Drillmax ® Gate Valves

(Demco Style)

Drillmax DEMCO® DM Style Gate Valves (Mud Valves)

Drillmax Gate Valves are engineered for the rigorous requirements of today’s oilfield applications. The seats are designed for a complete, tight shut off after every closing cycle. Once closed, line pressure forces the gate up against the downstream port sealing it against the rubber seat. Drillmax also manufactures 7500 PSI Gate Valves modified from a DM Style 5000 PSI design. Both 5000 PSI and 7500 PSI Gate Valves meet and/or exceed the severe pressure demands of deep well drilling.


  • Interchangeable with DEMCO® 5000 PSI mud gate valves.
  • In-Line field repairability. For internal parts inspection, or routine maintenance, the bonnet assembly can be quickly removed from the valve body. Parts are replaced as needed, the bonnet assembly re-installed, and the valve is tested and returned to service.
  • Open and close with ease. Double acting threads and rising stem design mean that opening and closing the gate happens quickly, and with minimal effort to rotate the handle assembly.
  • Sight lens included on larger sizes. Allows viewing of the stem for determination of gate position, while also protecting the stem from dust and dirt.
  • Drop-Tight Sealing. Exclusive seat design provides drop-tight shut-off which is accomplished by metal to rubber sealing.
  • Bi-directional sealing design. The slab gate connects to the stem with a T-slot design, allowing the gate to float in its slot, to seal against either side of the rubber seat. This allows a pressure responsive seal in either direction of flow through the valve.
  • Extensive Quality Assurance verification and testing prior to shipment.

Connection Type

Flanged End Connections – This type of end connection does not require turning or welding the valve. The integral RTJ flanges are connected to matching pipe flanges with bolts and nuts. 

Threaded End Connections – This type of end connection, also referred to as screwed, are suitable for applications up to 7500 PSI. Line Pipe (LP) and Eight Round (8RD) threads are available.
Butt Weld End Connections – This type of end connection is manufactured to match the pipe weld connection. The two beveled ends are butted together and welded in place. Welded connections are best suited for applications where frequent removal from the pipeline is not required.

Welding Warning: Prior to welding, the seat and bonnet seal must be removed from the valve body.

To request a quote on Drillmax Gate Valves (Demco Style) CLICK HERE. Contact Drillmax about our Drillmax Gate Valves (Demco Style).

Looking for another product? We also carry baffle plates.

DM style Mud Gate Valve Repair Kits

Drillmax stocks repair kits and parts ready to ship to your site when needed.

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