Victaulic Style 743 / 744
Victaulic flange adapters for the transition from grooved pipe to flanged equipment or valves.
Style 743 and Style 744 are Victaulic flange adapters, used to connect a grooved pipe to flanged equipment, a valve or a pump, without welding at the grooved end. Style 743 covers 2–12 in (DN50–DN300), withstands up to 720 psi (50 bar) and fits ANSI Class 250 and 300 flanges, for general use at high pressures. Style 744 is the FireLock version, UL/FM certified for sprinkler systems, in the 2–8 in (DN50–DN200) range, at a maximum of 175 psi, compatible with ANSI Class 125 and 150 bolt patterns.
For a quotation we need the nominal size, the required series (743 or 744), the class of the flange to be mated and, where relevant, any fire protection certification requirement. We supply the adapters made to order from the European Union, in 1–4 weeks; we do not confirm compatibility with other fittings other than by checking directly in the Victaulic documentation.
Models and codes
| Code | Note |
|---|---|
| Style 743 – 2"/DN50 | Flange adapter, ANSI Class 250/300, 720 psi |
| Style 743 – 4"/DN100 | Flange adapter, ANSI Class 250/300, 720 psi |
| Style 743 – 8"/DN200 | Flange adapter, ANSI Class 250/300, 720 psi |
| Style 743 – 12"/DN300 | Largest size in the Style 743 range |
| Style 744 – 2"/DN50 | FireLock, UL/FM, ANSI Class 125/150, 175 psi |
| Style 744 – 6"/DN150 | FireLock, maximum end load 6000 lbf |
| Style 744 – 8"/DN200 | Largest size in the Style 744 range |
Key specifications
| Size range, Style 743 | 2–12 / DN50–DN300 in |
|---|---|
| Maximum working pressure, Style 743 | 720 / 50 psi / bar |
| Flange standard, Style 743 | ANSI Class 250 and 300 |
| Size range, Style 744 | 2–8 / DN50–DN200 in |
| Maximum working pressure, Style 744 | 175 / 12.07 psi / bar |
| Flange standard, Style 744 | ANSI Class 125 and 150 |
| Body material | Ductile iron ASTM A536 65-45-12 |
| Certification, Style 744 | UL Listed / FM Approved |
Victaulic technical literature for Style 743 (doc. 06.06) and Style 744 (doc. 10.04) is current in the manufacturer's documentation, with no mention of withdrawal from production.
Frequently asked questions
What do you need for a quotation on a Style 743 or 744 adapter?
The nominal size (in or DN), the required series, the class of the flange to be mated (ANSI 125/150 or 250/300) and, if the adapter is for a fire protection installation, the UL/FM listing requirement. We then check the correct size and pressure in the Victaulic documentation.
What is the practical difference between Style 743 and Style 744?
Style 743 is the general-purpose adapter, with a much higher maximum pressure, for industrial equipment and valves. Style 744 is the FireLock version, UL listed and FM approved, designed specifically for wet or dry sprinkler networks at lower pressures.
What do we check before quoting a Victaulic series?
We do not confirm the compatibility of an adapter with fittings from other manufacturers or with Victaulic FireLock/"V" variants. Style 744 is not used on such fittings; we check compatibility for each project.
We do not design the pipe grooving system; we only check the size and pressure class in the Victaulic documentation before quoting.
Updated: 2026-11-12