Malleable Iron 340 Conical Joint Union NPT Thread

Size: 1/4”-4”
Material: ANSI/ASTM A197-A,KTH350-10
Dimension: ANSI/ASTM B16.3/14/39
Thread: ANSI/ASTM B1.20.1,NPT
Pressure Rating: 363PSI,CLASS150
Surface Treatment:Hot-dip Galvanized,Electro Galvanized,Black
Zinc Coating: ASTM A 153
Certificate: UL Listed / FM Approved / NSF 61
Application: Fire Protection,Waterworks,HVAC,Plumbing,GAS,Irrigation,or other piping systems

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Product Description

Products Details

Malleable Iron 340 Conical Joint Union. Conical Joint Union is a union which the inner seat is tapered and without gasket inside. Conical joint union can be threaded by NPT or BSPT, depends on the client’s requirement and local malleable iron pipe fittings’ standard. The size is from 1/4″ to 4″ that’s from DN6 to DN100. Both of them are FM approved and UL listed.

Product Drawing

Size L(mm) PCS/CTN.
1/2″ 47 180
3/4″ 51.5 120
1″ 57 88
1-1/4″ 65 56
1-1/2″ 71 36
2″ 79 28
2-1/2″ 85.5 12
3″ 94.5 10
4″ 110.5 6

The difference between conical joint union and flat seat union :

Tapered Unions: As mentioned earlier, tapered unions have a conical or tapered sealing surface. These fittings feature tapered male and female connections with sealing surfaces designed to fit tightly, creating a strong seal when connected. Tapered fittings are often used because of their ease of assembly, versatility, and secure fit.

Flat Seat Couplings: Flat seat couplings have flat sealing surfaces on both the male and female parts. Rather than having a tapered design, these joints rely on flat surfaces that press against each other when connected. The seal is achieved by the pressure exerted when the male and female parts are tightened together. Flat seat couplings are typically used in applications that require a tight seal but may not be suitable for tapered designs.

How to choose taper union or flat seat union:

Taper Union: The Taper Union adopts a tapered design, and its sealing surface is tapered, which can provide a stronger seal during connection. This design is suitable for occasions that require high sealing performance, tight connections and easy disassembly. Cone oil is easy to install, can adapt to imperfectly aligned pipes, and is easy to maintain and replace.

Flat Seat Union: The flat seat union has a flat sealing surface, and sealing is achieved through the pressure exerted by the flat surface during connection. This design is more suitable for applications where a tight seal is required but a tapered design is not suitable.

The choice of using a tapered or flat seat union usually depends on the specific application requirements. If you need a more reliable seal, high connection performance, and you need to frequently disassemble and install pipes, a taper union may be more suitable. For situations where a tight seal is required but frequent disassembly is not required, a flat seat union may be more suitable.

Therefore, the requirements of the piping system, such as sealing performance, ease of installation and maintenance, should be considered when selecting to determine which type of pipe fitting is more suitable.