3/4 inch x Close Black Steel Nipple

3/4" x Close Black Steel Nipple – Threaded Pipe Extension for High-Pressure Systems

The 3/4" x Close Black Steel Nipple is a Schedule 40 fitting designed for tight inline connections in threaded steel piping systems. It is commonly used in compressed air, gas, and hydronic systems where space constraints require minimal exposed pipe length between fittings or valves. The “close” length designation indicates threads nearly meet end-to-end, leaving no visible unthreaded pipe body.

Constructed from welded black carbon steel pipe, the nipple is precision-machined to ANSI/ASME B1.20.1 standards. It is manufactured for compatibility with other NPT-threaded components and is suitable for non-potable, low- to medium-pressure systems operating under thermal or mechanical stress.

Product Specifications

• ✅ Nominal Size: 3/4 inch
• ✅ Length: Close (fully threaded; minimal shoulder)
• ✅ Material: Black steel, Schedule 40
• ✅ Thread Type: Male NPT (tapered pipe threads per ANSI B1.20.1)
• ✅ Standard Compliance: ASME B16.3, ASTM A53/A733

Functional Characteristics

• ✅ Compact Installation – Close design ideal for tight coupling between two female-threaded components with no exposed pipe
• ✅ Thread Integrity – Tapered threads provide reliable mechanical seal when used with PTFE tape or thread compound
• ✅ System Compatibility – Suitable for gas, oil, steam, and closed-loop hydronic systems
• ✅ Black Coating – Provides basic corrosion resistance in dry environments; not for potable water

Installation Considerations

Install using appropriate pipe wrenches or spanner tools. Apply thread sealant or PTFE tape to male threads before tightening. Care must be taken not to over-torque, which may compromise thread sealing surfaces or cause stress cracking in mating components. System pressure testing is recommended after assembly.

Typical Use Cases

This close nipple is used in industrial manifolds, boiler connections, gas risers, and control assemblies where a minimal connection gap is required. Common applications include mechanical rooms, compressor stations, and gas distribution networks.

Advisory

Black steel fittings are intended for use in non-potable systems only. For potable water service, use galvanized or approved brass alternatives per local code. Always consult project specifications or code officials for material suitability.

The 3/4" x Close Black Steel Nipple offers dimensional precision and mechanical durability for field installations requiring compact, high-strength threaded connections.