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Large diameter sewer connections
Large Diameter Couplings
A proven solution pros have relied on for decades to connect, repair and rehabilitate large diameter sewer pipe. Engineered around the measured outside diameters of your pipes, for connections standard sizes don’t cover.
Proven for decades
Engineered to your O.D.s
Non-shielded or Strong Back RC
No minimum order
What they’re for
When a catalog size won’t fit
Large diameter work doesn’t always line up with a catalog size. When a connection falls outside our standard line, our team can engineer a coupling around the measured outside diameter of each pipe, for repairs, alterations and rehabilitation of large diameter sewer pipe.
Custom
Built to your O.D.s
Engineered around the measured outside diameter of each pipe.
10″ wide
Dependable sealing
A wide flexible PVC body with high torque stainless steel clamps, tightened up to 120 in-lb.
6 types
Versatile connections
Clay, concrete, cast iron, ductile iron, plastic or fiberglass, with a bushing system for O.D. differences from 1¼″ to 12″.
2 versions
Shielded or not
Available non-shielded, or as a Strong Back RC shielded coupling with a stainless steel shield.
Check the standard line first
Our standard couplings run up to 27″ nominal, for pipe up to about 33.9″ O.D., and our Strong Back HTRC corrugated pipe couplings run up to 60″. If your connection fits one of those, start there. If it doesn’t, reach out to our team about a custom coupling.
Standard Couplings finder › Strong Back HTRC corrugated couplings ›
Versions
Non-shielded or Strong Back RC shielded
The non-shielded coupling is the right fit for many jobs. Where burial depth, soil conditions or the project spec call for added support against earth loads, settlement and shear, the Strong Back RC stainless steel shield wraps the coupling and helps keep the pipe in line against shear forces from soil compaction, shifting and settling.
- Non-shielded. Flexible PVC with high torque stainless steel clamps, for connections without heavy earth loads.
- Strong Back RC shielded. The stainless steel shield helps keep the pipe in line against shear forces from soil compaction, shifting and settling.
Conditions vary by region and job. Always follow the project specifications and your local codes and regulations when choosing between the two.
Non-shielded
The flexible PVC Large Diameter Coupling with high torque stainless steel clamps. Coupling clamps tighten to 120 in-lb.
Strong Back RC shielded
The same coupling with a stainless steel shield over the joint for added strength and support. Shield clamps tighten to 60 in-lb.
Custom builds
Made to the job’s numbers
A coupling we built to a job’s measured outside diameters, shown as a dimensional drawing and as an example of the submittal that goes with it.
Example submittal
Two pages for the same 44.00″ × 38.30″ build: product data, materials, installation summary, review block and the dimensional drawing
How to order
Your measurements. Our engineering.
01
Measure both pipes
Get the outside diameter of each pipe. On large pipe, wrap a tape around it and divide the circumference by 3.1416.
02
Share the details
Send both O.D.s, the material of each pipe and the application.
03
Our team reviews it
We review the connection and follow up on a custom coupling, and any reducer bushings, for your job. No minimum order.
Custom parts are non-refundable, so measure carefully.
Installation
How it goes together
1
Reducer on the small pipe
Install the reducer bushing near the end of the small pipe, with the single lip away from the pipe end.
2
Coupling over the reducer
Slide the coupling over the reducer and snug the clamps to hold it in place.
3
Insert the large pipe
Push the large pipe into the other end of the coupling.
4
Tighten and inspect
Tighten the coupling clamps to 120 in-lb, and any shield clamps to 60 in-lb. Bed and support the pipe, then inspect and test before backfilling.
Couplings with two reducer bushings have their own install sheet, in Documents below.
Specifications.
| Sizes | Engineered to the measured O.D. of each pipe |
| Part numbers | LDC followed by the pipe O.D.s, for example LDC 44.00x38.30 |
| Pipe materials | Clay, concrete, cast and ductile iron, plastic or fiberglass |
| Versions | Non-shielded, or Strong Back RC with a stainless steel shield |
| Body | Flexible PVC, 10″ wide |
| Clamps | High torque stainless steel with multiple take-up points |
| Installation torque | 120 in-lb on the coupling clamps. 60 in-lb on shield clamps, if supplied. |
| Reducer bushings | For O.D. differences from 1¼″ to 12″ |
| Maximum operating temperature | 140°F, non-continuous |
| Minimum operating temperature | −30°F |
| Standard | ASTM D5926 |
| Ordering | No minimum order. Custom parts are non-refundable. |
Documents.
Installation instructions, an example submittal, custom build drawings and the catalog page.
All part numbers
2 Large Diameter parts
Open any part for its specs, dimensional drawing and documents.
No part number matches.
LDC 1
LDCX 1
Got questions?
Whether it’s sizing, an odd fitting or a tricky tie-in, our team can help. Reach out, or find your Fernco rep.