When selecting the appropriate thread type for a pipe nipple, the key factors to consider are:
Sealing Requirements:
NPT (National Pipe Tapered) threads are designed to create a tight, leak-free seal. They are the most common and versatile choice for plumbing and piping applications that require a strong, sealed connection.
NPSM (National Pipe Straight Mechanical) threads are not intended for sealing, but rather for mechanical strength and easy assembly/disassembly. They are less suitable for applications requiring a leak-proof seal.
Compatibility:
Match the thread type to what the nipple will be connecting to, pipe nipple threaded one end such as threaded ports, valves, fittings, etc. Using the correct thread type ensures a proper fit.
NPT threads are the most common and widely used, so they provide the best overall compatibility.
Working Pressure/Temperature:
NPT threads generally have a higher pressure and temperature rating compared to NPSM.
For high-pressure or high-heat applications, NPT is the preferred choice.
Disassembly Requirements:
NPSM threads are easier to assemble and disassemble than NPT, which have a tighter, more permanent seal.
If frequent disassembly is needed, NPSM may be the better option.
In summary, NPT threads are the default choice for most plumbing, piping, and fluid handling applications that require a reliable, leak-proof seal. NPSM is better suited for mechanical applications where a strong but easily disassembled connection is the priority. Carefully considering the application needs will help determine the appropriate thread type for your pipe nipple.
