Smith-Blair · Cast Reducing Coupling
Style 441 OMNI Cast Reducing Coupling
Ductile Iron, Reducing Sizes, Alloy Steel Bolts
250 PSI Max Working Pressure
-20°F to +180°F Temperature
Nitrile (Buna-N) Gasket
Ductile Iron Sleeve and Followers
Low-Alloy Steel Bolts
NSF/ANSI 61 and 372
AWWA C219
2.34-9.85 in Pipe OD
20-35 lb Weight
Description
The Smith-Blair Style 441 OMNI cast reducing coupling joins plain-end pipe of two different nominal sizes — 2-1/2 x 2 in, 6 x 4 in and 8 x 6 in. Cast ductile iron parts take OMNI followers and gaskets sized to each end, so one coupling bridges the size change and the OD difference between pipe types.
Followers are color coded by pipe type — red for iron pipe size OD, blue for ductile iron OD, gray for asbestos cement OD — and gaskets and followers are permanently marked with part number and range. To order, pick the size with the larger end's OD range in the first row, then the smaller end's OD range in the second; the part number shows in the third.
Application: joining plain-end pipe of two different nominal sizes: 2-1/2 x 2, 6 x 4 and 8 x 6 in.
Key Features
- Working pressure up to 250 PSI
- Joins two nominal sizes in one cast coupling
- Four large-end and five small-end OD ranges on the 6 x 4 and 8 x 6 in sizes
- Color-coded, permanently marked followers and gaskets for correct selection
- Certified to NSF/ANSI 61 and NSF/ANSI 372; meets applicable portions of AWWA C219
What Ships and What It Needs to Run
Included: the reducing coupling with two follower flanges, two Nitrile gaskets and the alloy steel bolts with nuts, ready to install.
Pipe stiffeners on HDPE, ordered separately. Smith-Blair requires stiffeners on polyethylene pipe; ask us to quote them with the coupling.
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 250 PSI on every reducing size; for a particular installation the allowable pressure also depends on pipe size and type, pipe condition, service conditions and installation workmanship.
Materials Specifications
| Sleeve |
Ductile iron 65-45-12 or 80-55-06 per ASTM A536, ends with a smooth inside taper for uniform gasket seating |
| Gasket |
Nitrile (Buna-N) per ASTM D2000, certified to NSF/ANSI 61-G; resists water, acids, alkalies and most (aliphatic) hydrocarbons |
| Follower flanges |
Ductile iron 65-45-12 per ASTM A536, color coded by pipe type and marked with part number and range |
| Bolts and nuts |
High-strength low-alloy (HSLA) steel per AWWA C111/A21.11: 5/8-11 UNC track-head oval-neck bolts, heavy hex semi-finished nuts |
| Finish |
Flexi-Coat fusion-bonded epoxy, meets AWWA C213 |
Materials subject to change by the manufacturer.
Pipe Applications
Steel, stainless steel, cast and ductile iron, asbestos cement and PVC. HDPE takes pipe stiffeners, which Smith-Blair requires on polyethylene pipe. For other pipe materials, email us and we confirm the fit with Smith-Blair engineering.
Sizes
| Nominal size - End 1 OD |
End 2 OD |
| 2-1/2 x 2 in - 2.65-2.88 in OD |
2.34-2.63 in |
| 6 x 4 in - 6.28-6.63 in OD |
4.00-4.15, 4.22-4.50, 4.46-4.86, 4.80-5.10, 5.11-5.45 in |
| 6 x 4 in - 6.56-6.96 in OD |
4.00-4.15, 4.22-4.50, 4.46-4.86, 4.80-5.10, 5.11-5.45 in |
| 6 x 4 in - 6.90-7.22 in OD |
4.00-4.15, 4.22-4.50, 4.46-4.86, 4.80-5.10, 5.11-5.45 in |
| 6 x 4 in - 7.25-7.65 in OD |
4.00-4.15, 4.22-4.50, 4.46-4.86, 4.80-5.10, 5.11-5.45 in |
| 8 x 6 in - 8.40-8.63 in OD |
6.00-6.15, 6.28-6.63, 6.56-6.96, 6.90-7.22, 7.25-7.65 in |
| 8 x 6 in - 8.54-9.11 in OD |
6.00-6.15, 6.28-6.63, 6.56-6.96, 6.90-7.22, 7.25-7.65 in |
| 8 x 6 in - 9.05-9.45 in OD |
6.00-6.15, 6.28-6.63, 6.56-6.96, 6.90-7.22, 7.25-7.65 in |
| 8 x 6 in - 9.46-9.85 in OD |
6.00-6.15, 6.28-6.63, 6.56-6.96, 6.90-7.22, 7.25-7.65 in |
Choose the size in the first option; the part number shows in the last option.
Bolts and Laying Length
| Size |
Laying length |
5/8 in bolts |
| 2-1/2 x 2 in |
8-1/2 in |
2, 8 in long |
| 6 x 4 in |
5 in |
8, 4-1/2 in long |
| 8 x 6 in |
5 in |
10, 4-1/2 in long |
As printed in the Style 441 datasheet reducing table.
Installation Notes
- Most sizes stab fit with no disassembly. Clean the pipe ends, then place a follower and a gasket on each end, beveled gasket edge facing the pipe end.
- Lubricate the pipe and gaskets with a soap-and-water solution that meets the water and pipe supplier's requirements (anti-freeze may be needed).
- Center the coupling over the gap between pipe ends, within the gap in the instructions. Deflection up to 4° per coupling.
- Slide the gaskets against the sleeve and the followers behind them, fit the bolts hand-tight, then tighten gradually, alternating opposite sides so the followers stay parallel, to the torque in the instructions. Recheck torque after the line is pressurized.
- On polyethylene pipe, fit the pipe stiffeners Smith-Blair requires before installing the coupling.
- Anchor the pipe: the coupling seals around it, and Smith-Blair requires proper anchoring to restrain pipe movement and prevent pull-out.
From Smith-Blair Installation Instructions TI-017 (Rev 08/26/21), in the Data Sheet tab.
Before You OrderAll Smith-Blair products are Made to Order and Non-Returnable.
Items typically shipped in 5 - 10 business days.
Other reducing sizes, other gasket materials such as EPDM, stainless hardware and insulating boots are built to order — email sales@watermainsupply.com with both pipe ODs and materials.
