D-Series Syringe Pumps - Isco

D Series Syringe Pumps
Section 5 Pump Maintenance & Repair
5.3.3 All other piston seals 1. Access the piston seal as previously described.
2. Orient a new seal so that the spring in the seal is facing up.
3. Slide the seal onto the piston.
4. Replace the piston seal retainer.
5.3.4 The Wiper Seal Although the wiper seal does not normally have to be changed,
periodic cleaning is advisable.
1. Access the cylinder as described previously.
2. Locate the piston (Figure 5-2).
3. Insert a round, 1 8" diameter steel bar or tool of some sort
into the round hole on the side of the piston.
4. Use the tool to twist the piston loose, then unscrew it by
hand.
5. Remove the retaining ring and wiper retainer, then lift off
the wiper seal. Being careful not to scratch any sealing surfaces,
gently break free any solids from the seal and piston.
Rinse all the solids away with distilled water.
5.3.5 To reinstall the wiper 1. Install the piston seal onto the retainer with the spring oriented
towards the retainer.
2. Install the wiper seal onto the piston base with the spring
oriented towards the push tube.
3. Place the piston base onto the push tube.
4. Install the piston seal retainer onto the piston base.
5. Replace the cylinder over the piston and push tube assembly
and screw it into the cylinder mounting block. The cylinder
should be screwed into the cylinder mounting block
until the cylinder snugly bottoms against the piston (the
cylinder will no longer turn).
6. Unscrew the cylinder until the inlet and outlet ports are
lined up as you had them before.
7. Lock the cylinder by tightening the locking screw. Reinstall
covers.
5.4 Wear Ring Cleaning
and Replacement
To replace the wear ring
Although the wear ring does not routinely need to be replaced,
occasionally it becomes worn or damaged, depending on how the
pump has been used. Teledyne Isco recommends that when
replacing the seal or cleaning the piston, check the wear ring for
any signs of deterioration.
1. Follow the instructions in section 5.3, Seal Cleaning and
Replacement, to access the cylinder.
2. Remove the piston seal retainer and slide off the seal. The
wear ring should then slide easily up and off the piston.
The wear ring prevents the piston from direct metal-to-metal
contact with the cylinder wall, and should, therefore, extend at
least 0.010" beyond the circumference of the piston lip. Check the
bottom of the wear ring, which rests on the piston lip, for
extrusion or any unevenness. If there is an indentation (of
5-7