Bk 521-208BG Malleable Black Iron Coupling 2 in

Product Description

The BK 521-208BG is a 2-inch malleable black iron coupling designed for threaded pipe connections in plumbing, gas, and mechanical piping systems. Malleable iron construction provides the ductility and strength required for standard pressure service in commercial and residential installations. Each fitting carries the Mueller logo cast directly into the body and is individually flag tagged for easy identification in the field. All fittings in this line are 100% inspected and quality tested before shipment. Threads conform to ANSI B1.20.1 for consistent, leak-resistant makeup with standard NPT pipe.

This coupling is used wherever a same-size threaded pipe joint is required in black iron piping systems, including natural gas distribution, steam lines, compressed air, and general plumbing rough-in. The 2-inch size fits common main-line and branch applications in both residential and light commercial settings. Licensed plumbers, pipefitters, and mechanical contractors are the typical installers. The fitting ships as a single unit.

Key Features

• Malleable iron construction meets ANSI/ASTM A-197 material specification
• Dimensional compliance with ANSI/ASME B16.3, B16.14, and B16.39
• NPT threads cut to ANSI B1.20.1 for reliable, standard-compliant makeup
• Mueller logo cast into body for brand and quality traceability
• Individually flag tagged for fast field identification
• 100% inspected and quality tested

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 2-inch NPT threaded black iron piping systems in gas, steam, compressed air, and general plumbing applications.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local codes and the International Fuel Gas Code or International Plumbing Code where required. Shut off all gas or fluid supply and relieve system pressure before disassembling any threaded joint. Apply an appropriate thread sealant or PTFE tape rated for the service medium before making up the joint. Do not over-tighten malleable iron fittings, as excessive torque can crack the fitting body.

Technical Specifications

• Material: Malleable Black Iron
• Pipe Size: 2 inches
• Thread Standard: ANSI B1.20.1 NPT
• Material Specification: ANSI/ASTM A-197
• Dimensional Standards: ANSI/ASME B16.3, B16.14, B16.39
• Weight: 1.438 pounds
• Unit of Measure: Each

Standard Information

• Brand: BK
• Manufacturer Part Number: 521-208BG