Smith-Blair 972 Heavy-Duty Restrained Dismantling Joint, Steel Body, AWWA Class D Flanges, 4-72 in

The Smith-Blair Style 972 is a heavy-duty restrained dismantling joint for valve, pump, meter and other flanged fitting installations, 4 to 72 in nominal. A flanged spool telescopes through a flanged adapter sleeve to fit the gap between companion flanges, and all-thread alloy tie rods run through the flange bolt holes to carry the thrust, so no other joint restraint is needed at the valve or pump.

Both ends carry AWWA C207 Class D flanges that bolt to 125/150 lb companion flanges, with a Nitrile gasket sealing on the spool. The joint ships with alloy steel tie rods, nuts and washers; the rod count and size by nominal size are in the table below.

Application: restraining and dismantling valve, pump, meter and other flanged fitting installations, including butterfly valves and pumps that come out of service for maintenance.

Key Features

• Working pressure up to 150 PSI
• Tie rods restrain the joint and the flanged fittings, making other joint restraints unnecessary
• Telescopes to fit varying face-to-face dimensions; no special tools required
• Flange gaskets install without prying apart mated flanges
• Meets applicable portions of AWWA C219; the Smith-Blair spec sheet certifies it to NSF/ANSI 61 and NSF/ANSI 372

Up to 150 PSI on every size. 4 to 72 in. For a particular installation the allowable pressure also depends on the piping system, service conditions and installation workmanship; other pressures are available from Smith-Blair on request.

Materials subject to change by the manufacturer.

Flanged steel, ductile iron and cast iron pipe, and flanged valves, pumps, meters and fittings.

Choose the size; the part number shows in the last option.

From the Smith-Blair 2025 price book. Rods are alloy steel all-thread and pass through the flange bolt holes.

• Check that the companion flanges match the joint's flanges and are parallel and axially aligned, then clean the flange faces of scale, dirt and debris.
• Remove the all-thread tie rods so the flanged spool moves freely in the adapter, set the joint between the companion flanges (note the flow orientation in the instructions) and bolt each end hand tight with the flange gaskets.
• Lubricate the spool and gasket with a soap-and-water solution that meets the water and pipe supplier's requirements, then slide the gasket and pusher flange into place.
• Torque the end-flange nuts to the job specification, then tighten the follower nuts evenly, alternating sides, to the torque in the instructions; re-torque after the line is pressurized.

From Smith-Blair Installation Instructions TI-033 (Rev 08/27/21), in the Data Sheet tab.