DynaPrep MDSF Medium Diameter Split Frame

Clamshell Pipe Cutters/Bevelers

As the innovator and market leader in split frame technology, at E.H. Wachs we continually develop new products to meet our customer needs. Our split frames are easier to set up, easier to operate, and more powerful, for handling tasks like heavy wall form tooling.

We designed the DynaPrep™ MDSF Medium Diameter Split Frame with accessory modules that vastly expand its capabilities. Building off of our experience with the LCSF Low Clearance Split Frame, the DynaPrep MDSF is engineered to surpass anything available today; benchmarked against the rest and built to be the best. Dyna means power, and E.H. Wachs DynaPrep translates to maximum power in cold cutting portable weld prep machine tools. Our core design principal is power combined with durability.

Rugged and highly portable, E.H. Wachs’ DynaPrep MDSF offers unmatched form tooling capability on heavy wall pipe, including difficult to machine high alloy materials. Designed for cutting, beveling, counterboring, flange facing and more, it's available in eighteen standard models for nominal pipe sizes ranging from 2in - 72in O.D. (DN50-1800), with each model covering a generous 6in range. Sold as complete kits or individual components, the DynaPrep MDSF is available in your choice of pneumatic, hydraulic or electric drive.

DynaPrep™ MDSF Standard Model Sizes:

DynaPrep MDSF Models

DynaPrep™ MDSF Features:

  • Rugged design with vastly increased form tooling capability
  • New gear design withstands force from up to a 10HP (7.5kW) drive motor
  • Ring sizes 20in and below use four clamping feet for squaring
  • New V-Lock ring mating surfaces features angled captivated bolt and keyway
  • Common cross sectional height for tool slide commonality
  • Low sectional height fits in narrow or confined operating envelopes
  • Aluminum fixed ring for portability, steel rotating ring for strength
  • Advanced heat treating and anti-corrosion coatings for enhanced durability
  • Dual row v-bearing construction for precision and strength
  • V-bearings run in a new unique hardened steel dual raceway
  • Dual raceway design evenly distributes force loading no matter the direction
  • Only two sockets 1/2in (13mm) and 3/4in (19mm) needed for setup and operation
  • Ring sizes 24in (610mm) and up use eight clamping feet for squaring and stability
  • Indexed, squaring clamping leg design features a 2in (50mm) stroke
  • Single clamp pad extension covers a 6in (152mm) pipe diameter range
  • Clamp pads mount axially without removing the machine from the pipe
  • U shaped feet pair with push in buttons and points for miter or elbow mounting
  • Screw feet are reversible for mounting versatility, accept push-in buttons & points
  • All models feature replaceable felt wiper for lubrication and to capture chip debris
  • Detented swing bolts allow for fast positioning over inline pipe


E.H. Wachs DynaPrep MDSF split frame clamshell machine tools are the foundation of a complete machining system that performs a wide range of field machining applications, with accessory modules that expand its capabilities. DynaPrep pipe weld prep machine tools can perform precision inline pipe cutting, squaring of pipe ends, and destructive cutting of corroded or damaged pipe and pipelines.

DynaPrep MDSF Pipeline work

Pipe Cutting and Beveling

A pipe cutter by definition, the DynaPrep MDSF pipe cutting machine can simultaneously cut and bevel inline pipe, and when equipped for pipeline applications can quickly prep thin wall and out of round piping. For machining of heavy wall pipe or high alloy materials, additional modules are available that mount without modification to the standard ring set.

Additionally, each MDSF can act as a pipe beveler, beveling inline pipe, open pipe ends and chamfering pipe and casing conductors. In applications where a compound bevel is required, the DynaPrep can act as a compound beveler, beveling with form tools (where the tooling has the finished profile) or single point machining complex preps such as J-prep bevels.

DynaPrep MDSF Counterboring

Pipe and Vessel Counterboring

For counterboring pipe, the DynaPrep MDSF series of rotating lathe machine tools can be outfitted with counterbore modules, enabling counterboring and deep counterbore machining of pipe ends for tapers and transitions.

FFR Flange Facing Module with DynaPrep MDSF on Flange

Flange Facing

Going far beyond basic cut and bevel capability, the DynaPrep MDSF can be equipped with FFC and FFR modules for flange facing, converting the DynaPrep from a pipe cutter into a flange facer to face and resurface flanges, avoiding the need to bring specialized facers onsite. As a flange resurfacing machine, the DynaPrep MDSF can perform bolt face resurfacing, raised face resurfacing, record grooving, and RTJ ring groove creation and resurfacing.

Other Modules

Additionally, a Weld Crown Removal (WCR) module is available for weld crown removal, and an end mill system module is offered that cuts pipe by milling rather than lathe pipe cutting.

Available Modules Request a Quote Request a Rental Quote



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