CASE STUDY: Drilling Mud Diverter Service

Stationary Core and Covered Seats Protect Against Destructive Media


This is a very demanding service where the mud can include entrained solids such as formation solids, shell, and shavings. Traditional valves expose their seats to this destructive media creating valve failures and costly repairs with long down times. The HCV valve’s stationary core and protected seats has proven to provide an improved solution with installations on multiple continents.


6” HCV Valves were installed as drilling mud diverters – safety systems – on “under-balanced” drilling systems. Test units were initially installed in June 2008. Valves are mounted directly adjacent to the rotating head as primary dump valves in the event down-hole pressure surges to unacceptable levels. When the valves are required to operate they experience the high pressure surge along with all surging material (including mud and entrained solids including formation solids, shell, shavings, etc.) venting through the valve. When pressure stabilizes the valve is required to close and positively block the down-hole pressure.

The count on number of operations is difficult to determine as every drilling operation is unique. The valve design previously used in these applications exposed the seal surfaces to the media and in several cases, when operating (open to close) closed the sealing areas on the entrained solids, significantly damaging seats/seals requiring very expensive repairs.

Valves Supplied
Size 6″ ANSI 600 and 900 Class
Body Material WCC Carbon Steel
Internals Carbon steel – electrolysis nickel plated
Trim Nylon seat/viton seals
Port Full Port
Connections Raised Face Flanged
Service Conditions
Media Drilling mud with entrained solids
Manual/Actuated Pneumatic (Air/Open – Air/Close)
Temperature Ambient to 200 degrees
Orientation Off vertical
Pressure 800 – 2000 psig
Diverter Mud Valves


Within the HCV Valve, the stationary core, maintaining its position protecting the seat surfaces, significantly minimizes potential damage to the seats. When damage is found the cost of repair is significantly less than the valve designs previously used as a result of the Cartridge concept and its ease of repair. Since the initial installation of this test application and its successful results, Chromatic has supplied a significant number of these units operating in drilling systems on multiple continents.