Bk 521-205BG Malleable Black Iron Coupling 1 in

Product Description

The BK 521-205BG is a 1-inch malleable black iron coupling designed for threaded pipe connections in gas, water, and general-purpose piping systems. Manufactured from malleable iron conforming to ANSI/ASTM A-197, this coupling accepts standard NPT threads per ANSI B1.20.1 and meets dimensional standards ANSI/ASME B16.3, B16.14, and B16.39. Each fitting is individually flag tagged and 100% inspected and quality tested before leaving the factory. At 0.474 pounds, it is a solid, durable component suited for residential and light commercial installations. Licensed plumbers and pipefitters install this coupling in new construction and retrofit applications where a straight inline pipe connection is required.

This coupling is used in residential and commercial plumbing, gas distribution, and mechanical piping systems where 1-inch black iron pipe is specified. Black iron fittings of this type are common in natural gas and propane supply lines, fire suppression rough-in, and industrial air lines. The fitting is sold individually and is appropriate for any application that calls for a standard malleable iron threaded coupling at the 1-inch pipe size.

Key Features

• Malleable iron construction per ANSI/ASTM A-197 for strength and ductility
• Threaded to ANSI B1.20.1 NPT standard for reliable, leak-resistant connections
• Dimensions conform to ANSI/ASME B16.3, B16.14, and B16.39
• 100% inspected and quality tested at the factory
• Individually flag tagged for easy identification and inventory control
• 1-inch pipe size suits a wide range of residential and commercial piping applications

Compatibility

Designed as a standard OEM-style replacement or new-installation fitting compatible with 1-inch NPT black iron pipe systems.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with the International Plumbing Code or International Fuel Gas Code as applicable. Shut off gas or water supply and relieve system pressure before disassembling any threaded connections. Apply an approved thread sealant or PTFE tape to male threads before assembly. Do not over-torque fittings, as malleable iron can crack if excessive force is applied.

Technical Specifications

• Material: Malleable Black Iron, ANSI/ASTM A-197
• Pipe Size: 1 inch
• Thread Standard: ANSI B1.20.1 NPT
• Dimensional Standards: ANSI/ASME B16.3, B16.14, B16.39
• Weight: 0.474 pounds
• Unit of Measure: Each

Standard Information

• Brand: BK
• Manufacturer Part Number: 521-205BG