3 in. 150# Cast Iron Companion Flange | 77843
The 3 in. cast iron companion flange (part 77843) adapts threaded pipe to flanged connections — thread it onto pipe and bolt it to a flanged valve, pump, strainer, or piece of equipment. 150 lb pressure class, cast iron construction. Companion flanges are the standard way to install wafer-style butterfly and check valves on threaded pipe systems.
Technical Specifications
| Manufacturer Part Number (MPN) | 77843 |
| Nominal Size | 3 in. |
| Fitting Type | Companion flange, threaded |
| Pressure Class | 150 lb |
| Material | Cast Iron |
Need bolt-circle, bolt-hole, or thickness dimensions for your installation? Contact us and we will confirm dimensional details against the manufacturer drawing before you order.
Other Sizes in This Series
150# Cast Iron Companion Flange, threaded (1-1/4"–8"; no 2" made in this class). Jump to another size or add it straight to your cart:
| Size | Part # | Price | Cart |
| 1-1/4 in. | 77932 | $67.99 | Add to cart |
| 1-1/2 in. | 77840 | $98.99 | Add to cart |
| 2-1/2 in. | 77842 | $160.99 | Add to cart |
| 3 in. (this page) | 77843 | $151.99 | — |
| 4 in. | 77845 | $251.99 | Add to cart |
| 6 in. | 77846 | $814.99 | Add to cart |
| 8 in. | 77933 | $2,219.99 | Add to cart |
Typical Applications
Mounting wafer butterfly valves and double-door wafer check valves on threaded pipe runs, connecting threaded steel or iron pipe to flanged pumps and strainers, and transitioning between threaded and flanged piping in HVAC, water distribution, and general industrial systems. Pair two flanges to sandwich a wafer-style valve.
Cross-References & Interchange
Replacing an existing 3 in. 150 lb threaded companion flange? Match nominal size, pressure class, and material for a direct fit — or send us your part number and we will confirm the interchange.
Availability
In stock — ships direct from the manufacturer, typically 1–3 business days.