Agilent G1311-67701 is an original Multi-Channel Gradient Valve (MCGV) assembly for liquid chromatography. The valve is part of the low-pressure gradient section of a quaternary HPLC pump and controls solvent selection and proportioning before the mobile phase enters the high-pressure pump assembly. Agilent lists it as a repair part compatible with 1200 models.
In the quaternary pump hydraulic path, solvents flow from the reservoirs through the degasser to the MCGV. The valve creates the programmed solvent composition on the low-pressure side before the mobile phase enters the active inlet valve and pump head.
Function in the Quaternary Pump
The Agilent 1200 Series Quaternary Pump uses a four-channel gradient pump with a high-speed proportioning valve. Solvent composition is generated by low-pressure mixing before the pump delivers the mobile phase to the high-pressure side.
The MCGV controls solvent flow from:
- A
- B
- C
- D
This allows binary, ternary, and quaternary gradients to be generated according to the LC method.
Note: G1311-67701 is the standard MCGV. Bio-inert configurations use the separate G5611-67701 Bio-Inert Multi-Channel Gradient Valve.
Buffer Handling
When buffers or salt solutions are used, Agilent recommends regular flushing of all valve channels with water to prevent salt precipitation and blocked or leaking channels.
For mixed buffer/organic workflows, the recommended arrangement is:
- aqueous/buffer solution on a lower valve port,
- organic solvent on the upper port directly above it,
- for example A = buffer, B = organic solvent.
Technical Specifications
- Product: HPLC Multi-Channel Gradient Valve Assembly
- PN: G1311-67701
- Abbreviation: MCG / MCGV
- Technique: LC / HPLC
- Function: Solvent selection and proportional mixing
- Solvent Channels: 4
- Channels: A, B, C, D
- Gradient Type: Low-pressure quaternary mixing
- Manufacturer Compatibility: Agilent 1200 models
- Version: Standard, non-bio-inert
- Part Type: Repair / service part
