Parker ChemTec II, Installation, Operating, & Maintenance Instructions

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Appendix B.
RH Series Pump Head Installation and Maintenance
RH Series Piston Pump Heads - General Information
The ChemTec II FM-120, FM-200 and FM-520 systems use rotating, reciprocating piston pump heads
of various sizes. In a reciprocating pump, the rotating piston moves back and forth inside the cylinder,
sucking in fluid at the inlet while compressing and releasing fluid at the outlet. Flow rates for these
pumps are varied by changing either the motor speed or the stroke length. The RH series of piston
heads are excellent for precise fluid metering.
These ChemTec II systems provide true positive displacement metering. They can handle pressures
up to 100 psi. This style of pump head is appropriate for pumping of suspensions, as well as corrosive
/ non-aqueous liquids and slurries, emulsions, thin solvents, aqueous solutions and non-abrasive
semi-solids. They are also capable of easily handling viscous fluids up to 2000 centipoises. You may
pump fluids up to 10,000 cps by applying feed reservoir/line pressure to avoid cavitation.
NOTE: Piston pumps are not recommended for metering of biological fluids, or liquids containing
biological cells or cellular components. High local shear is generated in the fluid along with strong
mechanical agitation, which may destroy cells and fragment large molecular weight components such
as DNA or large protein molecules.
Materials of Construction
RH series pump heads have cylinder bodies and fittings made of either Kynar or Tefzel. The piston
and cylinder liner are ceramic, except for the RH00 models, which use a stainless steel piston with a
sintered carbon cylinder liner. An “LF” designation refers to a “Low Flow, low dead volume” pump
connection, that utilizes ¼-28 HPLC nuts and ferrules with 1/8” or 1/16” tubing instead of
compression fittings designed for 1/4” OD tubing.
Installation
The following are directions for dismounting and installing a new pump head on a ChemTec II. The
ChemTec II will come with the head already installed and ready to use.
1. Disconnect the power from the ChemTec II.
2. Remove the two screws (6-32 x ½ RH) from underneath the ChemTec II between and just behind
the front feet.
3. Remove the four screws (6-32 x 3/8” FH) from the face plate at the front of the ChemTec II.
4. Carefully remove the pump/motor subassembly from the ChemTec II. Disconnect the motor
cable from the pc board making note of how it was connected before completely removing it from
the chassis.
5. Loosen the set screws on the head side of the coupler.
6. Using an offset screwdriver (It has a tip bent at right angles to the shaft), remove the head
mounting screws (8-32 x ½”) from the rear of the face plate, allowing the head to be removed.
7. Reassemble the new head by reversing this process.
8. Test the ChemTec II with the new head installed after making fluid connections to both ports of
the pump head. Do not let the pump head run dry without fluid for prolonged periods.