Case study: the hydrant connection of Aquaform Ltd. (Biel-Benken, Switzerland)
Aquaform Ltd. is a Swiss company producing "Rückflussverhinderer Typ EA". The fire brigades in other countries do not all use the same product. The equivalent or approximate translation would therefore be a valve used as a connection to the fire hydrant.
This product has been specially designed by Aquaform for fire brigades. Since 2015 it has been equipped with the Stop Silent non-return valve produced by Lasso Technik.
The system ensures hygiene requirements for firefighting operations
The Stop Silent check valve consists of a stainless steel cone and a rubber membrane.
The valve cone serves as a raw filter to protect the system. The soft closing rubber membrane impresses with its high reliability and tightness. StopSilent valves are designed for a non-return pressure of 16 bar. Incorporating a Stop Silent valve into such a system allows the pressure due to fluid displacement to be reduced.
A product that complies with the latest standards!
The product fully complies with the latest standards of the Swiss Gas and Water Industry Association (SVGW), namely the W5 directive. The W5 directive covers all aspects of water supply for firefighting. (Edition in October 2018)
Article 6.6.2 of the Directive - Prevention of backflows
"When purchasing hydrant equipment, a type EA check valve must be installed directly on the hydrant! The water flow pressure from the hydrant should ideally be 3 bar, but at least 2 bar. "
The Stop Silent non-return valve can withstand a pressure of up to 16 bar.
Functioning of the non-return valve:
The diaphragm is located in the perforated support cone and its sealing lips are on the inner surface of the cone and therefore make the return flow of water impossible.
As the pressure increases in the direction of flow, the diaphragm deforms and flow occurs. When the flow rate decreases, the diaphragm returns to its original position and closes the valve again.
The membrane of our Stop Silent check valves moves like a jellyfish. It deforms slightly to allow fluids to pass in one direction and withstands high pressure in the opposite direction.
Stop Silent - Lasso Technik SA :
No moving mechanical parts, soft closing, no water hammer, low pressure loss, little maintenance required, reliable and durable.