shear pump

Shear pump is a kind of centrifugal pump no need safety valve at outlet. Below is reasons explained from function and pressure source.

Explain on Functions to confirm shear pump no need safety valve

Shear pump is a kind of centrifugal pump. Drilling mud get a certain amount of kinetic energy while leaving impeller under the impeller rotating centrifugal force. Mud also get some certain of pressure in the pump housing, the pressure does not vary with the change of time, pump outlet size, but only depends on impeller structure, size, and rotating speed. As the pressure at shear pump outlet is not vary per pump flow or working condition. It is no need to match safety valve.

Explain on pressure to confirm shear pump no need safety valve

Driving motor and shear pump connected directly with belt. Design speed of impeller is 2200RPM (max.). Under normal working situation, like for 60hz motor, max. speed of shear pump impeller is 1800rpm, much smaller than the design speed. The maximum pressure generated from high speed rotating of impeller centrifugal force is constant. The max. shear pump pressure is 0.47MPa. The outlet pipeline and pump casing can surely withstand the pressure. In this case, it is no need to match safety valve.

Even in the case of the outlet is blacked or the valve is closed, pressure generated from the impeller rotating is larger than pump outlet, drilling mud cannot be discharged, and circulated within pump housing under the rotating force of impeller. If the outlet is blacked or the valve is closed, and mud circulated within the pump housing for a long time, the worst condition is to increase the temperature of pump housing in some degree. The pump pressure will not increase. Therefore, it is no need for mounting safety valve in shear pump outlet pipe.


1500HP land drilling rig usually match 2000bbls mud system. The mud system will have complete full 4 stages solids control equipment and with 5 steps separation process.


Equipment included in 1500 hp land drilling rig mud system:

1) First stage solids control – Shale shaker GNZS594E / GNZS703E linear motion, 3 each

2) The second & third stage solids control – Mud cleaner GNZJ594E-3S-16N / GNZJ703E-3S16N, 1 each

3) Vacuum degasser GNZCQ360 to remove gas from drilling mud before enters into mud cleaner desander / desilter cone.


4) The fourth stage solids control – Decanter centrifuge, 2 each

 One decanter centrifuge GNLW452S in middle speed for barite recovery.

 Another decanter centrifuge GNLW363 in high speed to separate the low gravity mud.

5) Jet mud mixing & shearing mixing system, with GN high efficiency centrifugal pump and shear pump for chemical shearing and mixing.

6) 7 each Mud tanks: shale shaker tank, decanter centrifuge tank, suction tank, mixing tank, shearing tank, storage tank 1 or 2 each

Above is the standard 2000bbls mud system for 1500 hp land drilling rigs. GN Solids Control can make customized mud system per user’s special requirements. If you need more information of other size land drilling rig mud system, you can visit GN website or send mail to