Critical grade sewer connections

Eccentric Couplings

Connect sewer pipes with different outside diameters and keep the inside walls lined up, for a continuous flowline where the grade is critical.

 
1½″ to 15″ 75 parts Clay, concrete, iron, plastic and steel AIS and BABA compliant
 
What they’re for

Keep the flowline continuous.

A standard reducing coupling lines up the centers of the two pipes, which leaves a step along the bottom of the line where the smaller pipe meets the larger one. An eccentric coupling offsets the smaller pipe so the inside walls line up and flow isn’t obstructed.

Fernco eccentric coupling compared with a concentric reducing coupling Two pipe cross-sections with circular enlargements. On the left, aligned clay and PVC pipe inverts provide uninterrupted water flow. On the right, a concentric reducing coupling leaves a step at the transition where debris collects and obstructs flow. Uninterrupted flow Offset pipe transition creating an obstructed flow Clay Pipe PVC Pipe Concentric Coupling FERNCO’S ECCENTRIC COUPLINGS Concentric Reducing Coupling
Fernco eccentric coupling compared with a concentric reducing coupling Two pipe cross-sections with circular enlargements. On the left, aligned clay and PVC pipe inverts provide uninterrupted water flow. On the right, a concentric reducing coupling leaves a step at the transition where debris collects and obstructs flow. Uninterrupted flow Offset pipe transition creating an obstructed flow Clay Pipe PVC Pipe Concentric Coupling FERNCO’S ECCENTRIC COUPLINGS Concentric Reducing Coupling Fernco eccentric coupling compared with a concentric reducing coupling Two pipe cross-sections with circular enlargements. On the left, aligned clay and PVC pipe inverts provide uninterrupted water flow. On the right, a concentric reducing coupling leaves a step at the transition where debris collects and obstructs flow. Uninterrupted flow Offset pipe transition creating an obstructed flow Clay Pipe PVC Pipe Concentric Coupling FERNCO’S ECCENTRIC COUPLINGS Concentric Reducing Coupling
  • Aligned inside wall. The two pipes line up along the bottom for an obstruction-free flow.
  • Coupling and bushing. Most sizes are a two-piece coupling and insert bushing combination. The 1002-64EC is a one-piece eccentric coupling.
  • All common sewer pipe. Clay, concrete, ductile iron, cast iron, plastic and steel.
Fernco eccentric coupling with offset bore
Sizes

Find your size.

Choose the material and size of each pipe. Add the measured outside diameters to confirm the fit. Or browse every part by series below.

First pipe
in
Second pipe
in

No calipers? Wrap a tape around the pipe and divide by 3.14.

Choose both pipes, and matching part numbers show here.

All eccentric parts by series

1001 series Clay to clay4 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1001-64EB6″ clay to 4″ clay7.00–7.75″4.90–5.25″
1001-86EB8″ clay to 6″ clay9.20–9.85″6.90–7.40″
1001-10-8EB10″ clay to 8″ clay12.00–12.70″9.25–9.80″
1001-1512EB15″ clay to 12″ clay17.00–18.65″13.90–14.45″
1002 series Clay to cast iron, plastic or steel18 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1002-43EB4″ clay to 3″ CI, plastic or steel4.85–5.55″3.30–3.55″
1002-44EB4″ clay to 4″ CI, plastic or steel4.75–5.40″3.95–4.55″
1002-46EB4″ clay to 6″ CI, plastic or steel4.90–5.25″6.30–6.80″
1002-54EB5″ clay to 4″ CI, plastic or steel6.30–6.80″4.15–4.60″
1002-55EB5″ clay to 5″ CI, plastic or steel6.30–6.80″5.20–5.65″
1002-64WCEB6″ clay to 4″ CI, plastic or steel (WC)7.50–8.25″4.20–4.55″
1002-65EB6″ clay to 5″ CI, plastic or steel7.00–7.75″5.30–5.70″
1002-66EB6″ clay to 6″ CI, plastic or steel7.05–7.75″6.25–6.80″
1002-84EB8″ clay to 4″ CI, plastic or steel9.25–9.80″4.15–4.60″
1002-86EB8″ clay to 6″ CI, plastic or steel9.25–9.80″6.50–6.75″
1002-88EB8″ clay to 8″ CI, plastic or steel9.25–9.75″8.30–8.85″
1002-10-8EB10″ clay to 8″ CI, plastic or steel12.00–12.70″8.30–8.85″
1002-1010EB10″ clay to 10″ CI, plastic or steel12.00–12.70″10.25–10.75″
1002-1210EB12″ clay to 10″ CI, plastic or steel13.75–14.70″10.15–10.75″
1002-1212EB12″ clay to 12″ CI, plastic or steel13.75–14.70″11.95–12.75″
1002-1512EB15″ clay to 12″ CI, plastic or steel17.00–18.65″12.10–12.70″
1002-1515EB15″ clay to 15″ CI, plastic or steel17.00–18.65″15.00–15.55″
1002-64EC6″ clay to 4″ CI, plastic or steel6.90–7.85″3.95–4.69″
1003 series Clay to ductile iron4 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1003-64EB6″ clay to 4″ ductile iron7.00–7.75″4.70–5.20″
1003-10-8EB10″ clay to 8″ ductile iron12.00–12.70″8.85–9.20″
1003-1510EB15″ clay to 10″ ductile iron17.00–18.65″10.85–11.30″
1003-1512EB15″ clay to 12″ ductile iron17.00–18.65″13.00–13.40″
1004 series Concrete to concrete1 part
PartConnectsFirst pipe O.D.Second pipe O.D.
1004-1210EB12″ concrete to 10″ concrete14.50–15.45″11.70–12.65″
1005 series Concrete to clay2 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1005-64EB6″ concrete to 4″ clay7.30–7.90″4.65–5.10″
1005-1210EB12″ concrete to 10″ clay14.50–15.45″11.70–12.65″
1006 series Concrete to cast iron, plastic or steel12 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1006-44EB4″ concrete to 4″ CI, plastic or steel5.40–5.85″4.05–4.60″
1006-64EB6″ concrete to 4″ CI, plastic or steel7.30–7.90″4.15–4.60″
1006-65EB6″ concrete to 5″ CI, plastic or steel7.30–7.90″5.20–5.80″
1006-66EB6″ concrete to 6″ CI, plastic or steel7.30–7.90″6.50–6.75″
1006-84EB8″ concrete to 4″ CI, plastic or steel9.90–10.65″4.40–4.55″
1006-86EB8″ concrete to 6″ CI, plastic or steel9.90–10.65″6.50–6.75″
1006-88EB8″ concrete to 8″ CI, plastic or steel9.90–10.65″8.30–8.85″
1006-10-8EB10″ concrete to 8″ CI, plastic or steel12.00–12.70″8.30–8.85″
1006-1210EB12″ concrete to 10″ CI, plastic or steel14.50–15.45″10.10–10.75″
1006-1212EB12″ concrete to 12″ CI, plastic or steel14.50–15.45″11.70–12.65″
1006-1212LCEB12″ concrete to 12″ CI, plastic or steel (LC)15.10–16.00″12.25–12.65″
1006-1512EB15″ concrete to 12″ CI, plastic or steel18.90–20.20″12.25–12.65″
1051 series Ductile iron to cast iron, plastic or steel9 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1051-44EB4″ ductile iron to 4″ CI, plastic or steel4.50–4.90″4.00–4.50″
1051-46EB4″ ductile iron to 6″ CI, plastic or steel4.75–5.05″6.30–6.80″
1051-54EB5″ ductile iron to 4″ CI, plastic or steel5.50–6.15″3.95–4.55″
1051-64EB6″ ductile iron to 4″ CI, plastic or steel6.30–6.80″4.15–4.60″
1051-65EB6″ ductile iron to 5″ CI, plastic or steel6.30–6.80″5.20–5.70″
1051-84EB8″ ductile iron to 4″ CI, plastic or steel8.80–9.25″4.15–4.60″
1051-86EB8″ ductile iron to 6″ CI, plastic or steel8.55–9.25″6.50–6.75″
1051-1210EB12″ ductile iron to 10″ CI, plastic or steel12.55–13.30″10.15–10.85″
1051-1510EB15″ ductile iron to 10″ CI, plastic or steel14.90–16.00″10.30–10.75″
1055 series Ductile iron to ductile iron7 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1055-64EB6″ ductile iron to 4″ ductile iron6.35–7.10″4.80–5.10″
1055-65EB6″ ductile iron to 5″ ductile iron6.35–7.10″5.60–6.10″
1055-84EB8″ ductile iron to 4″ ductile iron8.55–9.25″4.75–5.15″
1055-86EB8″ ductile iron to 6″ ductile iron8.55–9.25″6.50–6.85″
1055-10-8EB10″ ductile iron to 8″ ductile iron10.25–10.95″8.60–9.15″
1055-1210EB12″ ductile iron to 10″ ductile iron12.55–13.30″10.65–11.35″
1055-1512EB15″ ductile iron to 12″ ductile iron15.35–16.60″13.00–13.40″
1056 series Cast iron, plastic or steel to cast iron, plastic or steel13 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1056-32EB3″ CI, plastic or steel to 2″ CI, plastic or steel3.15–3.70″2.25–2.50″
1056-315EB3″ CI, plastic or steel to 1½″ CI, plastic or steel3.15–3.70″1.80–1.95″
1056-42EB4″ CI, plastic or steel to 2″ CI, plastic or steel4.10–4.60″2.30–2.50″
1056-43EB4″ CI, plastic or steel to 3″ CI, plastic or steel4.25–4.65″3.30–3.50″
1056-54EB5″ CI, plastic or steel to 4″ CI, plastic or steel5.10–5.70″4.05–4.60″
1056-64EB6″ CI, plastic or steel to 4″ CI, plastic or steel6.30–6.80″4.15–4.60″
1056-65EB6″ CI, plastic or steel to 5″ CI, plastic or steel6.30–6.80″5.10–5.70″
1056-84EB8″ CI, plastic or steel to 4″ CI, plastic or steel8.00–8.75″4.25–4.65″
1056-86EB8″ CI, plastic or steel to 6″ CI, plastic or steel8.00–8.75″6.50–6.75″
1056-10-8EB10″ CI, plastic or steel to 8″ CI, plastic or steel10.10–10.80″8.30–8.85″
1056-1210EB12″ CI, plastic or steel to 10″ CI, plastic or steel12.00–12.75″10.25–10.75″
1056-1510EB15″ CI, plastic or steel to 10″ CI, plastic or steel14.50–15.75″10.10–10.75″
1056-1512EB15″ CI, plastic or steel to 12″ CI, plastic or steel14.50–15.75″11.70–12.65″
1057 series Concrete to ductile iron5 parts
PartConnectsFirst pipe O.D.Second pipe O.D.
1057-64EB6″ concrete to 4″ ductile iron7.30–7.90″4.50–5.15″
1057-68EBRC6″ concrete to 8″ ductile iron8.55–9.25″7.20–7.85″
1057-12-6EB12″ concrete to 6″ ductile iron14.50–15.45″6.25–6.90″
1057-12-8EB12″ concrete to 8″ ductile iron14.50–15.75″8.85–9.20″
1057-15-8EB15″ concrete to 8″ ductile iron18.75–20.25″8.85–9.20″

O.D.s are listed in the same order as the pipes in the Connects column. CI = cast iron. Connecting pipes without a critical grade? See Standard Couplings.

Specifications.

Sizes1½″ to 15″, 75 parts
ConstructionCoupling and insert bushing on most sizes. 1002-64EC is one piece.
Clamps300 series stainless steel
Maximum test pressure4.3 psi (29.6 kPa)
Maximum operating temperature140°F, non-continuous
StandardsASTM C1173 and D5926
ComplianceAIS and BABA compliant