How do I spot a Z-COAT fitting?

The fitting is stenciled "ZINC" on the outside, and its item number ends in Z.

My spec calls for ISO 8179-1. Can I use Z-COAT?

The two standards call for the same amount of zinc and differ in how it goes on. Whether ISO 8179-2 can be used in its place is up to the engineer of record. Your regional team can send the Z-COAT information sheet and SIGMA's zinc fact sheet for the submittal.

Can Z-COAT be repaired in the field?

Yes. Zinc-rich paint, such as SIGMA Z-COAT, is specified for field repairs, per the Z-COAT information sheet.

Do I still need polyethylene encasement?

In highly corrosive soils, the Z-COAT information sheet suggests Z-COAT fittings with an enhanced polyethylene encasement. For any job, follow the engineer's spec.

Where are Z-COAT prices?

Z-COAT fittings have their own item numbers and list prices on SIGMA's zinc price lists: Import Fittings-Zinc (PDF) and Domestic Fittings-Zinc (PDF). Ceramic epoxy lined Z-COAT fittings are on their own import list. On a fitting page, pick a zinc coating.

Home › Coatings and Linings › SIGMA Z-COAT

SIGMA Z-COAT.

For engineers, distributors and contractors protecting ductile iron fittings in corrosive soil: zinc-rich paint under a black asphalt top coat, applied per ISO 8179-2.

Fittings With Z-COAT

Z-COAT or Arc Zinc?

✓ ISO 8179-2 ✓ Fitting item numbers end in Z

Line drawing of a mechanical joint 90 degree bend

MJ fittings

C153 compact and C110 full body mechanical joint fittings.

Import and domestic · C153 3 to 48 in. · C110 2 to 48 in.

View C153 MJ ›
View C110 MJ ›

Push-on fittings

C153 push-on fittings.

Import and domestic · 4 to 24 in.

View push-on fittings ›

Line drawing of a flanged 90 degree bend

Flanged fittings

C110 flanged fittings.

Import 2 to 48 in. · domestic 2 to 54 in.

View flanged fittings ›

How zinc protects iron.

Zinc is less noble than iron, so it corrodes first and protects the fitting. Applied as a liquid, Z-COAT fills the peaks and valleys of a cast surface, and it can heal over a small flaw.

Black MJ bends on a pallet with zinc showing at the bell faces

85 %

Zinc in the dry film, at least, under the black asphalt top coat.

3.5 mil

Physical barrier, on top of the zinc's galvanic protection.

From the SIGMA Z-COAT product information sheet, October 2026.

ISO 8179-2: SIGMA Z-COAT

Zinc-rich paint, sprayed on as a liquid. 200 g of zinc per square meter, about 3.5 to 4 mils thick. Recommended for field repairs to either coating. SIGMA's choice for fittings: the paint covers a rough cast surface and builds a thicker barrier.

View Fittings With Z-COAT

ISO 8179-1: arc zinc

Zinc melted and sprayed on, then it solidifies on the iron. 200 g of zinc per square meter, about 1 to 1.25 mils thick. Not recommended for field repairs. In SIGMA's experience, the process suits pipe but does not lend itself to fittings. If your spec calls for it, ask your regional team.

Find Your Regional Team

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Questions about Z-COAT.

Short answers. Your regional team has the rest.

SIGMA's zinc coating for ductile iron fittings: a zinc-rich paint applied per ISO 8179-2, not less than 85% zinc in the dry film, under a black asphalt top coat. Inside, Z-COAT fittings are cement lined and asphalt coated per AWWA C104, except the ceramic epoxy lined Z-COAT fittings, which have their own import price list.

Specifying zinc?

Your regional team can price Z-COAT fittings and send the Z-COAT information sheet for your submittal.

Headquarters, Cream Ridge, NJ

800.999.2550

Find Your Regional Team

Fittings With Z-COAT

SIGMA Z-COAT.