Quick Connect/Disconnect Couplers (SVT-QCDC Classic and SVT-QCDC Vario)

QCDC information
Wide Range of Applications
Optimized Sealing Systems
Perfect for Retrofits
SVT QCDC Classic

SVT Quick Connect/Disconnect Couplers rapidly connect the arm to the manifold flange. Connections using standard flanges are relatively time-consuming to make, particularly for large nominal bores. SVT Quick Connect/Disconnect Couplers (QCDC), in contrast, allow lines to be connected to vessels quickly, safely and conveniently.

The various SVT QCDCs are designed for temperatures ranging from -320.8 °F to +482 °F (-196 °C to +250 °C) and come in nominal bores of 6" to 20" (15.2 cm to 50.8 cm). They are vacuum-tested, rated for various pressures (e.g. 150 psi (10.3 bar), 300 psi (20.7 bar), etc.) and certified to relevant international standards.

Every SVT QCDC features wide lead-in chamfers that make it easier to maneuver the loading arm to the manifold flange.


Different material choices can customize SVT QCDCs for different fluids and operating temperatures, whether toxic, aggressive, explosive, cryogenic, or hot. It is equally possible to customize the sealing systems and materials (e.g. FPM, PTFE, CSM, EPDM, PE), although the connecting flange and thus the sealing surfaces of SVT QCDCs are generally made from stainless steel. Redundant seals ensure the tightest possible fit and maximum safety even if the manifold flange is slightly damaged.

The SVT QCDC Vario comes in manual and hydraulic versions. It is not like other couplers, however: It can be instantly adjusted to fit one flange size smaller – all without using tools or swapping out parts. Nothing has to be transported or kept in stock; it just has to be manually unlocked, moved, rotated and relocked. The manual SVT QCDC Vario is operated using simple handwheels, whereas the hydraulic SVT QCDC Vario is equipped with hydraulic drives. The hydraulic SVT QCDC Vario stays safely closed even if the hydraulic power fails but can still be opened manually as needed.

Unlike other systems, the SVT QCDC Vario is installed over the last swivel joint. This placement, together with its low weight, make it the ideal choice for retrofitting marine loading arms. It adds no weight to the triple swivel assembly, relatively speaking, and so normally does not affect the structural integrity of the loading arm. Plus, the loading arm needs no additional hydraulic lines if it is already fitted with an emergency release coupler. All it requires is a software update and a modified connection-and-release safety device. The SVT QCDC Vario raises the bar for safety, speed and convenience at a reasonable cost.

The SVT QCDC Classic also comes in manual and hydraulic versions. It features a highly rugged design for a specific flange diameter. The clamps on the manual SVT QCDC Classic are closed with a short turn of an ordinary box wrench. On the hydraulic SVT QCDC Classic, they are driven by a hydraulic cylinder that operates all the clamps simultaneously at the same speed. A proven mechanical interlock prevents the coupler from inadvertently opening even if hydraulic power fails completely. The hydraulic SVT QCDC Classic is also positioned after the last swivel joint. It can still be disconnected from the flange but is only a few centimeters longer than a manual QCDC.

Highlights – Quick Connect/Disconnect Couplers
  • Nominal bore from 6" to 20" (10.2 cm to 50.8 cm)
  • Operating temperature of -320.8 °F to +482 °F (-196 °C to +250 °C) 
  • Suitable for high-pressure applications
  • Sealing surface made of stainless seal
  • Compensates for minor flaws/damages in the manifold flange
  • Certified to relevant international standards

SVT QCDC Classic

  • Available in manual and hydraulic versions
  • Rugged design for a specific flange diameter
  • Only one hydraulic cylinder needed on the hydraulic version


  • Available in manual and hydraulic versions
  • Quickly adjusts manually to fit one flange size smaller – no tools required
  • No need to stock spare parts
  • Easy to retrofit on marine loading arms – only requires a software update and a modified safety and release device

Hydraulic Quick Connect/Disconnect Coupler

  • Single cylinder design and mechanical interlock ensure that all the clamps move simultaneously and that the QCDC remains safe even if the hydraulic system fails
  • Effortlessly set the opening and closing speeds
  • Highly compact face-to-face length due to flanged configuration after the last ROTAFLEX Swivel Joint

Manual Quick Connect/Disconnect Coupler

  • Easy to operate without applying much force
  • Automatically connects to the manifold flange as early as during the approach
  • Can be adjusted to fit one flange size smaller