706.08 Vitrified Clay Pipe

1. Specification:

706.08 C&MS.

2. Sampling and/or Inspection Requirements:

Qualified Product List (QPL)

Only material that is approved as a Qualified Product may be used. To verify, refer to Qualified Product List (QPL) on the OMM website http://www.dot.state.oh.us/Divisions/ConstructionMgt/Materials/Pages/QPL.aspx

No sample is required.


All QPL pipe shall be inspected after delivery to the project for dimensions or condition. Dimensions shall conform with those in Table 1 - 706.08.(Field)

Pipe may be glazed or unglazed. If a glaze is applied, the glaze shall be a continuously uniform layer that is substantially free of imperfections. Not more than 10% of the inner surface of any pipe barrel may be free of glaze. There shall be no well defined crazing or hairline cracks. Glazing is not required on the outer surface of the pipe at the spigot, for a longitudinal distance equal to the depth of the socket. Glaze may be entirely absent from the inside of the socket.

The end of the pipe shall be square with its longitudinal axis within limits of Table 1 - 706.08.

Perforations are to be circular, 1/4-in. In diameter and cleanly cut. They shall be spaced and arranged as shown in Table 2 - 706.08.


Pipe 3 inches through 18 inches in diameter, maximum dimension 3 inches. Blister not to project more than 1/8 inch above surface of pipe.

Pipe over 18 inches shall have no blister exceeding 2 in./ft. of internal diameter. Blister not to project above surface of pipe more than 1/8 in./ft. of internal diameter.

Fractures and Cracks

Fracture or cracks passing through the barrel or socket are not permitted.

Chips or fractures on the interior of the pipe shall not exceed 2 in. in length, 1 in. in width, nor a depth 1/4 the thickness of the barrel. Exceptions - a single crack at the spigot end not exceeding 75 percent of the depth of the socket; a single fracture in the socket not exceeding 3 in. around the circumference nor 2 in. lengthwise.

Each length of pipe shall have indented on the exterior the following information:

The initials or name of the manufacturer.

Where applicable, the words "Extra-Strength" or symbol "ES" to identify the extra strength class.

Pipe not meeting the above requirements may be rejected.

3. Method of Test:


ASTM C 301

4. Addendum:TABLE 1

Variations permitted in Dimensions

Nominal Size, in. Laying Length Limit of Minus Variation, in./ft Difference in Length of Two Opposite Sides Max. in. Limit of Minus Variations in Average Inside Diameter in.
3 1/4 5/16 3/16
4 1/4 5/16 3/16
6 1/4 3/8 1/4
8 1/4 7/16 5/16
10 1/4 7/16 3/8
12 1/4 7/16 7/16
15 1/4 1/2 9/16
18 1/4 1/2 11/16
21 1/4 9/16 13/16
24 3/8 9/16 15/16
27 3/8 5/8 1 1/16
30 3/8 5/8 1 3/16
33 3/8 5/8 1 8/16
36 3/8 11/16 1 7/16
39 3/8 3/4 1 7/16
42 3/8 7/8 1 7/16

Average inside diameter shall not vary from a true circle by more than 3% of its nominal diameter measured by taking any two dia meters at 90 degrees from each other and averaging.


Nominal Pipe Size, in. Rows of Perforations
4 4
6 4
8 4
10 6
12 6
15 6
18 8
21 8
24 8

Row spacing approximately 3 in. c/c parallel to the longitudinal axis of the pipe. Rows to be arranged in two equal groups on each side of the vertical center line of the pipe. Lowermost rows shall be separated by an arc of 90 degrees measured across the bottom of the pipe.

Upper most rows of holes shall be separated by an arc of 200 degrees measured across the top of the pipe. Spigot end of bell and spigot pipe shall not be perforated for a distance equal to the depth of the socket.