Page 20 of catalogue Butterfly valves of Erhard GmbH & Co. KG

Safety comes first
Return flow prevention For special applications such as manifolds with parallel Pumps or riser Pipes, Butterfly valves from DN 150 can also be combined with suitable checking protection to prevent return flow. ERHARD Check valves are produced to the same high standards and with their stable bodies, streamlined valve disc, shafts protruding on both sides and with maintenance-free supports as well as a robust key connection between the shaft and disc, they are the perfect addition for ERHARD ROCO Premium or ERHARD EAK butterfly Valves. Weight-loaded Hydraulic actuator Both ERHARD ROCO Premium and ERHARD butterfly valves are available with an optional hydraulically controlled weight-loaded actuator with a compact design. Its uses include, among other things: A Pipe burst protection A Combined discharge and nonreturn valve A Turbine inlet protecting valve A Quick-opening valve All equipment used for hydraulic control of the closed hydraulic system such as pumps and valves are fixed directly to the cylinder with few pipes. To quickly reduce the flow in a pipe, the first damping phase (approx. 70 % of the closing angle) is run through quickly, the remaining 30 % is highly throttled to keep dynamic pressure peaks low (closing time characteristic 2-stage). The opening process of the butterfly valve takes place with the lifting of the weight-loaded lever by the hydraulic cylinder by means of an electric hydraulic pump or manual oil pump.

Weight-loaded hydraulic actuators are available for nominal sizes from DN 200 to 3000. They can be combined with both ERHARD ROCO Premium and with ERHARD butterfly valves.

Installation suggestion for ERHARD check valve – ERHARD butterfly valve DN Direction of flow 150 200 250 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 ERHARD check valve Intermediate support ERHARD butterfly valve 1500 1600 1800 2000 L 210 230 250 270 310 350 390 430 470 510 550 590 630 670 710 750 790 870 950 150 150 150 225 300 400 500 600 650 750 800 900 1000 1100 1200 1300 1400 1600 20 45 70 118 165 215 260 315 360 410 455 515 560 615 660 705 815 915 10 15 30 40 55 50 60 70 80 90 110 130 9 41 63 95 120 150 180 210 225 270 295 320 360 385 445 505 L1 a b c

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