Maxifluss Rotary Plug Valve VETEC Type 73.7 Double eccentric control valve for process engineering and industrial applications Valve size DN 25 to DN 5 NPS 1 to NPS 2 Nominal pressure PN 63 to PN 16 ANSI Class 6 and 9 Temperature 1 to 4 C 148 to 752 F Valve body made of Cast/carbon steel or Stainless cast/carbon steel Seat version Metal sealing, armored or unarmored The valves can be equipped with different accessories, such as positioners, solenoid valves and other accessories according to VDI/VDE 3845. Standard version For temperatures from 1 to 4 C ( 148 to 752 F) Version Flanged version Image 1: VETEC Type 73.7 Maxifluss Rotary Plug Valve (example with mounted Type R Actuator) DN 25, PN 63 to PN 16, face-to-face dimensions acc. to EN 558-1, Table 8, Series 2 DN 4 to DN 5, PN 63 to PN 16, face-to-face dimensions acc. to EN 558-1, Table 3, Series 15 NPS 1, Class 6, face-to-face dimensions acc. to EN 558-1, Table 17, Series 39 NPS 1½ to NPS 2, Class 6 to Class 9, face-toface dimensions acc. to EN 558-1, Table 3, Series 15 Further versions TA-Luft packing/double packing Special materials for body and trim Noise-reducing features Flange version with tongue/groove, male face/female face according to EN 192-1 RF and RTJ according to ANSI Versions for higher and lower temperatures on request Image 2: Sectional drawing Type 73.7 Rotary Plug Valves Created: 29-3-4 Page 1 of 5
Principle of operation The shaft/plug arrangement is eccentric (Figs. 3 and 4). The double-eccentric design of the Maxifluss rotary plug valve is achieved in combination with the offset of the plug's pivot. When turning the plug shaft from closed position in opening direction, the double-eccentric design allows the plug to lift off the seat smoothly without initial breakaway torque. The valve is not opened suddenly and shows a stable control response even with small opening angles. The rotary plug valve can be used for both directions of flow. For gases and vapors, the direction of flow is FTC (medium closes). The flow coefficient depends on the opening angle of the valve. Using positioners or cam disks, the natural characteristic of the Maxifluss rotary plug valve can be modified to achieve a linear or equal-percentage characteristic (Figs. 5 and 6). Image 3: Double-eccentric principle Fail-safe action In combination with the Type R/M/AT/S Rotary Actuators, the control valve has two fail-safe actions, which become effective when the piston is relieved of pressure or when the supply air fails. Valve CLOSED without supply air: Maxifluss rotary plug valve is closed when the supply air fails. Valve OPEN without supply air: Maxifluss rotary plug valve is opened when the supply air fails. Installation Observe the direction of flow indicated by the arrow on the valve body. Image 4: Plug movement with double-eccentric arrangement 1 1 9 9 8 8 7 7 Kv-Value in % 6 5 Kv-Value in % 6 5 4 4 3 3 2 2 1 1 1 2 3 4 5 6 7 8 9 1 1 2 3 4 5 6 7 8 9 1 Angle of rotation in % Control signal in % Image 5: Natural characteristic Image 6: Equal-percentage and linear characteristic Type 73.7 Rotary Plug Valves Created: 29-3-4 Page 2 of 5
Table 1: Technical data Maxifluss Type 73.7 Valve size DN 25 to DN 5 NPS 1 to NPS 2 Style Flange Flange Flange pressure rating PN 63/1/16 ANSI Class 6/Class 9 Max. operating pressure 16 bar 16 bar Overall length DN 25 DN 4 to DN 5 NPS 1 (Class 6 NPS 1½ to NPS 2 only) EN 558-1, Table 17, Series 39 EN 558-1, Table 8, Series 2 EN 558-1, Table 3, Series 15 Flange bore/form DIN EN 1591-1/DIN 25 ASME B16.5 Seat ring EN 558-1, Table 3, Series 15 Direction of flow from the front: FTO Direction of flow from behind: FTC Characteristic Equal percentage or linear (using cam disk or positioner characteristic) On/off valve Rangeability 2:1 Temperature range Medium: 1 to +4 C Opening angle 75 Table 2: Materials Body 1.619/A216 WCC 1.448/A351 CF8M Shaft 1.444 Plug 1.444/Stellite 6 Trunnion bearing 1.444 Seat ring 1.444 armored with carbide metal Seat holder 1.444 O-ring on seat FPM 8 VR1 Bearing bushing 1.444/plastic Packing 1.444 O-ring FPM 8 VR1 Screw plug 1.444 Screw plug seal 1.444 Trunnion bearing seal Graphite/stainless steel/ptfe Packing PTFE/graphite Type 73.7 Rotary Plug Valves Created: 29-3-4 Page 3 of 5
Table 3: Kvs and Cv coefficients 3a: Seat with metal sealing DN 25 4 5 8 1 15 2 25 3 4 5 NPS 1 1½ 2 3 4 6 8 1 12 16 2 Flow rate 1 % Kvs 16 4 8 245 37 685 95 1925 268 42 72 Cv 19 47 94 286 43 8 111 2238 3116 4883 8114 Seat Ø (mm) 18 26 36 6 76 15 135 17 21 29 37 6 % Kvs 1 24 48 147 22 41 57 123 164 252 4212 Cv 12 28 56 171 256 477 663 143 197 2932 4868 Seat Ø (mm) 16 21.5 29.5 5 6 86 16 146 163 225 286 4 % Kvs 6 16 33 15 15 275 38 77 17 168 288 Cv 7 19 38 122 174 32 442 895 1244 1953 3238 Seat Ø (mm) 14 18.5 25.5 44 53 73 88 126 133 184 234 25 % Kvs 4 12 2 63 93 179 24 48 67 17 1755 Cv 5 14 23 73 18 27 277 555 775 1237 228 Seat Ø (mm) 1 16 21 37 45 62 73 12 116 16 185 Table 4: Weight in kg (without actuator) DN 25 4 5 8 1 15 2 25 3 4 5 NPS 1 1½ 2 3 4 6 8 1 12 16 2 Weight (kg) 16 28 36 55 73 165 249 382 63 129 23 Table 5: DIN face-to-face dimensions PN 63 PN 1 PN 16 DN 25 4 5 8 1 15 2 25 3 4 Length (mm) 23 24 25 28 3 35 4 45 5 6 Table 6: ANSI face-to-face dimensions Class 6 Class 9 NPS 1 1½ 2 3 4 6 8 1 12 Length 21 / (mm) 254 24 25 28 3 35 4 45 5 Type 73.7 Rotary Plug Valves Created: 29-3-4 Page 4 of 5
Order specifications: Type Valve size DN... Nominal pressure PN... Body material Seat version Metal seal Characteristic Equal percentage or linear Kvs/Cv Direction of flow Standard: FTO Reversed FTC Actuator Type Type of mounting Mounting location of actuator Fail-safe action when supply air fails Fail-close Fail-open Max. differential pressure for... bar actuator Supply air... bar Bench range... bar Accessories e.g. positioners, limit switches, solenoid valve etc. Others e.g. special version, certificates, approvals etc. Type 73.7 Rotary Plug Valves Created: 29-3-4 Page 5 of 5