Tubing sleeves for capillaries

For easy minimal dead volume capillary connections

Biotech Fluidics provides a range of different tubing sleeves for connecting various capillary dimensions into standard 10-32 or 6-32 coned port designs, including the MicroTight® and NanoTight™ fitting systems. The sleeves are colour-coded for easy inner diameter identification.

Note that the 1/16” OD sleeves can also be used with the Super Flangeless™ fittings in 1/4-28 flat bottom ports and that the PEEK 1/16” OD sleeves are recommended to use with the SealTight™ fittings when connecting to 10-32 coned ports.

Tubing sleeves in FEP materials are generally rated for lower pressures than PEEK tubing sleeves, but in return they do require less torque to seal, making finger tightening sufficient in most cases. The PEEK tubing sleeves are normally required when stainless-steel fittings are used, to avoid extensive sealing pressure that could potentially damage of the capillary wall.

How to choose and install sleeves?

First select a sleeve material and outer diameter (OD) that match your fitting system and receiving port, and then find a sleeve inner diameter (ID) that match the OD of your capillary tubing while allowing 0.001”–0.002” (25–50 µm) gap between the capillary and the sleeve. Then, slip the sleeve over your capillary flow path tubing, such that your capillary extends all the way through the sleeve, but not beyond the end of the sleeve. Pick the correct fitting that corresponds with your receiving port, slide it over the sleeved capillary and connect as normal.

Why use tubing sleeves?

Because most capillary tubing connections are made into coned receiving ports, where the port is not designed to be used with capillary tubing directly, special care must be used to ensure a good connection. While custom ferrules can help make these connections, they only offer a fixed-length nose — and because most tubing pockets will vary slightly in length, this can lead to leaking or dead volume.

To help save overall expense while maintaining a concentric connection with minimal dead volume, Biotech Fluidics recommends the use of IDEX tubing sleeves. Because sleeves are not permanently attached to a ferrule, they can easily adapt to varying tubing pocket depths. Additionally, because they are manufactured using extruded polymer tubing, you are assured of the concentricity of the resultant connection.

Product details

MicroTight® tubing sleeves (0.025” OD PEEK)

  • Manufactured from PEEK polymer
  • Pressure rated to 4,000 psi (276 bar)
  • Connected using the F-172 MicroFerrule together with P-416BLK MicroTight® female nut to 5/16-24 coned ports

IDEX Health & Science MicroTight® tubing sleeves feature an outer diameter of 0.025” and offer a wide assortment of inner diameters to help facilitate capillary tubing connections with the MicroTight® accessories. Because the sleeves are manufactured from PEEK polymer, they carry an upper temperature threshold of 125 ºC.

Part No.*ODIDFor Capillary SizeColourMaterialPressure Rating
F-1800.025"125 µm (0.005”)70–110 µmRedPEEK4,000 psi (276 bar)
F-1810.025"180 µm (0.007”)125–165 µmYellowPEEK4,000 psi (276 bar)
F-1820.025"230 µm (0.009”)175–215 µmNaturalPEEK4,000 psi (276 bar)
F-1830.025"280 µm (0.011”)225–265 µmBluePEEK4,000 psi (276 bar)
F-1840.025"330 µm (0.013”)275–315 µmOrangePEEK4,000 psi (276 bar)
F-1850.025"395 µm (0.0155”)340–380 µmGreenPEEK4,000 psi (276 bar)
F-1860.025"455 µm (0.018”)400–440 µmBlackPEEK4,000 psi (276 bar)
F-1870.025"535 µm (0.021”)480–520 µmNaturalPEEK4,000 psi (276 bar)
F-1880.025"152 µm (0.006”)95–135 µmPurplePEEK4,000 psi (276 bar)
Part No.*DescriptionContent
1328MicroTight Tubing Sleeve KitContains (6) each of the sleeve sizes listed above (F-180–F-188)
1356MicroTight Connector KitContains: a 10-pack of each MicroTight Tubing Sleeve (F-180–F-187); (2) P-770 MicroTight Adapters; and (2) MicroTight P-720 Unions

NanoTight™ tubing sleeves (1/16” OD FEP)

  • Manufactured from FEP fluoropolymer
  • Pressure rated to 4,000 psi (276 bar)
  • For use with fingertight fittings
  • Not recommended for stainless-steel fittings

NanoTight™ tubing sleeves are manufactured using FEP fluoropolymer and precisely cut to a 1.6” length. A wide assortment of sleeves is available, ensuring the availability of a NanoTight™ sleeve for most applications. Many of the sleeves feature a light colour tint that can help more easily identify the inner diameter for future orders. Because FEP is the base polymer for these sleeves, there is a maximum recommended continuous operating temperature of 50 ºC.

The NanoTight™ sleeves were designed primarily for use with the NanoTight™ fittings and also work well with the Super Flangeless™ fittings for connecting 1/16” OD tubing to flat bottom ports. For connections that will be used with stainless steel fittings or at higher temperatures, we recommend using the PEEK tubing sleeves, found below.

Part No.*ODIDFor Capillary SizeColourMaterialPressure Rating
F-2371/16"125 µm (0.005”)70–110 µmRedFEP4,000 psi (276 bar)
F-2381/16"180 µm (0.007”)125–165 µmYellowFEP4,000 psi (276 bar)
F-2391/16"215 µm (0.0085”)160–200 µmNaturalFEP4,000 psi (276 bar)
F-2401/16"280 µm (0.011”)225–265 µmBlueFEP4,000 psi (276 bar)
F-2411/16"330 µm (0.013”)275–315 µmOrangeFEP4,000 psi (276 bar)
F-2421/16"395 µm (0.0155”)340–380 µmGreenFEP4,000 psi (276 bar)
F-2431/16"455 µm (0.018”)400–440 µmBlackFEP4,000 psi (276 bar)
F-2441/16"535 µm (0.021”)480–520 µmNaturalFEP4,000 psi (276 bar)
F-2451/16"610 µm (0.024”)555–595 µmRedFEP4,000 psi (276 bar)
F-2461/16"685 µm (0.027”)630–670 µmYellowFEP4,000 psi (276 bar)
F-2471/16"840 µm (0.033”)785–825 µmGreenFEP4,000 psi (276 bar)
F-2521/16"1.07 mm (0.042”)1 mmPurpleFEP4,000 psi (276 bar)

1/16” OD PEEK tubing sleeves

  • For connecting capillary tubing to standard 10-32 ports
  • Pressure rated to 6,000 psi (414 bar)
  • Must be used with wrench tightened nuts
  • Required when using stainless steel fittings

Like the NanoTight™ FEP sleeves above, these PEEK tubing sleeves are designed to be used with 1/16” OD, 10-32 threaded fittings to adapt capillary tubing to standard coned ports. Made of PEEK polymer, these 1.3” long sleeves can be used up to 125 °C and 6,000 psi (414 bar).

These sleeves require a wrench tightened nut to achieve proper sealing and we recommend the F-193 SealTight™ fitting with F-192 slotted dual-grip ferrule. Many researchers also use a stainless-steel nut and ferrule with these sleeves, such as the U-400 and U-401.

Part No.*ODIDFor Capillary SizeColourMaterialPressure Rating
F-2251/16"125 µm (0.005”)70–110 µmRedPEEK6,000 psi (414 bar)
F-2261/16"180 µm (0.007”)125–165 µmYellowPEEK6,000 psi (414 bar)
F-2271/16"230 µm (0.009”)175–215 µmYellowPEEK6,000 psi (414 bar)
F-2281/16"280 µm (0.011”)225–265 µmBluePEEK6,000 psi (414 bar)
F-2291/16"330 µm (0.013”)275–315 µmNaturalPEEK6,000 psi (414 bar)
F-2301/16"405 µm (0.016”)340–380 µmOrangePEEK6,000 psi (414 bar)
F-2311/16"560 µm (0.022”)505–545 µmNaturalPEEK6,000 psi (414 bar)
F-2321/16"785 µm (0.031”)730–770 µmNaturalPEEK6,000 psi (414 bar)
F-2331/16"865 µm (0.034”)785–825 µmBluePEEK6,000 psi (414 bar)
F-2341/16"685 µm (0.027”)630–670 µmYellowPEEK6,000 psi (414 bar)

1/32” OD FEP tubing sleeves

These 1.6” long sleeves facilitate connecting capillary tubing into ports designed for 1/32” OD tubing. Please refer to the product listing below to select the appropriate sleeve for your capillary OD size. These sleeves can be used at up to 50 ºC and have a pressure rating of 1,750 psi (121 bar).

Recommended fittings to use with the 1/32” OD FEP sleeves:

  • The F-113 ferrule with any two-piece fingertight nut for 10-32 ports
  • The F-126S MicroTight® fitting for 6-32 coned ports

Part No.*ODIDFor Capillary SizeColourMaterialPressure Rating
F-3741/32"280 µm (0.011”)225–265 µmBlueFEP1,750 psi (121 bar)
F-3751/32"330 µm (0.013”)275–315 µmGreenFEP1,750 psi (121 bar)
F-3761/32"395 μm (0.0155”)340–380 µmOrangeFEP1,750 psi (121 bar)

1/32” OD PEEK tubing sleeves

These 1.6” long 1/32” OD PEEK tubing sleeves can be used with any fitting designed for 1/32” OD tubing when smaller tubing must be connected. Select the appropriate sleeve from the product listing for your capillary tubing OD size. The 1/32” OD PEEK tubing sleeves have a maximum recommended temperature of 125 ºC and have a pressure rating of 5,000 psi (345 bar).

Recommended fittings to use with the 1/32” OD PEEK sleeves:

  • The F-113 ferrule with any two-piece fingertight nut for 10-32 ports
  • The F-126S MicroTight® fitting for 6-32 coned ports
  • The F-112 MicroFerrule with P-416BLK MicroTight® female nut

Part No.*ODIDFor Capillary SizeColourMaterialPressure Rating
F-3811/32"180 µm (0.007”)125–165 µmYellowPEEK5,000 psi (345 bar)
F-3821/32"205 µm (0.008”)150–190 µmNaturalPEEK5,000 psi (345 bar)
F-3841/32"255 µm (0.010”)200–240 µmBluePEEK5,000 psi (345 bar)
F-3851/32"380 µm (0.015”)325–365 µmNaturalPEEK5,000 psi (345 bar)
F-3861/32"510 µm (0.020”)455–495 µmOrangePEEK5,000 psi (345 bar)
F-3871/32"250 µm (0.011”)225–265 µmRedPEEK5,000 psi (345 bar)
F-3881/32"330 µm (0.013”)275–315 µmBlackPEEK5,000 psi (345 bar)

Resources

Consult the Periodic Table of Analytical Fittings for a quick overview, the Fittings 101 for guidance and learning, and the IDEX Catalogue for product details, or contact Biotech Fluidics for expert advice.

Periodic table of
analytical fittings

Fittings 101
guide booklet

Complete IDEX
catalogue

Any questions?

If you have any inquiries about our products and services, we’re here to help.

Phone: +46 300 56 91 80
Email: info@biotechfluidics.com