Fluctuating pressure, high delta psi with Alliance 2695 SM or 1515 pump - WKB21017
Article number: 21017
SYMPTOMS
- Fluctuating pressure
- High delta psi (400 psi)
- Replacing the Solvent Bottle Filter, 1/pkg (700003615]) does not solve the problem
- Solvent present on pump head body (outside of seals)
- Solvent leak seen at base of pump head
ENVIRONMENT
- Alliance HPLC System
- 2695 Separations Module
- 1515 Isocratic HPLC Pump
- 1525 Binary HPLC Pump
- 515 HPLC Pump
CAUSE
Faulty plunger seals
FIX or WORKAROUND
- Remove the solvent line filter from the mobile phase bottle.
- Using two 5/16-inch wrenches, disconnect the tubing that goes into the inlet and outlet check valves.
- Using a 5/32-inch hex wrench, remove the two support screws that hold the pump head onto the support plate.
- Carefully slide the pump head off the pump.
- Use a non-metallic tool to remove the clear seal and washer from the pump head, being careful not to scratch the pump head.
- Place a new washer and plunger seal on the pump head seal orifice:
- 2695: Plunger Seals Replacement Kit (Std-Yellow) 2/Pkg (WAT270938])
- 1515: Clear-100™ Plunger Seal (WAT022934])
- Wet the new seal with methanol, and then, with a gloved hand, use the flat part of your thumb to press the seal into the pump head.
- Carefully install the pump head onto the plunger support and fasten it with the two 5/32-inch hex screws. Tighten evenly until both are tight, to prevent excessive torque on the plunger.
- Prime the pump with methanol.
- Using a restriction device such as an old column, pressurize the seals to at least 3000 psi for 10 minutes.
- Confirm that the pressure is stable.
ADDITIONAL INFORMATION
Also replace the plunger if signs of wear or damage are present.