componente flow control QTO - DVG Automation

QTO Gas over oil Actuators Series

QTO actuators are used for on/off control of any natural gas transmission ball or plug valve by means of a high-pressure natural gas or nitrogen actuator supply. They introduce a new generation of patented mechanism which minimizes wearing effect on all loaded & sliding parts, thus extending overall lifespan.


  • Quarter turn SCOTCH YOKE Mechanism
  • Double Acting
  • Symmetric or canted yoke design
  • Sweet Gas or Sour Gas supply (H2S<=6% ) up to 105 BARG
  • Output Torque Up to 800.000 Nm
  • Gas Over Oil tanks, certified according to International Standard and Customer request
  • Hydraulic manual override
  • Standard temperature range -30°C +90°C, Low temperature version -60°C + 90°C
  • PED 97/23/EC Compliant
  • ATEX 94/9/EC Compliant
  • IP67M, NEMA 4, 4x & 6 as minimum
  • Protected travel stops are standard
  • Actuator in carbon steel – NO Aluminum NO Cast Iron
  • Pressure retaining components and power springs 3.1 Certified according to EN10204
  • Basic control system including Local & Remote control
  • torque limiting device
  • ESD function for low or high pressure
  • ESD function for electric supply failure to SOV
  • Line Break System
  • Opening prevention for high differential pressure across the valve

Key Features & Advantages

Operating Range
  • The Double-acting Actuators are available with individual test and output torque ranging from 1500 Nm (13,250 lb-in) to 800,000 Nm (7,080,000 lb-in)
  • Operating pressure: from 15 barg (290 psig) to 105 barg (1600 psig)
  • Standard design construction allows operating temperature from: -30 degC (-22 degF) to +93 degC (+199 degF)
  • Low temperature option extends operating range down to -60 degC (-76 degF)
Supply medium

Sweet Gas – Nitrogen. Special versions are available for Sour Gas or H2

Scotch Yoke

PATENTED Guide Bar hard chromium plated minimizing guide block swing extending piston rod lifespan under heavy load &/or continuous modulating duty and avoiding any side load on valve stem. Excellent surface finish and self lubricated bearings accomplish higher overall efficiency.

External Tie Rod

External tie-rods, zinc based chemical coating which resists 500 – 1000 hours of salt fog, maintain cylinder integrity.

Symmetric or canted yoke

Gas Over Oil Actuator are available with either symmetric or canted yoke design to cover as closely as possible valve resistive torque profile.

Water ingress protection

Totally enclosed and weather-proof actuator is engineered to meet IP66, IP67 IP67M and NEMA 4 & 4X Specifications.


Cylinder Tube & all structural parts are manufactured in carbon steel material: no cast/grey iron or aluminium. All pressure containing parts are supplied with 3.1 Certificate according to EN10204. Design according to PED (97/23 CE) Directive.

Corrosion Prevention

Cylinder tube is internally nickel-plated lined (minimum 25µm). Nickel-plating layer can be increased upon request.
External coating provides higher reliability in harsh environmental conditions as per ISO 12944 (Expected Durability) and in compliance with NORSOK M-CR-501 requirements.


Teflon ring with internal charging O-ring and external sealing O-ring prevents sticking phenomena after prolonged “stand still” and ensures reduced hysteresis and high sensitivity.


Dual piston PTFE sliding guide, yoke and guide block are mounted with steel Teflon coated bushing to minimize wearing effect and obtain higher sensitivity.


316 Stainless Steel embossed name plate ensures long lasting information preservation, thus guaranteeing lifetime traceability.

Travel stops

External travel stops with protective cap ensure precise angular stroke adjustment 90 -5deg/+5deg.

Lifting point

By means of DIN certified eyelet (three or four off lifting point according to center-body size).

Optional Features

Mounting Pad

Accessory mounting pad allows dual side mounting & does not require any fixing modification in case of rear side assembly.

Manual Override

DVG Automation QYO series can be supplied with hydraulic manual override system. Power is provided by operation of local manual hydraulic hand pump. Open and close action can be selected by means of a directional control valve. Hydraulic manual override by means of two separate hand pumps (1 for open and 1 for close) is available

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DVG Automation Spa

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