3.2.2 Lifting the tank
5.2 Storing the product
Store tanks in a covered, dry and ventilated place,
protected from rain and sun.
Used tanks must be emptied of water before storing.

6. Product introduction

GT-U+ pressure tanks are vertical tanks ranging
from 100 to 3000 litres and available in 10, 16 and 25
bar pressure ratings. The tanks are designed with a
replaceable bladder and built-in pressure gauge. The
pressure tank body is made of steel.

6.1 Intended use

Typical applications include booster systems,
heating expansion and hammer arresting in high-rise
and multistory buildings.
GT-U+ tanks are suitable for use in:
• indoor domestic applications: heated buildings
with a clean atmosphere such as offices, shops,
schools and hotels.
• indoor commercial applications: non-heated
buildings where condensation may occur, such
as storehouses and sports halls.
• outdoor applications with a clean or slightly
contaminated atmosphere, mainly rural areas.

6.2 Pumped liquids

The following liquids can be used in the pressure
tank:
• Potable water, well water.
• Grey water: domestic wastewater from
dishwashers, washing machines, cabinet
showers.
• Water mixture with a maximum of 50 % glycol.