John Guest products require no special tools. Simply cut the tube square and insert it into the fitting to effect a secure and reliable connection. These products offer the most reliable and cost effective solution to tubing connections. Easily connects to any 3/8" NPT female thread like in our Digiflow meter and accepts the standard 1/4" OD tubing used in the under sink filter systems. Assembles in minutes with simple tools.

• Manufacturer's part number CI010823W 1/4 x 3/8
• Water pressure limit at +68°F = 145 PSIG
• NOT suitable for compressed air and vacuum applications.
  Tube Types
  
  • Plastic Tube - Polyethylene, nylon and polyurethane of the proper size. For soft tubing or thin wall tube we recommend the use of tube inserts.
  • Braided Tube - Use of Tube to Hose Stems is essential when using braided tube. Use of clamps to retain braided tube on barb is recommended.
  • Metal Tube (soft) - Brass, copper or mild steel conforming to the tolerances below.
  • Metal Tube (hard) - Use of Super Speedfit fittings for hard metal tubes or chromium plated tube is NOT recommended.
  • It is essential that outside diameters be free from score marks and that the tube be deburred before inserting the fitting.
• These fittings are produced in Food and Drug Administration (FDA) approved materials and are therefore recommended for food quality applications.

• Fittings and tube should be kept clean and undamaged before use.
  
• All tube and fittings installations must be pressure tested after installation to ensure system integrity before final use. See also 
• How to make a connection.
  
• Do not overtighten plastic threaded fittings as this could cause undue stress and eventual failure. Teflon tape may be required on threads, examine for leaks and determine if tape is needed.