ASTM A126 Class 125 Gray Iron Castings Companion Flat-Face Flange
Class 125 ASTM A126 Gray Iron Companion Flat-Face Flange
The Class 125 ASTM A126 Gray Iron Castings Companion Flat-Face Flange provides a durable and practical connection for commercial and industrial piping systems. Designed to provide a compatible flanged connection between pipe and Class 125 equipment, a gray iron companion flange is commonly used with valves, pumps, strainers, fittings, and other flanged components in water and mechanical piping applications.
ASTM A126 Gray Iron Castings
ASTM A126 covers gray iron castings intended for use in valves, flanges, and pipe fittings. Gray cast iron provides good compressive strength, dimensional stability, machinability, and vibration-dampening characteristics for appropriate piping systems.
Class 125 ASTM A126 gray iron components are commonly used in water distribution, HVAC systems, mechanical piping, utilities, pump installations, manufacturing facilities, fire protection systems, and general industrial piping applications.
Class 125 Companion Flange Design
A companion flange provides a mating flanged connection for compatible piping components and equipment. Depending on the specific product configuration, the companion flange may incorporate a threaded connection or another connection method for attachment to the piping system.
Once installed, the companion flange provides the bolt-hole pattern and gasket seating surface required to connect pipe to a compatible Class 125 valve, pump, fitting, or equipment flange.
The Class 125 designation represents a pressure class rather than a maximum working pressure of exactly 125 PSI. Allowable pressure depends on material grade, component design, size, temperature, and the applicable standard.
Flat-Face Flange Construction
The flat-face (FF) design provides a gasket seating surface extending across the flange face. This configuration helps distribute gasket and bolting loads across a broader area and is commonly used with gray cast iron piping components.
Proper gasket selection and controlled bolt tightening are particularly important because gray cast iron is more brittle than forged steel.
Selecting an ASTM A126 Companion Flange
When ordering a Class 125 ASTM A126 gray iron companion flat-face flange, verify nominal pipe size, ASTM A126 grade, connection type, Class 125 rating, flat-face configuration, dimensional standard, bolt pattern, gasket, bolting requirements, and mating equipment compatibility.