Ductile Iron Pipe Icon
Restrained Joint Pipe

Lok-Ring Joint Pipe

The AMERICAN Lok-Ring joint is a restrained joint that utilizes the sealing features of the time-proven AMERICAN Fastite joint. It is an essentially boltless, flexible restrained connection that provides an easily assembled positive restraint against endwise separation due to thrust resulting from internal pressure or external forces. Only a minimal amount of time is required to complete the Lok-Ring assembly, or disassembly if necessary.

The patented1 AMERICAN Lok-Ring joint is designed for working pressures up to 250 psi for sizes 60" through 64". If higher pressure ratings are needed, contact AMERICAN. The Lok-Ring joint can be used with any lesser pressure class of ductile iron pipe, with the maximum operating pressure rating of the joint limited in such cases to that of the pipe. An alloy steel welded-on retainer ring and a split lok-ring, assembled behind the retainer ring, provide the means of restraint. The split lok-ring is held “snug” and constricted against the pipe OD for assembly of the AMERICAN Fastite portion of the joint. After the plain end of the pipe is assembled into the Lok-Ring bell, the lok-ring is released, permitting it to expand. The lok-ring is thus securely positioned behind the welded-on retainer ring and in the socket locking groove on the ID of the Lok-Ring bell. This locks the joint.

The lok-ring, welded retainer ring and all parts of the closure-spreader mechanism are all constructed of corrosion-resistant, high-strength, low-alloy (HSLA) steel. This is the same type of steel specified for bolting material per ANSI/AWWA C111/A21.11, and it has been used successfully in several AMERICAN restrained joint constructions for approximately 40 years. The weld is aluminum bronze, and both the weld and ring are cathodic to – and thus protected by – the greater mass of the ductile iron pipe. Welding is performed using welders qualified to produce high-quality, dependable welds.

The AMERICAN Lok-Ring joint utilizes standard Fastite gaskets and lubricant, and, like the Fastite joint, the Lok-Ring joint is designed to permit deflection in order to facilitate installation and accommodate settlement. It is noted that rotation of the lok-ring under great loads helps to distribute the forces substantially around and between the bell and spigot members.

AMERICAN Lok-Ring Pipe is ductile iron, grade 60-42-10, manufactured and tested in accordance with AWWA C151. It is normally furnished standard asphaltic-coated outside and cement-lined inside in accordance with AWWA C104. When specified, other special linings can be furnished. Fittings are available in both bell-bell and bell-plain end configurations for installation versatility and economy.

1.) U.S. Patents 4,428,604 and 4,524,505.

Read More
contact sales

Standard Dimensions

Size (in.)

Working Pressure1 (psi)

Nominal Laying Length2 (ft.)

A Outside Diameter (in.)

B Socket Depth (in.)

C Plain End to Retaining Ring (in.)

F Bell OD3 (in.)

Retainer Ring

Lok-Ring

60

250

20

61.61

10.57

6.38

66.27

3/4″ × 1 1/4"

3/4″ × 1 1/4"

64

250

20

65.67

10.57

6.38

70.45

3/4″ × 1 1/4"

3/4″ × 1 1/4"

1.) Working pressure is the maximum pressure rating of the joint and is based on its capability to resist thrust due to internal pressure. If higher working pressure is required, check with AMERICAN.

2.) Laying length is nominal 20’. Where exact lengths are required, contact AMERICAN. (See minimum laying lengths below.)

3.) Dimensions subject to change at our option. Check with AMERICAN if smaller or exact dimensions are required. Note that the struts may protrude slightly above the bell in one spot; contact AMERICAN if this may be critical to the application.

Minimum Laying Lengths

Size (in.)

Lok-Ring & Lok-Ring End

Lok-Ring End & Lok-Ring End

60

2’-6"

3’-0"

64

2’-6"

3’-0"

Product Line Information

Domestic Certification
Submittals
Pipe Manual
Project Mgt/Customer Service
Standards
Aerial view of iron pipes

Contact Sales

Reach out to our sales team for more product information.
contact sales

Today's Infrastructure Solutions in the U.S. and Around the Globe.

About Us
American Mark