In the water service lateral, a service fitting either connects two pieces of service line together or connects a service line to a valve or other component. A coupling is a type of service fitting that is a sleeve used to join two sections of pipe or tube in a straight line. The Cambridge Coupling brings the versatility of service fittings to another level.


The Cambridge Coupling is a unique fitting with a patented design that provides the installer with a 0.400” range to accommodate varying outside diameter (OD) sized pipes. Additionally, the part will accommodate pipes that are slightly oval or slightly deformed, saving time and materials in different sizing situations. The design features of the Cambridge Coupling include the following:

  • Rated at 300 PSIG
  • AWWA C800 and NSF 61 & 372 compliant
  • The range of each coupling overlaps slightly to cate to different installation scenarios
  • Allows for more than 3/8” range
  • Rated to withstand the same pressures as the tubing they are designed to fit
  • Designed and tested for cold potable water only
  • Rubber gaskets are standard
  • The connection is shipped ready to use. Simply insert the pipe and tighten.


From copper and PEX to polybutylene and PVC, virtually any type of water works pipe materials are acceptable with the Cambridge Coupling. The user should make sure to use the appropriate range or the pipe OD and a stainless-steel insert for all flexible plastic materials. A.Y. McDonald’s Cambridge Coupling product offering includes multiple series options, as noted below:

The parts that make up the Cambridge Coupling are NSF 61 approved for drinking water and meet US Public Law 111-380 (Bill S.3874), as well as NSF 61-G, NSF 372, and state no-lead laws. The body and nut are made of no-lead water works brass (B89833) for strength and durability. The gripper sub-assembly is symmetrical and a snug fit in the nut, preventing loss of the gripper and seals in the trench.


When it comes to maintaining a water service lateral, the ability to keep inventory low while saving on time and money is a win-win situation. That’s where the Cambridge Coupling comes in handy. To learn even more about this product, including installation instructions and the model number format, call A.Y. McDonald’s customer service department at 1-800-277-2737, fill out a contact us form on, or take the ‘Cambridge Coupling’ AYU course.