ZIP FLANGE with its set screws, catalog render

The item number sets the size and the pipe.

Item # ZF2-C6 Questions and answers (7)

ZIP FLANGE Set-Screw Adapter

Ductile iron flange that set-screws onto plain-end pipe in the field: ZF2-C for ductile iron pipe, ZF2-S for steel pipe, 2 to 12 in. Not for plain-end fittings.

View price list (PDF)

Rated 200 psi at 6 in.
Drilled to ANSI B16.1, 125 lb
SBR gasket standard; EPDM, neoprene and nitrile on request
See all specifications

Model: ZF2-C, ductile iron pipe

Size: 6 in.

Made: Import

Listed on the Import Restraint Products price list. Domestic-content requirement on the job? Ask your regional team.

Coating: Standard

Red alkyd paint.

Your distributor

SIGMA sells through waterworks distributors. Order with item # ZF2-C6.

Quote from SIGMA

Job location

Sends your quote list to the right regional team.

Quantity

Download the ZIP FLANGE catalog

Need help on the job?

Call 800.999.2550 with the pipe, its class or schedule, and the size.

ZIP FLANGE or SFUP? All flange adapters Catalog with the torque table (PDF)

Everything about the 6 in. ZIP FLANGE ZF2-C, ductile iron pipe.

Details, specs, every size and the questions buyers ask. Open what you need.

Product detailsWhat it is, highlights and documents

About the ZIP FLANGE

The ZIP FLANGE, model ZF2, is a field-installed flange adapter: a ductile iron flange whose set screws tighten against plain-end ductile iron or steel pipe, so the pipe can be bolted to a flanged fitting, pump or valve.

ZF2-C fits ductile iron pipe (cast iron OD); ZF2-S fits steel pipe. Both come 2 to 12 in. For 14 in. and up, the catalog points to the SFUP; for steel pipe 14 in. and up, ask your regional team.

It is not designed for plain-end fittings.

Highlights

2 to 12 in.: ZF2-C for ductile iron pipe, ZF2-S for steel pipe
Flange in ductile iron, ASTM A536 Grade 65-45-12
200 psi at 2 to 8 in.; 175 psi at 10 and 12 in.

Documents

Specifications6 in. ZIP FLANGE ZF2-C, ductile iron pipe · 200 psi

6 in. ZIP FLANGE ZF2-C, ductile iron pipe

Item number	ZF2-C6
Model	ZF2-C, ductile iron pipe
Size	6 in.
Made	Import
Coating	Standard
Pressure rating	200 psi
Max. deflection
Weight	10 lb
Crate quantity
Catalog page	Page 2 of the ZIP FLANGE catalog
Price list	Import Restraint Products, effective 12/9/24, rev. 4/14/26

Materials

Flange	Ductile iron, ASTM A536 Grade 65-45-12
Set screws	AISI 4140 steel, heat treated and zinc plated. FM approved ZIP FLANGES use break-off top set screws
Gasket	SBR, -10 to 160°F, for water, wastewater and most moderate chemicals. EPDM (-10 to 250°F), neoprene (-10 to 225°F) and nitrile (20 to 180°F) on request
Coating	Red alkyd paint

Ratings and standards

Pressure rating	200 psi at 2 to 8 in.; 175 psi at 10 and 12 in.
Drilling	ANSI B16.1, 125 lb
Standards	ANSI/AWWA C110/A21.10 and ASME B16.1, per the spec sheet
Pipe OD	ZF2-C, cast iron OD: 2.50 in. at 2 in. to 13.20 in. at 12 in. ZF2-S, steel OD: 2.375 in. at 2 in. to 12.750 in. at 12 in. Every size is in the catalog table
FM approval	The catalog recommends FM approved ZIP FLANGES, with break-off top set screws, on ductile iron pipe class 52 and up and steel pipe schedule 40 and up: ask your regional team for those items
Traceability	Each flange is cast with heat code information

Installation

Before you start	The pipe end must be square cut and burr-free. Clean it and lubricate it with a soap-based pipe gasket lubricant
Fit up	Slide the ZIP FLANGE onto the pipe, set-screw side first. Lubricate the gasket and slide it on, tapered side first. Slide the flange toward the pipe end, seating the gasket, until its face is flush with the pipe end. Hand-tighten the set screws
Flange bolts	Use standard flange bolts. Tighten them alternately to keep the faces square; when the faces meet, torque them to specification
Set screw torque	Tighten evenly to the value for the pipe below. No values are given for ductile iron class 50 at 2 to 4 in. or steel schedule 20 and 30 at 2 to 6 in.
DI class 50	50 ft-lbs at 6 to 10 in.; 60 at 12 in.
DI class 51	50 ft-lbs at 2 to 4 in.; 60 at 6 to 12 in.
DI class 52	70 ft-lbs at 2 to 6 in.; 80 at 8 to 12 in.
DI class 53 and up	70 ft-lbs at 2 to 6 in.; 90 at 8 to 12 in.
Steel schedule 20	50 ft-lbs at 8 to 12 in.
Steel schedule 30	50 ft-lbs at 8 and 10 in.; 60 at 12 in.
Steel schedule 40 and up	35 ft-lbs at 2 in.; 50 at 3 in.; 70 at 4 and 6 in.; 90 at 8 to 12 in.

From the ZIP FLANGE catalog (May 2024) and spec sheet (October 2022). Weights are from the catalog table, one per size for ZF2-C and ZF2-S. Dimensions are in the catalog, under Documents.

Every size and item number7 sizes of the ZIP FLANGE ZF2-C, ductile iron pipe · Import, Standard · item numbers

Showing the ZIP FLANGE ZF2-C, ductile iron pipe, Import, Standard. Item numbers follow the options above. Pick a size to load it.

ZIP FLANGE: item numbers, ratings and weights by size
Item #	Rating	Weight
ZF2-C2	200 psi	4 lb
ZF2-C3	200 psi	5 lb
ZF2-C4	200 psi	8 lb
ZF2-C6	200 psi	10 lb
ZF2-C8	200 psi	16 lb
ZF2-C10	175 psi	22 lb
ZF2-C12	175 psi	31 lb

Weights from the catalog table. Pipe OD by size is in the catalog.

Questions and answers7 questions buyers ask about the ZIP FLANGE

Where do I find the price?

On SIGMA's price lists. Where an item is on a posted list, the View price list button near the top of this page opens it, and every posted list is on the Price Lists page. SIGMA sells through waterworks distributors, and your distributor sets your price. For contract pricing, ask your regional team.

ZF2-C or ZF2-S?

The catalog says the ZIP FLANGE connects plain-end ductile iron or steel pipe. It lists ZF2-C under cast iron pipe OD (2.50 in. at 2 in. to 13.20 in. at 12 in.) and ZF2-S under steel pipe OD (2.375 in. to 12.750 in.). Both get the same rating, drilling and weight by size; the item number sets the pipe.

What pressure is it rated for?

200 psi at 2 to 8 in. and 175 psi at 10 and 12 in.

What torque do the set screws take?

It depends on the size and on the pipe class or schedule; the catalog table runs from 35 to 90 ft-lbs. It has no values for ductile iron class 50 at 2 to 4 in. or steel schedule 20 and 30 at 2 to 6 in.: ask your regional team before you use it there. Every value is under Specifications.

Is it UL listed or FM approved?

The catalog and spec sheet carry UL and FM marks but do not say which items. FM approved ZIP FLANGES have break-off top set screws, and the catalog recommends them on ductile iron pipe class 52 and up and steel pipe schedule 40 and up. The items on this page are the standard ZF2 series: ask your regional team which items are listed or approved.

Can I put it on a plain-end fitting?

No. It is not designed for plain-end fittings. Ask your regional team what to use on one.

Which gaskets are there?

SBR comes standard, rated -10 to 160°F for water, wastewater and most moderate chemicals. EPDM, neoprene and nitrile on request.

How a ZIP FLANGE goes on.

Three basic steps. The catalog has the drawings and the torque table.

Prep the pipe, then slide it on.

Seat it flush, snug the screws.

Bolt up, then torque the screws.

Sliding a ZIP FLANGE onto a pipe end, catalog drawing

Shown: the flange going onto the pipe.

Hand-tightening the ZIP FLANGE set screws, catalog drawing

Shown: hand-tightening the set screws.

Tightening the ZIP FLANGE set screws with a wrench, catalog drawing

Shown: tightening the set screws. Catalog with the torque table (PDF)

SIGMAFlange Universal (SFUP)

Joint pack for plain-end pipe: ductile iron 3 to 36 in., C900 PVC 4 to 36 in., steel and IPS PVC 3 to 12 in. For 3 in. on steel, ask your regional team.

See SFUP ›