Doc No: OMM50002312
Rev: C Page 27 of 54
Subject to contractual terms and conditions to the contrar
y, this document and all the information contained herein are the confidential and exclusive
property of FMC Technologies, and may not be reproduced
, disclosed, or made public in any manner prior to express written authorization by FMCTI.
combination pulling and twisting motion.
7. Place the flats on the bottom of the piston
holder (39) in a vice or clamp securely.
Using the FMC piston tool (A5049), unscrew
the piston assembly nut (53) and remove.
The piston cup (38) and piston retainer nut
(50) may now be removed.
8. Inspect all parts for damage or unusual
wear. Ensure that the interior surface of the
cylinder (37) is smooth and free of cracks or
grooves. New piston cups (38) will fail prematurely if installed in liners with
damaged bores. FMC strongly recommends that all three piston cups be
replaced, not just those that show signs of leakage, whenever this type of service
is performed. This will maximize operational time between service intervals.
Service Tip – Due to the large uninstalled diameter, Type B piston cups on W11 pumps cannot be
inserted through the fluid end without the risk of damaging the sealing surface of the cup. Any
pump with Type A cups is not affected and you can follow this procedure without referencing
the Service Tips below.
Service Tip – To perform service on W11 pumps equipped with Type B pistons, the fluid end must
be removed and the liners must be taken to a bench or other work area for assembly. Follow
the steps outlined in Section 10.2, "Removing the Fluid Cylinder" for information about this
procedure.
Service Tip – Piston assemblies in W11 pumps must be
installed in the piston liners using a press or vice as
shown to the right. Be sure to protect both ends of
the assembly with soft vice jaws, wood blocks, or a
suitable non-marring material to ensure the
components are not damaged during this process.
Service Tip – Press the piston assembly into the liner
until the sealing lip has just entered the front of the
liner. Use a small amount of glycerin on the ID of
the liner to help lubricate the piston during
installation. After the cylinder with piston has been
installed in the pump power frame, drive the piston
assembly fully to its stop using the FMC piston tool (A5049) and a rubber mallet.
9. Reverse steps 3 through 8 to rebuild the pump after worn or damaged
components have been replaced. FMC recommends that all seals and gaskets
that are disturbed during the service procedures be replaced. This includes the
rod seal o-ring (49) that is located on the piston/crosshead rod shown directly
behind the piston assembly. Some pump models have the o-ring in a groove in
the piston holder instead of a separate seal holder. Lubricate the piston cups and
piston rods during assembly.
To Next Page
Loading...