NPT Threads Enhance the Quality of Filtration in Wedge Wire Products

In the realm of efficient filtration and screening, wedge wire screen products play an indispensable role, providing reliable solutions for various industries. Among these, NPT threads, as part of connection technology, are particularly important. NPT, or National Pipe Thread, is a widely used thread standard in the field of piping connections, with a unique design that excels in various applications.

This article will guide you through the basics of NPT threads and their key role in the wedge wire products we produce. Through technical specification data tables and illustrative explanations, we will unveil the exceptional performance of NPT threads in wedge wire products and our company's efforts in production processes and quality control. Join us as we explore how this connection technology can provide outstanding support for your filtration needs.

What is NPT Thread?

NPT, or National Pipe Thread, is an American standard for tapered threads commonly used to connect pipes and fittings. Known for its effective sealing performance, NPT threads are ideal for low-pressure liquid and gas pipelines. Characterized by a 60-degree thread angle, large pitch, and a slightly smaller diameter at the top and bottom compared to the middle, NPT threads adhere to the American National Standards Institute (ANSI) standard, specifically ANSI/ASME B1.20.1. This standard, which outlines dimensions, pitch, thread angle, and shape, ensures interchangeability across NPT threads produced by different manufacturers.

A drawing of NPT thread connection structure
NPT thread Quality inspection

Quality inspection of NPT (National Pipe Thread) threads is important to ensure proper functionality and leak-free connections. Common methods used for NPT quality Inspection usually include Thread Gauge, Visual Inspection, Thread Pitch Gauge, Thread Engagement Verification, Thread Sealant Verification, Pressure Testing, etc. Thread Gauge and Visual Inspection are commonly used.

NPT Thread Specification Sheet
Thread Size
Outside Diameter
Threads per
Pitch of Threads
Length of effective thread
1/8" 0.405" 27" 0.03704" 0.261"
1/4" 0.540" 18" 0.05556" 0.401"
3/8" 0.675" 18" 0.05556" 0.408"
1/2" 0.840" 14" 0.07143" 0.534"
3/4" 1.050" 14" 0.07143" 0.546"
1" 1.315" 11.5" 0.08696" 0.682"
1-1/4" 1.660" 11.5" 0.08696" 0.707"
1-1/2" 1.900" 11.5" 0.08696" 0.724"
2" 2.375" 11.5" 0.08696" 0.756"
2-1/2" 2.875" 8" 0.12500" 1.136"
3" 3.500" 8" 0.12500" 1.200"
3-1/2" 4.000" 8" 0.12500" 1.250"
4" 4.500" 8" 0.12500" 1.300"
5" 5.563" 8" 0.12500" 1.406"
6" 6.625" 8" 0.12500" 1.513"
8" 8.625" 8" 0.12500" 1.713"
10" 10.750" 8" 0.12500" 1.925"
12" 12.750" 8" 0.12500" 2.125"
14" 14" 8" 0.12500" 2.250"
16" 16" 8" 0.12500" 2.450"
NPT thread in wedge wire screen

NPT thread nipple is often used in our wedge wire filter nozzles and wedge wire filter elements. When working with NPT threads, it is important to follow industry standards and guidelines for proper installation, torque values, and thread engagement to ensure a reliable and leak-free connection.

Checking the joint thread of a wedge-shaped nozzle with a thread gauge.

Inspecting the thread of a joint using a thread gauge

Comparative illustration of two ways to open the threaded end of a long-handle type wedge-shaped nozzle.

Detail of the NPT threaded joint on a wedge wire filter nozzle

A wedge wire screen tube with an NPT threaded end

Detail of the NPT threaded joint on a wedge wire screen tube