Liquid Phase Pump: Comprehensive Analysis of Principles, Brand,Usage, Common Faults, and Repair Methods

1. Introduction

The liquid phase pump, a device used to transport liquids from low-pressure to high-pressure areas, finds wide application in chemical analysis, pharmaceuticals, food processing, and more. Its operation principles are rooted in fluid mechanics, utilizing mechanical motion or pressure waves to induce liquid flow and propel it from low to high-pressure zones. Common types, such as centrifugal and positive displacement pumps, are renowned for their stability and durability.

2. Working Principles

The core principle of liquid phase pumps involves applying pressure to liquids through mechanical components (e.g., plungers, pistons, or impellers) to generate flow. Taking positive displacement pumps as an example, they utilize the reciprocating motion of a plunger within a pump cylinder, coupled with sealing rings, to achieve liquid intake and discharge. As the plunger retracts, pressure in the cylinder drops, allowing liquid intake; as it advances, pressure rises, expelling the liquid.

3. Usage Methods

Installation & Preparation:

• Place the pump on a stable platform, ensuring all connecting pipes are correctly installed and well-sealed.
• Check that solvent bottles are filled with the required liquid and positioned above or higher than the pump to aid gravity-assisted feeding.

Pre-Start Check:

• Inspect power connections for stability and the pump for air bubbles or impurities.
• Pre-flush the system with an appropriate solvent to remove potential contaminants.

Operation Control:

• Set pump parameters such as flow rate and pressure according to experimental needs.
• Observe pump operation after starting, ensuring no abnormal noises or leaks.

Routine Maintenance:

• Regularly replace solvents and inspect/clean critical components like filters and check valves to prevent blockage and wear.

4. Common Faults & Repair Methods

• Pump Head Air Bubbles:
  • Phenomenon: Unstable system pressure, fluctuating flow rate.
  • Solution: Use an ultrasonic cleaner to degas the mobile phase; open the drain valve and use the PURGE function or a syringe to eliminate bubbles.
• Check Valve Fault:
  • Phenomenon: Unstable pressure, poor liquid delivery.
  • Solution: Clean the check valve online or with an ultrasonic cleaner. Replace it if the ball is severely worn.
• Inlet Filter Blockage:
  • Phenomenon: Poor liquid intake, increased pressure.
  • Solution: Remove the inlet filter from the delivery tube, clean it with isopropanol and ultrasonics, or replace it.
• Plunger Seal Leakage:
  • Phenomenon: Liquid flows out from the rear of the pump head, increasing the cleaning solution bottle level.
  • Solution: Inspect and replace worn plunger seals to ensure proper sealing.
• Pipeline Filter Blockage:
  • Phenomenon: Increased delivery pressure, decreased flow rate.
  • Solution: Disconnect the pump outlet pipeline, inspect, clean, or replace the filter screen.
• Column Blockage or Contamination:
  • Phenomenon: Continuously increased delivery pressure, abnormal chromatographic peak shape.
  • Solution: Clean or replace the column according to its manual.
• Detector Cell Blockage:
  • Phenomenon: Abnormal detection signals, high baseline noise.
  • Solution: Disconnect the detector cell outlet, clean it internally with isopropanol, and disassemble for cleaning if necessary.

5. Summary

As a crucial device in chemical analysis and other fields, the liquid phase pump’s stability and precise control are vital for experimental results. Proper usage and maintenance can effectively prevent common faults and extend pump lifespan. Regular inspections, timely cleaning, and replacement of worn parts ensure optimal pump performance. For different faults, corresponding repair measures should be taken to ensure smooth experimental processes.

6. Brands and Models Repaired by Longi Electromechanical Company

• Bosch Rexroth
  • A10VSO, A4VSO, A2F, A10VO, A11VO Axial Piston Pumps
  • Controllers: VT-VRPA1-5-1X, VT-MSPA1-1-1X, VT-VSPA2-1-1X
• Parker Hannifin
  • PV Plus, PVP, PVQ, PAVC, F12 Axial Piston Pumps
  • Controllers: IQAN Series, P1/PD Series, Compax3
• Eaton
  • Vickers V Series (V10, V20, V80) Vane Pumps, PVM, TA1919, 420 Series Axial Piston Pumps
  • Controllers: Hydro-Line, AxisPro Series, X20
• Kawasaki
  • K3V/K5V Series (K3V63DT, K3V140DT, K5V200DT), NV Series (NV84, NV111, NV137) Axial Piston Pumps
  • Controllers: K3VLS Control, KAWASAKI KMX
• Danfoss
  • Series 45 (45L028, 45L038, 45L045), H1 Series (H1P042, H1P053, H1P068) Axial Piston Pumps
  • Controllers: PLUS+1®, DP Series, PVG32, EPC Series, VPC Series
• Yuken
  • A Series (A16-FR01, A37-FR01, A70-FR01), PVR Series (PVR1T, PVR2T, PVR3T) Axial Piston Pumps
  • Controllers: EPC Series, VPC Series
• Linde Hydraulics
  • HPR Series (HPR-02, HPR-05), DPVG Series (DPVG-140, DPVG-210) Axial Piston Pumps
  • Controllers: LINC, ESC
• Sauer-Danfoss
  • Series 90 (90L042, 90L055, 90L075), L/K Series (L042, K042) Axial Piston Pumps
  • Controllers: PLUS+1®, MC Series, DP Series
• HAWE Hydraulik
  • V30D, V60N Axial Piston Pumps, MPC Variable Piston Pump
  • Controllers: ESX Series, CAN-IO
• Nachi
  • PVS Series (PVS-0B, PVS-1B, PVS-2B), PZ Series (PZS-3B, PZS-4B) Axial Piston Pumps
  • Controllers: NACHI MCE, NACHI NC
• Bucher Hydraulics
  • QX Series (QX21, QX31, QX42), AP Series (AP212, AP315) Axial Piston Pumps
  • Controllers: DPS, NFA Series
• Moog
  • RKP Series (RKP032, RKP045, RKP063) Axial Piston Pumps
  • Controllers: Moog EPU, Moog Axis Control
• Casappa
  • FVP Series (FVP10, FVP20, FVP30), PLP Series (PLP10, PLP20, PLP30) Axial Piston Pumps
  • Controllers: EPC Series, MC Series
• Denison Hydraulics (Parker)
  • T6 Series (T6C, T6D, T6E) Vane Pumps, Gold Cup Series (P14, P24, P30) Axial Piston Pumps
  • Controllers: Gold Cup Controller, Parker IQAN Series
• Rexroth (Bosch Rexroth)
  • A11VO Series (A11VO40, A11VO60, A11VO75) Axial Piston Pumps
  • Controllers: VT-VRPA1-5-1X, VT-MSPA1-1-1X, VT-VSPA2-1-1X

7. Conclusion

Longi Electromechanical Company, with nearly 30 years of experience, specializes in liquid phase pump repairs, ensuring swift restoration of various instruments. We also buy and sell used liquid phase pumps. For inquiries, please contact us.