Butterfly valve (RTAK)


100 – 4.000
10 – 25

Double eccentric flanged butterfly valves with epoxy coating in long or short overall length or in welded steel design for use in the water sector. Durable due to medium-free bearings and wear-resistant, corrosion-proof and infiltration-proof housing seat due to application of armouring. Suitable for use in industrial plants, water treatment, power plants and pressure management.

Operating pressure: max. 25 bar
Operating temperature: -50° C bis + 200° C
Seat-geometric: Double eccentric
Shaft bearing: Self-lubricating 
Inner sealing: soft sealing 
Outer sealing: 
double shaft bearing by means of o-rings for dynamic/static sealing


Absprerrklappe RTAK
Application overview, types of actuation, valve types
Branch of industry RTAK  
Actuation RTAK
Manual control 1
Electrical drive 1, 2
Pneumatic drive 1, 2, 3
Hydraulic drive 1, 2, 3
Drop weight drive 1, 4
Lever & weight  
Oil brake  

1) Open - Close, 2) Controlled, 3) Quick opend - closed, 4) Closed by gravity
5) Forced controlled, 6) Damped

Valve type  
RTAK Butterfly valve “soft seated” double excentric, p max. 25 bar, -58° F to 392° F, DN 100-4000, PN 2,5/6/10/16/25 bar, ANSI 150/300, Material: Carbon steel / SS
Power plant
- Cooling water
- Air condenser
- Heating water
- Steam turbine
- Steam circuit

Water, Sea water
Water dam
District heating  
Steam generation  
Pump station  
Gas, Natgas
Mineral oil
On-shore, Off-shore  
Garbage incineration  
Mining industry
Mechanical engineering
Sugar industry  
Paper industry  

• Recommended application

Product features and benefits

• soft sealing to EN 593
• face-to-face length to EN 558-1, basic series 14 (DIN 3202, F4)
• with flange connection on both sides to EN 1092 / ANSI B16.5 and B16.47
• double eccentric disc mounted in maintenance-free sockets
• corrosion-protected bearing in the body by means of double o-ring seal and closed bearing eyes on the valve disc
• wear-resistant, corrosion-resistant, flow-optimised and infiltration-proof body seat
• replacement of the profile seal possible without dismantling the valve disc
• automatic sealing system with chambered and pressure-supporting profile seal
• vacuum-tight up to 1 Torr
• tight in both flow directions to EN 12266

Material, corrosion protection, versions


• Body: P265GH (1.0425); P355NL1 (1.0566), SA516 Gr.60/70; X5CrNi18-10 (1.4301); X6CrNiMoTi17-12-2 (1.4571)
• Valve disc: P265GH (1.0425); P355NL1 (1.0566), SA516 Gr.60/70; X5CrNi18-10 (1.4301); X6CrNiMoTi17-12-2 (1.4571)
• Inner seal: Perbunan, EPDM, Viton, PTFE
• Outer seal: Perbunan, EPDM, Viton, PTFE
• Butterfly valve shaft: Stainless steel 1.4021
• Body seat: High-alloy build-up welding or wear-resistant, stainless steel, precision machinedother
  materials on request

Corrosion protection

• body: Inside and outside epoxy coating according to GSK guidelines possible
• valve disc: Epoxy coating according to GSK guidelines possible (Exceptions: DN100-125, valve disc made of stainless steel)


• with electric actuator
• with handwheel
• with pneumatic actuator
• with hydraulic actuator
• enamelled or with special coatings on request
• suitable for gas according to EN 13774