316 Casting Fitting Union 2" Class 150 Threaded NPT

What is Cast Union?
The cast union is a special pipe fitting consisting of three parts, designed specifically for pipeline points that require frequent disassembly or maintenance. It includes two threaded ports and a central nut for locking. Tightening the nut can tighten the two ends, forming a reliable seal. The ingenious structure of the union allows it to provide a secure connection while allowing easy disconnection without rotating the pipeline, greatly facilitating equipment replacement and pipeline maintenance work.

Introduction to Thread Types
Threaded fittings primarily adhere to two major international thread systems: NPT and BSP. The thread angle of NPT (American Standard Pipe Taper Thread) is 60°, relying on the thread's own taper (1:16) for sealing. The thread angle of BSP (British Standard Pipe Thread) is 55°, which is divided into taper threads (BSPT) for sealing and parallel threads (BSPP). This union adopts NPT threads, which are the most common connection form in North America and the general industrial field.

CF8M/316 Material Properties
The selection of CF8M/316 stainless steel material is crucial for ensuring the long-term reliable operation of the union. Due to the presence of molybdenum, the 316 grade exhibits superior corrosion resistance, particularly against chloride corrosion, compared to the 304 grade. For the union, this means that its precise threads and sealing surfaces are less prone to getting stuck or damaged due to rust, ensuring both the sealing performance during daily operation and the ease of disassembly for maintenance after many years.

SMLSCO Production Process
Our cast pipe fittings are produced using precision casting (sol silica) technology to achieve excellent dimensional accuracy and surface finish. The process begins with the creation of a wax mold, which is then coated with multiple layers of refractory material to form a ceramic shell. The shell is then heated, causing the wax to melt and flow out. Next, molten stainless steel is poured into the hollow shell. After the steel cools and solidifies, the shell is broken off to obtain a high-precision pipe fitting blank. The blank is then machined, tapped, and other processes to produce the final product.

Application of Casting Fitting Union
Class 150-pound cast union fittings are core components that enhance maintenance convenience for low-pressure piping systems. They are typically installed at both ends of equipment such as pumps, valves, filters, and storage tanks, or at locations in the pipeline where maintenance disconnection points need to be reserved. In commercial water supply and drainage, HVAC, and general industrial fluid piping, the use of union fittings can greatly simplify the installation, maintenance, and replacement processes of equipment, saving long-term maintenance costs.