SERVAgroup

SERVAcementing

Mixing Skids

Pump Skids

Pump Truck

Pump Trailer

Bulk Blending

Batch Mixer

Liquid Additive
SERVA Recirculating Mixing System
Manual System Only

Dos' and Don'ts'

I. MIXER

  • Do clean after each job by removing the metering valve and washing the dry bulk inlet passage with the wash-up hose
  • Do open water jet after job to allow to drain
  • While displacing, do continue to circulate wash water through mixer and densitometer
  • Do operate the agitator as fast as possible without vortexing fluid in mix tank
  • Do preset the water metering valve to nominal low value before the job - approximately 100 to 120 gpm while putting water in the tub
  • Do not run engine slower than rated speed to make engine last longer
  • Do not mix faster than necessary (usually mixing does not need to be fast while displacing should be)
  • Do not try to adjust both water rate and bulk cement rate. Set water at fixed rate and adjust cement to control density. Control tub level with triplex speed

II. DIFUSER

  • Do wash diffuser from air vent to clean bottom plate and slurry exit vents
  • Do wash around outside of diffuser with hose inserted into mixing tank opening.

III. CEMENT BULK METERING VALVE

  • Do put valve back on mixer after cleaning the mixer after the job (keep it dry)
  • Do open the valve fully at end of job and let bulk air blow out residual cement out of bulk delivery line (from bulk truck) and cement metering valve
  • Do empty valve of excess cement after job
  • Do not wash
  • Do not allow rain or humid air to reach inside the valve
  • If equipped with hydraulic actuator, do not allow actuator pressure to exceed 750 psi. If the valve does not turn, clean the valve before using.

IV. MICRO-MOTION DENSITOMETER

  • Do thoroughly flush the densitometer after the job
  • After cleaning the mixer, do close the valve to the mixer forcing all recirculation flow through the densitometer
  • Do observe the density while washing the densitometer. Continue to wash (flush) the densitometer until a density reading of 8.34 ppg is obtained

V. GENERAL COMMENT

  • Always report problems with the unit in writing to people responsible for maintenance on the same day that the problem was observed
  • Do not put off preventative maintenance such as cleaning metering valve, replacing or topping off oil, replacing filters or replacing wires or hoses that have become damaged