Smith-Blair · Restraint Coupling
Style 472 Pipe-Lock Restraint Coupling
Fabricated Steel, PVC x PVC
235 PSI Max Working Pressure
-20°F to +180°F Temperature
SBR MJ Gasket
Epoxy-Coated Steel Sleeve
Ductile Iron Cam-Lock Glands
Low-Alloy Steel Studs
NSF/ANSI 61 and 372
Restrained Joint, 5° Max Deflection
3.50-38.30 in Pipe OD
29-993 lb Weight
Description
The Smith-Blair Style 472 Pipe-Lock is a fabricated steel restraint coupling that joins and restrains plain-end PVC pipe to plain-end PVC pipe. It comes as a complete unit: the restraint is built into each follower gland, where a Cam-Lock gland with multiple single-tooth wedges grips the pipe and an MJ gasket seals each end.
Multi-Seal builds at 4 to 12 in (catalog suffix -243 and -343) take both IPS and ductile iron OD PVC, so one coupling can mix the two. It also serves to replace split or excessively damaged pipe. Sleeve length — 7, 10 or 16 in, depending on size — is chosen in Option 2.
Application: joining and restraining plain-end PVC pipe, 3 to 36 in.
Key Features
- Rated at the pressure rating of the PVC pipe, up to 235 PSI
- Comes as a complete unit — sleeve, restraint glands, gaskets and studs
- Restraint integral to the follower gland, with multiple single-tooth wedges
- Multi-Seal gasket builds mix IPS and ductile iron OD PVC at 4 to 12 in
- Certified to NSF/ANSI 61 and NSF/ANSI 372
What Ships and What It Needs to Run
Included: the complete unit — epoxy-coated steel sleeve with a Cam-Lock restraint gland on each end, MJ gaskets (Multi-Seal on -243/-343 builds; Smith-Blair MJ gaskets at 30 and 36 in), and studs, nuts and washers.
Genuine Smith-Blair equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
12-Month Smith-Blair Warranty
Smith-Blair warrants its products to be free of defects in materials and workmanship for one year from the date of shipment by Smith-Blair. Dated proof of purchase, such as a bill of sale, is required to establish eligibility. Smith-Blair will repair or, at its option, replace a defective product; the product is returned to the factory or warehouse Smith-Blair designates.
Working Pressure
Up to 235 PSI. The 472 is rated at the pressure rating of the PVC pipe it is installed on, set by the pipe's standard and DR, with 150 PSI at 30 in and 125 PSI at 36 in.
| PVC pipe |
Working pressure |
| AWWA C900 DR14, DI OD |
235 PSI |
| AWWA C900 DR18, DI OD |
235 PSI |
| AWWA C900 DR25, DI OD |
165 PSI |
| AWWA C905 DR18, DI OD |
235 PSI |
| AWWA C905 DR25, DI OD |
165 PSI |
| ASTM D2241 SDR17, IPS OD |
235 PSI |
| ASTM D2241 SDR21, IPS OD |
200 PSI |
| ASTM D2241 SDR26, IPS OD |
160 PSI |
Any PVC class: 150 PSI at 30 in, 125 PSI at 36 in. DR14 and SDR17 are shown at the 235 PSI ceiling of the Cam-Lock 120 PVC restraint spec, the lowest figure in the Smith-Blair documents. UL Listed / FM Approved installations: 150 PSI on C900 DR18 PC150, 4-12 in.
Materials Specifications
| Sleeve |
Fabricated carbon steel, ASTM A283 Gr C or carbon steel with 30,000 PSI minimum yield (ASTM A513 or A53 on 3-4 in per the 477 sleeve spec) |
| Sleeve finish |
Flexi-Coat fusion-bonded epoxy |
| Restraint glands |
Cam-Lock 120, ductile iron 65-45-12, ASTM A536 |
| Wedges |
Single-tooth ductile iron 65-45-12, heat treated to RC 45, E-coated and color-coded red for PVC |
| Breakaway nuts |
Carbon steel or cast iron |
| Actuating bolts |
Ductile iron 60-40-18, ASTM A536 |
| Gland finish |
Flexi-Coat fusion-bonded epoxy per AWWA C213; wedges and actuating bolts E-coated epoxy |
| Gasket |
SBR mechanical joint gasket per ANSI/AWWA C111/A21.11, Multi-Seal gasket (4-12 in) or MJ transition gasket for IPS ODs; Smith-Blair MJ gasket at 30 and 36 in |
| Studs and nuts |
High-strength low-alloy steel per AWWA C111/A21.11 and/or ASTM A193 Gr B7, rolled threads |
| Washers |
Carbon steel per ASTM A108, electro-galvanized with dichromate seal per ASTM B633 |
Materials subject to change by the manufacturer.
Pipe Applications
PVC to PVC: AWWA C900 and C905 PVC at ductile iron ODs, and ASTM D2241 PVC at IPS (steel) ODs. Smith-Blair limits PVC applications to SDR 26 or heavier wall.
Sizes
23 sizes from 3.50 to 38.30 in OD — open for the full list
| Pipe size and OD |
Sleeve thk x length |
| 3 in - 3.50 in OD |
0.250 x 7 in |
| 4 in - 4.50 in OD |
0.250 x 7 in |
| 4 in - 4.50-4.80 in OD |
0.250 x 7 in |
| 4 in - 4.80 in OD |
0.250 x 7 in |
| 6 in - 6.63 in OD |
0.250 x 7, 0.250 x 10 in |
| 6 in - 6.63-6.90 in OD |
0.250 x 7, 0.250 x 10 in |
| 6 in - 6.90 in OD |
0.250 x 7, 0.250 x 10 in |
| 8 in - 8.63 in OD |
0.250 x 7, 0.250 x 10 in |
| 8 in - 8.63-9.05 in OD |
0.250 x 7, 0.250 x 10 in |
| 8 in - 9.05 in OD |
0.250 x 7, 0.250 x 10 in |
| 10 in - 10.75 in OD |
0.250 x 7, 0.250 x 10 in |
| 10 in - 10.75-11.10 in OD |
0.250 x 7, 0.250 x 10 in |
| 10 in - 11.10 in OD |
0.250 x 7, 0.250 x 10 in |
| 12 in - 12.75 in OD |
0.250 x 7, 0.250 x 10 in |
| 12 in - 12.75-13.20 in OD |
0.250 x 7, 0.250 x 10 in |
| 12 in - 13.20 in OD |
0.250 x 7, 0.250 x 10 in |
| 14 in - 15.30 in OD |
0.250 x 7, 0.250 x 10 in |
| 16 in - 17.40 in OD |
0.250 x 7, 0.250 x 10 in |
| 18 in - 19.50 in OD |
0.250 x 7, 0.250 x 10 in |
| 20 in - 21.60 in OD |
0.250 x 7, 0.250 x 10 in |
| 24 in - 25.80 in OD |
0.250 x 7, 0.250 x 10 in |
| 30 in - 32.00 in OD |
0.250 x 10, 0.250 x 16 in |
| 36 in - 38.30 in OD |
0.250 x 10, 0.250 x 16 in |
Choose the size in the first option; the part number shows in the last option.
Max Joint Deflection
| Nominal size |
Per gland |
| 3 in |
3° |
| 4 to 12 in |
5° |
| 14 and 16 in |
2° |
| 18 to 24 in |
1.5° |
| 30 in and up |
1° |
Make any deflection after the joint is assembled and before the gland bolts are tightened.
Installation Notes
- Inspect the shipment for transit damage and confirm the correct product before installing.
- Set the pipe gap at 1/2 to 3/4 in for a 7 in sleeve and 1/2 to 1-1/4 in for a 10 in sleeve.
- Assemble each end as a Cam-Lock mechanical joint: clean and lubricate the pipe end and gasket per AWWA C111, gasket taper toward the plain end, gland lip against the gasket; then tighten the gland bolts evenly (bottom, top, sides, then the rest) to the torque in the instructions.
- Use the red wedges on PVC pipe, never black ductile iron wedges. The Cam-Lock 120 is limited to SDR 26 or heavier pipe wall and is not for use on plain-end fittings.
- Set the wedges: hand-tighten the torque-off nuts until every wedge touches the pipe, then turn each nut 1/2 turn in an alternating pattern until all twist off, never more than 1/2 turn on one nut at a time. Do not remove the retaining washer under the torque-off nut.
From Smith-Blair Installation Instructions TI-055 (Rev 4/16/24), in the Data Sheet tab, and Cam-Lock Installation Instructions TI-057.
Before You OrderAll Smith-Blair products are Made to Order and Non-Returnable.
Items typically shipped in 5 - 10 business days.
304 or 316 stainless hardware, other gasket materials and longer sleeves are built to order — email sales@watermainsupply.com with the pipe OD and PVC class.
