A pipe nipple is a short tubular fitting used in pipeline systems to connect different pipe sections, typically featuring external threads on both ends and made of metal or plastic in straight or tapered configurations.
Classification
Thread Types: NPT/BSPT
Structural Types: Concentric/Eccentric
Materials: Carbon steel/Stainless steel/Brass
Length: Short nipple/Long nipple
Pipe nipples are primarily applied in sealing connections for petroleum, chemical, water supply, and other industrial fields. These fittings are manufactured in compliance with the ASME B16.11 standard. For production, sales, or any inquiries, please contact us.
Pipe nipple core parameters and charts
NPS range: DN8 (1/4″) to DN600 (24″), with DN15 (1/2″) to DN300 (12″) being the most commonly used.
Wall thickness grades: ch5 (thin wall) to Sch160 (extra thick wall).
Wall thickness tolerance: Sch40 allows +12.5%/-10% deviation, Sch80 allows +10%/-8%
Standard length: 60mm to 300mm (short section type), long type up to 1200mm.
Thread length: NPT threads according to ASME B1.20.1, 1/2″ pipe thread length ≥ 15mm.
OD tolerance: ANSI B36.10: OD tolerance is ±1% or ±0.5mm (whichever is greater).
Pipe Nipple Specifications
Thread type of pipe nipple
Npt pipe nipple: American Standard pipe nipple, tooth angle 60°, taper 1:16, in accordance with ASME B1.20.1 and GB/T 12716-1991, mainly used in high pressure sealing connection. It is mainly used for high-pressure sealing connection. It needs to be matched with the same standard internal thread.
BSPT pipe nipple: tooth angle 55°, taper 1:16, corresponds to ISO 7-1 standard, for European market, gas system. Required for Rc/R series threads.
G series straight thread: tooth angle 55°, no taper, according to GB/T 7307-2001, for low pressure non-sealing scenario.
Users can quickly distinguish the thread type according to the different labeling, for example: American Standard sealing thread labeled “NPT 1/2”, non-sealing thread “G 1/4”.
How to choose the thread of pipe nipple? First of all, you need to determine whether the pipe is sealed or not, if the pipe is working under high temperature and high pressure system, you should prefer conical sealing threads such as NPT or BSPT. For low pressure system, you should choose G series straight threads.
Structural forms of pipe nipple
The structural forms of pipe nipple are concentric and eccentric.
Concentric structure: the centerlines of the two pipe diameters overlap at both ends, and the transition section is symmetrically tapered.
Eccentric structure: both ends of the pipe diameter centerline offset (flat top or flat bottom design), forming an asymmetric transition section.
Material of pipe nipple
Pipe nipple The main materials are carbon steel, stainless steel, alloy steel, duplex steel, nickel-chromium alloy. Some piping systems will also need brass, cast iron and so on. Among them, carbon steel and stainless steel are more basic materials, the application will be more widely used.
Ordinary carbon steel: suitable for room temperature and low pressure system, can provide good mechanical strength, reduce the cost, the standard has ASTM A105.
Forged carbon steel: suitable for socket weld and threaded connection scenarios, commonly used in chemical piping, such as ASTM A733 standard.
Stainless steel: corrosion resistance please, used in food, marine, pharmaceutical and other industries.
PVC pipe nipple: acid and alkali resistant, low cost, but poor temperature resistance (≤80℃), suitable for drainage and low pressure pipes.
PU pipe nipple: high elasticity, superior abrasion resistance, suitable for dynamic need to bend the scene.
Suggestions for selection:
Corrosive environment: prioritize stainless steel or PVC;
High pressure and high temperature: choose carbon steel/alloy steel;
Flexibility needs: consider PU material.
Pipe Nipple Length Classification Analysis
In addition to the above data of pipe fittings, you should also pay attention to the length when buying pipe nipples.Pipe nipples are classified into long and short sections according to their length. Pipe nipples with a length between 60mm-300mm are short nipples and those with a length between 300mm-1200mm are long nipples.
FireMinus Pipe Nipple Products
Pipe nipples are made using three processes: threading, welding and surface treatment.
Threading process: CNC machine tools are used to control the dimensions according to NPT/BSPT standards to ensure that the dimensions of the product are accurate and within tolerance.
Welding process: Both ends are processed with welding bevel (V/U type), the bevel angle is usually 30°~45°, and the thickness of obtuse edge is 1~2mm.
Surface treatment: Carbon steel needs to be galvanized or coated with epoxy resin anticorrosive layer, and stainless steel needs to be pickled and passivated. Ensure that the pipe fittings longer life.
Pipe Nipple Process and Installation Specifications
Pipe Nipple Process
Pipe nipples are made using three processes: threading, welding and surface treatment.
Threading process: CNC machine tools are used to control the dimensions according to NPT/BSPT standards to ensure that the dimensions of the product are accurate and within tolerance.
Welding process: Both ends are processed with welding bevel (V/U type), the bevel angle is usually 30°~45°, and the thickness of obtuse edge is 1~2mm.
Surface treatment: Carbon steel needs to be galvanized or coated with epoxy resin anticorrosive layer, and stainless steel needs to be pickled and passivated. Ensure that the pipe fittings longer life.
Pipe Nipple installation specification
The first step: check the work before installation, pipe nipple’s data is qualified, whether it has anti-corrosion coating, pipe fittings surface is clean and smooth.
Step 2: Installation. If it is NPT threaded pipe fittings, you need to wrap the raw material tape or apply sealant, pay attention to the winding direction needs to be opposite to the direction of the thread. After screwing, the leakage thread is not more than 1.5 teeth to be qualified.
The third part: check. Sealing test, need to water pressure is 1.5 times the design pressure, and keep 10 minutes without leakage. Threaded joints are qualified if there is no tilt visible to the naked eye.
What is the difference between pipe coupling and nipple?
Core structure
pipe coupling: complete connection assembly with male and female couplings; pipe nipple: a single short pipe with threaded or welded ends
Connection:
pipe coupling: quick connection by means of snap fit or bolt compression without welding or flange butt joints; pipe nipple: directly screwed or welded to the pipe/pipe/pipe nipple; pipe nipple: directly screwed or welded to the pipe/pipe nipple; pipe nipple: as a transition section to fill installation gaps or extend pipe spacings. Equipment fixing
Functions:
pipe coupling: as a butt element between pipes, providing both sealing and restriction; pipe nipple: as a transition section to fill installation gaps or extend pipe spacing.
