AY McDonald Insulated Corporation Stops

AY McDonald Insulated Corporation Stops

A.Y. McDonald Insulated Corporation Stops: Defending Against Electrical Currents

Stray electrical currents can be present in water service lines and may cause issues in the metallic piping systems, including shock hazards for field personnel and accelerated corrosion of water distribution system components. This can even occur on service lines located on the water service lateral.

The corporation (corp) stop is an important part of the water service lateral and is considered the initial control valve of the service line. The sole purpose of a corporation stop is to allow for the installation of a new water service line without interrupting the water main pressure. As a special stop valve that is installed into the water main, the corporation stop is usually used only once. However, it may be utilized again in the instance that water needs to be shut off deep below the ground for one reason or another.


A.Y. McDonald’s new insulated corporation stop addresses stray electrical currents that can occur at the water service lateral. This solution provides the following features:

  • Nylon insulator has high dielectric, high compressive and impact strength
  • EPDM O-ring in nylon endpiece with tabs to prevent O-ring from falling out
  • Convenience of a union and an insulator in one product. A similar A.Y. McDonald union and insulator has been proven and used in the natural gas industry for years.
  • Robust No-Lead Brass that conforms to ASTM B584, UNS C89833 (latest revision)
  • Manufactured in compliance with ANSI/AWWA C800 (latest revision)
  • PTFE coated brass ball rotates 360-degrees
  • Valve rated for 300 PSIG water pressure, end connections not to exceed rated pipe pressures
  • Blowout proof EPDM port seals
  • End piece joint sealed with an EPDM O-ring and thread locker

Insulated products are a simple, cost-effective way to fight stray currents and the problems associated with them in metallic service lines and mains either in new or existing lines. They help utilities to insulate their systems with a minimum of change to existing service line materials, specifications, and installation procedures – saving both time and money.


For more information about the A.Y. McDonald insulated corporation stops, call Customer Service at 1-800-292-2737 or visit aymcdonald.com.