Optimization of the core features of the 7725i liquid chromatography injection valve

1. Core technology: no interruption and precise control

• Patented MBB continuous flow technology
  

1. Adopting Rheodyne's Make-Before-Break (MBB) patented design, the mobile phase is kept continuous when switching between sampling and injection, eliminating the flow interruption problem when switching traditional valves, reducing pressure fluctuations by more than 50%, and ensuring baseline stability.
   
2. Suitable for high-sensitivity analysis (such as trace detection) and high-pressure systems (UHPLC), avoiding instantaneous impact on chromatographic columns and detectors.
   

• Single-point pressure adjustment system
  

1. The pressure knob is integrated at the back of the handle to quickly adjust the sealing pressure (34-48MPa) to adapt to different mobile phase viscosities and flow rate requirements.
   
2. The optimized contact design between the sealing pad and the stator reduces friction loss by 60% and increases the service life to more than 100,000 times.
   

2. Intelligent control and convenient operation

• Built-in position sensor switch
  

1. Only for models with the suffix i (such as 7725i), it provides an electronic trigger signal to achieve synchronous control of injection action and chromatograph data acquisition, RSD≤0.5%.
   
2. Supports manual operation or remote electronic control, compatible with laboratory automation workstations.
   

• 30° wide port flow path design
  

The port connection angle range is expanded, suitable for a variety of pipeline layouts (such as multi-column combination or complex method development), and reduces the dead volume of the flow path.

3. Flexible configuration and high compatibility

• Diversification of quantitative tubes
  

1. Standard configuration 20μL quantitative tube, support 1-5μL micro-injection; optional 2μL ultra-micro quantitative tube to meet trace analysis needs (such as biological samples or low-concentration environmental pollutants).
   
2. Supports 'partial liquid filling method' (liquid filling volume is 75% of the quantitative tube) and 'full liquid filling method' (liquid filling volume ≥ 3 times the quantitative tube), flexible adaptation to different experimental scenarios.
   

• Corrosion resistance and wide pH adaptability
  

1. Standard material: 316 stainless steel valve body + Vespel rotor (temperature resistance 80°C, pH 0-10);
   
2. High pH option: optional PEEK material rotor, resistant to pH 0-14, compatible with strong acid/alkaline mobile phases (such as ion pair reagents or alkaline drug analysis).
   

4.  Safety, durability and maintenance optimization

• Ultra-high pressure tolerance and stability
  

1. The maximum working pressure is 48MPa (5000psi), suitable for conventional HPLC to ultra-high pressure LC systems.
   
2. Double sealing structure design, resistant to temperature fluctuations (-40°C to 80°C), to avoid leakage caused by high temperature thermal expansion.
   

• Quick maintenance and pollution prevention and control
  

1. The sealing pad and stator support tool-free replacement, maintenance time <5 minutes.
   
2. Automatic backflush function after injection (optional), residual rate <0.01%, suitable for continuous high/low concentration alternating injection.
   

Applications and user value

• Precise analysis: Repeatable detection of trace substances such as drug metabolites and environmental pollutants (RSD≤0.5%).
  
• High-throughput laboratory: Load-Inject switching is completed within 30 seconds, and automatic arrangement of multiple queue samples is supported.
  
• Compatible with complex systems: Analysis under harsh conditions such as strong acid/alkaline mobile phases and high-salt buffers.