DynaPrep MDSF Modular Design Split Frame

Clamshell-style Inline Portable Pipe Machine Tool

DynaPrep MDSF Heavy Wall Double-Bevel


From the simplest parting operation to heavy wall form tool beveling, the Wachs DynaPrep MDSF delivers the right amount of power to the right place.

DynaPrep MDSF inverted for use during maintenance and repairs


Designed for field and fabrication pipe work, the Wachs DynaPrep MDSF thrives in extreme conditions.

DynaPrep MDSF being used for pipeline maintenance and repair work


Whether in the air on a pipeline, oil tower, or in containment at a nuclear plant, the DynaPrep MDSF goes anywhere a pipe weld prep is needed.

DynaPrep™ MDSF Standard Model Sizes:

DynaPrep MDSF Models

DynaPrep MDSF Remote Controlled Part and Bevel Operation

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 feature captivated bolt areas and keyway
  • Rotating Ring thickness is consistent across the entire line
  • Separates to fit into narrow/confined spaces
  • Smaller tool slides are available for restricted operating envelopes
  • The aluminum mounting ring makes the machine lighter and more portable.
  • The steel rotating ring allows the machine to deliver more torque for more demanding machining projects


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



Manual Tooling Sheet Installation Guide Product Line Maintenance Manual