Keep Legionella in check
Legionella is a bacteria that is found in many places but has ideal growth conditions in plants where the temperature in several places is between 25-60°C. Legionella can, by inhalation of atomized water (aerosols), for example, during showering – cause both Legionnaires’ disease (lung disease) and Pontiac fever (flu-like fever disease). Legionnaires’ disease can be fatal especially for people with weakened immune systems.
Legionella growth has several causes
- Dead ends with stagnant water
- Circulation of the water is hindered by lime, sludge, rust etc.
Pipe Center Instruction 017 (Danish) has made a table of the risk of bacteria formation and Legionella conditional on the water temperature, see the table below:
| Temperature | Effect on Legionella Growth |
|---|---|
| Under 20°C (68°F) | Legionella can survive, but most often in a resting state (Legionella can survive in an ice cube) |
| 20°C–50°C (68°F–122°F) | Legionella can grow – the optimum temperature level is 35°C to 46°C (95°F-114,8°F) |
| Over 50°C (122°F) | Legionella can survive, but no growth occurs |
| 55°C (131°F) | Legionella dies within 5-6 hours |
| 60°C (140°F) | Legionella dies within half an hour, but there is an increased risk of calcification |
| 66°C (150,8°F) | Legionella dies within 2 minutes |
Conventional ways of avoiding legionella
There are two common ways of avoiding the risk of legionella buildup.
- A standard Emergency Shower installed in a ramification which requires a weekly flush. If legionella occours, there is no way of protecting the main pipe from contermination.
- A solution that prevents legionella from spreading to the main pipe. A check valve is installed right before the T-piece, and prevents stagnant water, from running back into the main pipe.
OBS: According to the EN 15154 as well as the ANSI Z358.1 norms, emergency showers should be flushed with fresh water. This to clear the supply line for any sediment build up and minimize microbial contamination due to stagnant water. Further, this will verify operation of the unit. The test is recommended to be done weekly.
Conventional ways of avoiding legionella
There are two common ways of avoiding the risk of legionella buildup.
- A standard Emergency Shower installed in a ramification which requires a weekly flush. If legionella occours, there is no way of protecting the main pipe from contermination.
- A solution that prevents legionella from spreading to the main pipe. A check valve is installed right before the T-piece, and prevents stagnant water, from running back into the main pipe.
OBS: According to the EN 15154 as well as the ANSI Z358.1 norms, emergency showers should be flushed with fresh water. This to clear the supply line for any sediment build up and minimize microbial contamination due to stagnant water. Further, this will verify operation of the unit. The test is recommended to be done weekly.
Legionella-safe range based on piping dimension 3/4"
This range is optimal for smaller buildings, where a loss of water pressure isn’t a risk.
Fixed temperature
The water temperature depends on the supply of; cold, warm or tepid water.
Regulation with ceramic headwork
The water temperature can be adjusted by the handle between cold, warm and tepid water.
Regulation by TMV
The TMV provides a pre-set water temperature, via a built-in thermostatic element.
Legionella-safe range based on piping dimension 1 1/4"
This range is ideal for bigger building. It can be placed directly on the main water supply, to ensure that there won’t be any loss in water pressure even with multiple emergency showers and a fire hose on the same pipe.
Fixed temperature
The water temperature depends on the supply of; cold, warm or tepid water.
Regulation with ceramic headwork
The water temperature can be adjusted by the handle between cold, warm and tepid water.
Regulation by TMV
The TMV provides a pre-set water temperature, via a built-in thermostatic element.
We can help you fight Legionella
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