Pump and Fluid Systems
Chapter 3: Operations
weatherford.com
23
MP-16 2-Piece 5000 psi January 2013
3.3.2
Knocking in the Fluid end
Most often, knocking is caused by aeration
of the mud. Examine the mud pits for
excessive bubbles, and check any degassing
equipment used. Also check that the mud
return lines terminate beneath the surface of
the mud level in the pit.
Next, check that the charging pump output
is at the proper levels (between 25 and 50 psi
during operations). Run water over the
packing. If this causes the knocking to stop,
then the packing is loose or worn, and should
be replaced. Also check that there are no
restrictions in the suction line, and that both the
suction and discharge strainers are sufficiently
clear to allow fluid to pass through. If plugged,
clean and reinstall.
If this does not solve the problem, then shut
down the pump and check the valves. Ensure
the valve seats are secured in the bore, and
that neither they nor the valves are misaligned,
washed out or damaged. Also check that the
valve stem guide inserts have not swollen, as
this will cause the valves to stick.
Finally, check the pistons for potential
problems. The piston hubs and piston rod
clamps should be tight and secure, and if not,
adjust as appropriate. Also check that both the
suction and discharge pulsation dampeners are
properly charged and functional.
If none of these solutions help, contact a
Weatherford professional.
