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John Guest® Speedfit® PEX Pipe and Fittings Installation information

John Guest® Speedfit® PEX Pipe and Fittings

Fittings should be kept clean and undamaged before use.

Sizes: 1/2" and 3/4"

Speedfit fittings can be used with:

  • PEX, Copper, and CPVC pipes conforming to ASTM Standards.
  • Speedfit fittings cannot be used on stainless steel pipe.

Standards: Speedfit products are designed and manufactured under a fully integrated system assessed by BSI to BS EN ISO9001. Speedfit PEI fittings and Speedfit PEX pipe are also NSF-14, NSF-61, ASTM F 877, CSA 137.5, and ASSE 1061.

DO NOT USE FOR Gas, fuel oil, or compressed air applications.

Working pressure and temperature


Maximum Pressure

Maximum Temperature


160 psi



100 psi

180° F

Burst Pressure (fittings): With copper or plastic pipe at 68°F, Speedfit fittings used with the copper of Speedfit PEX Pipe will withstand pressures well over normal service conditions.

Insulation: Should comply with applicable standard for copper.

Minimum bend radius (PEX):

Pipe diameter

1/2" CTS

3/4" CTS

Min radius



  • Clip Spacing (in inches): 1% on length between 68°F and 180°F.
  • Flow rates: Comparable with metal systems.
  • Cleaners, inhibitors, and descalents: For advice on the use of additives such as corrosion inhibitors, the additive manufactures should be consulted.
  • Paint and Chemicals: Only use water- or oil-based paint. Do not allow contact with oil-based jointing compounds, cellulose-based paints, paint thinners, paint strippers, solder flux, acid-based descalents, or aggressive cleaning products.
  • Solder Flux: No fluxes of any type should come into contact with Speedfit products. Extreme care should be taken to ensure that no such contact takes place.
  • Chlorine: Speedfit is not suitable for use in systems where the water contains high levels of Chlorine. E.g., swimming pools, fountains, ext.
  • Exposure to light: Speedfit products, when used indoors, are not affected by sunlight. When used outdoors, protect from ultraviolet light by lagging or painting.
  • Pipe clips: Pipe clips should not be fitted any closer than 2.5" from the end of the fitting. Pipe clips should adequately support the pipe to prevent undue stress (side load) on fittings.
  • Pipe Inserts:
  • Plumbing: while not required, John Guest recommends the use of pipe inserts for plastic piping connections with John Guest products in Standard residential Plumbing (hot and cold water) installations.
  • Heating: John Guest requires the use of pipe inserts for plastic pipe connections with John Guest Speedfit products in all Heating installations.
  • Metal Joists: When 'Cabling' plastic pipe through metal joists, ensure rubber grommets are in place to prevent damage to the pipe.
  • Connection to Boilers: A minimum of 36" run of copper pipe must be installed between the boiler and the Speedfit system.
  • Connection to copper pipe: 18" is the minimum distance to make a solder connection on copper pipe inserted into a Speedfit fitting. Ensure that no solder flux comes into contact with the fitting.
  • Concrete and Masonry: Speedfit pipe and fittings can be laid in concrete and masonry, providing they are installed in conduit pipe with access boxes for the fittings. This enables the pipe to expand and provides accessibility for both pipe and fittings. Fittings and pipe should be removable for possible replacement. Insulation is also recommended to protect against heat loss and the effects of frost.
  • Electrical Continuity: If Speedfit is used in an existing metal system, electrical continuity must be reinstated.
  • System testing: To ensure the pipework and fittings have been installed correctly, whether it be on a new or extended system, it is essential that the system is checked and hydraulically wet tested. Testing should be over 30 psi for 10 minutes and 150 psi for 10 minutes. This testing, combined with other relevant checks, should reveal installation problems and is considered good plumbing practice. However, system testing should not be regarded as a substitute for correct installation.
  • System Flushing: As is usual practice for any plumbing installation, flushing of the system before the use of Speedfit is recommended to remove any contaminants/chemical residue from elsewhere in the system.
  • Vermin: Speedfit products will need special protection in vermin-infested areas.

Twist & Lock Fittings

1/2" CTS

3/4" CT

Tube insertion depth



End Caps

1/2" CTS

3/4" CT

Tube insertion depth



Title: John Guest® Speedfit® PEX Pipe and Fittings Installation information
Description: Specifications for John Guest® Speedfit ® PEX Pipe and Fittings
Published: 7/23/2009
Last Edited: 1/18/2023
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The information contained in this article is for general information purposes only. The information is provided by United States Plastic Corp. and while we endeavor to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.

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