Frequently Asked Questions (FAQs): Finger-Tight Fittings for GC Column Installation

1. Which parts do I need to install a GC capillary column in my instrument?

Restek recommends using parts with finger-tight fittings to make consistent connections quickly and easily. You can find part lists for specific instruments here.

2. Can finger-tight column nut fittings replace my existing fittings?

Yes, in most cases.  For Agilent and Thermo 1300/1310 and 1600/1610 GCs, exchange the OEM fitting for either Restek cat.# 22347 or 22348. For Shimadzu GCs, exchange the OEM fitting for Restek cat.# 27230. For PerkinElmer 590/690 and GC2400 GCs, you must switch out the OEM reducing nut for Restek cat.# 22078 in order to use Hot Swap column nuts cat.# 22347 or 22348. For older Thermo TRACE and Focus GCs and for converting Shimadzu GCs to a standard 1/16”-type ferrule, you can use Hot Swap column nut cat.# 27224, but first must install a new capillary adaptor.

3. Do I need to use a wrench to tighten finger-tight fittings?

For graphite and 60/40 Vespel/graphite ferrules, we have found that the additional torque gained using a finger-tight column nut fitting allows most users to pre-seat ferrules onto the column without using a wrench. But, for 85/15 Vespel/graphite ferrules, a wrench may still be required. Using finger-tight fittings reduces the time and effort needed for column installation and decreases the chance of overtightening the fitting.

4. What are the advantages of using Hot Swap finger-tight column nuts compared to standard finger-tight column nuts or traditional column nuts that require wrenches for installation?

Leak-free connections can be made with any of these fitting styles; however, installing columns using finger-tight column nuts is much faster and simpler than using traditional column nuts that require cumbersome wrenches. Hot Swap finger-tight column nuts make installation even quicker because the heat-dissipating design allows users to change the column without burning their fingers or waiting for the inlet to cool.

5. Why do the Thermo 1300/1310 and 1600/1610 GCs and PerkinElmer 590/690 and GC2400 GCs use the same Hot Swap column nut as Agilent GCs?

The threads on the reducing nut that connects to the inlet body (weldment) are the same for all these GCs. This means that Restek reducing nuts for Agilent GCs (cat.# 22078) can be installed in Thermo and PerkinElmer GCs, which then allows you to use the Hot Swap column nut, ferrule, and inlet seal combination that we recommend for Agilent split/splitless inlets.

6. Which Hot Swap column nut should I use with my Shimadzu instrument?

This will depend on the type of inlet adaptor that you have installed in you instrument. For original Shimadzu inlet adaptors, use Hot Swap finger-tight fittings for Shimadzu GCs. For Restek inlet adaptors (cat.# 27222 and 27223), use Hot Swap column nuts for 1/16” fittings.