With front-loading injectors it is important to use the correct needle when loading the sample loop.An incorrect needle will damage the valve and can cause poor reproducibility. When the needle is too short the tip will not reach the needle seal. When the needle is too small in diameter the seal will not grip tightly enough. Needles with a beveled tip can damage the rotor seal and stator face assembly. The needle should be #22 gauge (0.028” – 0.0285”/ 0.72 mm), and 90° point style (square cut end). Model 3725 requires a #16 gauge (0.0645” – 0.0655”/ 1.65 mm) needle.

NEVER USE A BEVELED, POINTED, OR TAPERED NEEDLE.

Needle specifications are not critical when using a Loop Filler Port to load the sample loop. However, it is important to tighten the needle port fitting around the needle if using a syringe needle with a slightly smaller diameter than 0.7 mm (0.028”). If the loading method used is complete-filling, a syringe without a needle can be used. A syringe fitted with a Needle Port Cleaner can be used with a frontloading valve or with a Loop Filler Port.

Needle port accessories are listed on this page.