U.S. Pipe does not recommend the use of a FIELD LOK® Gaskets with a TYTON® Plugs. Due to the fact that you cannot get the gasket out unless you cut the pipe bell off because of the flange on the end of the plug. If the plug is pushed in too deep then the set screw holes can be in the gasket bulb causing it to leak. Since the installation was performed with a FIELD LOK Gasket, you cannot pull it out and the fitting or pipe bell would have to be scrapped.

U.S. Pipe's primary method of thrust restraint are restrained joints.

A column of liquid moving through a pipeline has momentum or force that tends to separate the joints at changes in direction (bends and tees), stops (plugs, caps, or closed valves), and changes in size (reducers). Some means must be used to prevent joint separation to maintain the integrity of the pipeline. Three such means are thrust blocks, tie rods, and restrained joints.

Thrust blocks are usually poured-in-place concrete.  They must be engineered with full knowledge of the pipeline operating characteristics and of soil type and bearing strength. They must bear against virgin soil, because thrust forces in the pipeline are transmitted through the thrust block to the soil.  Depending on these conditions, thrust blocks can be quite massive. The use of thrust blocks can delay completion of the project to allow the concrete to cure adequately before applying test pressure to the pipeline. If future construction disturbs the thrust block or the surrounding soil, joint restraint and the integrity of the pipeline can be jeopardized.

Tie rods usually involve some sort of fabricated steel harness on either side of the joint held together by tie-rods. This type of joint restraint is generally labor intensive. A tie-rod type of joint restraint must be adequately protected against weakening by corrosion, or else the joint restraint and integrity of the pipeline can be jeopardized.

Restrained joints are designed to hold the joint together against a rated pressure while the pipeline transfers the thrust force to the surrounding soil envelope. In order to calculate the footage of restrained pipeline necessary for the thrust force to be fully dissipated to the soil, it is necessary to know pipe diameter, maximum anticipated internal pressure, depth of cover, soil type, and trench construction type, as well as the configuration (e.g., bend angle) requiring restraint. The calculated restrained footage must be installed on each side of the fitting. Since polyethylene encasement for external corrosion protection reduces the friction between the pipeline and the surrounding soil, the calculated restrained footage is usually multiplied by a factor of 1.5 for pipelines where polyethylene encasement is to be installed.

Mechanical joint retainer glands, both common and proprietary design, are available for use where such devices must be used (e.g., a special valve or meter). However, U.S. Pipe does not recommend their use. Restrained push-on joints manufactured by U.S. Pipe are less susceptible to external corrosion, offer appreciably more deflection, and are much less labor-intensive to install.

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UL and FM Listings

No. It's always a good practice to use the lubricant furnished by the manufacturer. Our lubricant is formulated to be nontoxic, does not support bacterial growth, has no deteriorating effects on the gasket material, and is water soluble so it readily flushes away prior to acceptance testing of the pipeline. It doesn't impart any taste or odor to the water in the pipeline, and meets the requirements of AWWA/ANSI C111/A21.11.

Because it is water soluble, it's sometimes difficult to maintain lubrication on wet surfaces such as a wet trench or stream crossing. In these conditions, it's advisable to apply the lubricant liberally – as much as three times as much as would normally be used.

We do not recommend the use of spray-on lubricants.

AWWA/ANSI C110/A21.10: Ductile Iron and Gray Iron Fittings, 3 in. through 48 in. For Water and Other Liquids

AWWA/ANSI C153/A21.53: Ductile Iron Compact Fittings, 3 in. through 24 in. and 54 in. through 64 in. for Water Service

AWWA/ANSI C111/A21.11: Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings

AWWA/ANSI C104/A21.4: Cement-Mortar Lining for Ductile-Iron Pipe and Fittings for Water

AWWA/ANSI C116/A21.16: Protective Fusion Bonded Epoxy Coatings for the Interior and Exterior Surfaces of Ductile-Iron and Gray-Iron Fittings for Water Supply Service

AWWA/ANSI C105/A21.5: Polyethylene Encasement for Ductile-Iron Pipe Systems

AWWA/ANSI C600: Installation of Ductile-Iron Water Mains and their Appurtenances

Cast iron is a generic name for any high carbon molten iron poured as a casting. When used to refer to pipe, cast iron (sometimes called gray iron) is a specific type in which the free graphite (Carbon) is in the shape of flakes. Cast Iron pipe were introduced into the United States in 1817.

Ductile Iron is a specific type of cast iron in which the free graphite is in the shape of nodules or spheroids. (Other names for ductile iron are nodular iron or spheroidal graphite iron.) Ductile Iron Pipe were introduced to the market in 1955.

Although nearly identical chemically, the two irons are quite different metallurgically. The now obsolete standard for Cast Iron Pipe (ANSI/AWWA A21.6/C106) required an iron strength of 18/40 (18,000 psi Bursting Tensile Resistance and 40,000 psi Ring Modulus of Rupture.) Although tensile testing was not a requirement of this standard, a tensile test of gray cast iron pipe would give a test result of approximately 20,000 psi Ultimate Tensile Strength, with no measurable Yield Strength or Elongation.

The current standard for Ductile Iron Pipe (ANSI/AWWA A21.51/C151) requires a minimum grade of 60-42-10 (60,000 psi Ultimate Tensile Strength, 42,000 psi Yield Strength, and 10% Elongation.) In addition, Ductile Iron Pipe manufactured under this standard are required to meet a minimum of 7 ft lbs impact resistance by the Charpy test. (Compare Gray Iron Pipe with an impact resistance of approximately 2 ft lbs or less.)

The difference in the physical properties of these two materials is attributable almost entirely to the difference in the shape of the free graphite. The shape of the graphite is determined at the instant of solidification and is made nodular by the addition of magnesium to the molten iron bath. Although Cast Iron was the best engineering material available for pipe production for nearly five hundred years, the development of Ductile Iron Pipe provides a far superior product.

ANSI/AWWA C600 "Installation of Ductile-Iron Water Mains and Their Appurtenances" requires that newly installed Ductile Iron water mains be hydrostatically tested at not less than 1.25 times the working pressure at the highest point along the test section and not less than 1.5 times the working pressure at the lowest point of testing.

After the air has been expelled and the valve or valves segregating the part of the system under test have been closed, pressure is then normally applied with a hand pump, gasoline-powered pump, or fire department pumping equipment for large lines. After the main has been brought up to test pressure, it is held at least two hours and the make-up water measured with a displacement meter or by pumping the water from a vessel of known volume. The make-up water is called the "testing allowance," and the allowable amount is a function of length of pipe tested, nominal diameter of the pipe, and the average test pressure. The hydrostatic pressure test helps to identify damaged or defective pipe, fittings, joints, valves, or hydrants, and also the security of the thrust restraint system.

The "testing allowance" is not a "leakage allowance." Properly installed Ductile Iron pipelines with properly assembled joints are bottle-tight and do not leak. The "testing allowance" is, however, a practical measure used to maintain the pressure, which might actually drop because of factors other than leakage, including trapped air, absorption of water by the cement lining, extension of restrained joints and other small pipe-soil movements, temperature variations during testing, etc.

The ANSI/AWWA C100 series are applicable to Ductile Iron pipe and fittings.  Below is a list of the Standards by title:

Further information may be found in the AWWA Manual M41, Ductile Iron Pipe and Fittings. 

These Standards and Manuals are available from the American Water Works Association, 6666 West Quincy Avenue, Denver, Colorado 80235, Telephone (800) 926-7337, Fax (303) 347-0804, or via e-mail at info@awwa.asn.au.