Non-return valves for flanged valves and screw connections
Check valves from the manufacturer for flanged valves and screwed connections with a high-quality plastic diaphragm to protect against the backflow of fluids.
Technical features of our non-return valves
The non-return flaps of Lasso Technik AG are equipped with a membrane that reliably prevents the backflow of liquids and gases. When the membrane is closed, only a low noise level is generated, so water hammer is excluded. This backflow prevention device guarantees reliability at all times since it works even when the water contains granules or sand. In addition, our backflow preventers act as raw filters and secure pumps and systems of this type. The check valve is extremely durable because no moving mechanical parts can wear out because it does not contain any.
Non-Return Valves - Technical Data
- Flow velocity: (gases) 15 m/sec
- Dimensions: from DN 20 to DN 600
- Aqueous, oily, acidic and basic liquids
- Nominal pressure: 16 bar
- Heat degrees: -20° to +200°C (no steam)
- Flow velocity: (Fluids) 2.5 m/sec.
Installation examples of non-return valves
The membrane is located in the perforated support cone and the sealing lips rest on the inner surface of the cone. When the pressure increases, the membrane deforms and allows the fluid to pass through. In the event of a pressure drop, the diaphragm moves to the initial position and closes the cone check valve.
Check valve AS 41 - DN 25 to DN 200
- for standard fittings
- for mounting in flat-sealing unions
Check Valve SFL Flange - DN 40 to DN 200
- hot-dip galvanized, powder-coated or stainless steel
- for flange valves from 40 to 200mm
Check valve AS 54 - DN 40 to DN 200
- for retrofitting
- fast and cheap
- without structural changes
Check valves MKV multi-cone - DN 150 to DN 600
- powder coated or stainless steel
- for pipe diameters from 150 to 600mm
- as welded construction
Check valve AS NU - DN 25 to DN 100
- for small flange diameters
- with O-ring on the outside of the flange
- for sanitary and industrial fittings
Materials of the non-return valves
Check valves have a diaphragm made of approved materials depending on the application.
Check valves with a Viton® Fluorcarbon membrane:
- Temperature resistant -20 to +220 °C
- For chemical industry
- Acid resistant
Check valves with nitrile rubber diaphragm NBR:
- for thermal cogeneration plants
- for petrochemistry
- for solar technology
Check valves with ethylene-propylene-diene rubber diaphragm EPDM:
- short term sterilisation with steam possible
- for hot and cold water
Check valves with silicone diaphragm VMQ:
- Water temperatures up to 100°C
- For food industry and drinking water
- Cold resistance down to approx. -60°C
- Hot air temperatures up to +210°C
Check valves with a fluorosilicone membrane FVMQ:
- weather-resistant
- temperature-resistant
- unalterable
- ozone-resistant
Non-Return Valves - Fields of Application
Non-return valves from Lasso Technik AG have a wide range of applications
- petrochemistry
- process engineering
- solar technology
- food industry
- water treatment
- groundwater pumps
- heating installations
- fire protection systems
- waterworks
- sanitary facilities
- chemical industry
- irrigations
Further areas of application for non-return valves
- cooling water systems
- pumping stations
- water supply
- house installation
Manufacturer, dealer, service provider
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Daniel Rohrer
CEO - Lasso Technik AG
CEO - Lasso Technik AG