Malleable Iron 342 Brass Seat Union BSPT Thread

Size: 1/4”-4”
Material: BS EN 1562,EN-GJMB-350-10,KTH350-10
Dimension: BS EN 10242
Thread: ISO 7-1,BS 21,BSPT
Pressure Rating: PN16/PN25
Surface Treatment:Hot-dip Galvanized,Electro Galvanized,Black
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 342 Brass Seat Union. Brass seat Union is a kind of taper union. The body of the pipe fittings is composed of malleable iron, a type of cast iron that has been heat-treated to make it more pliable and less brittle than standard cast iron.The seat inside of the union is brass. When you unscrew the brass seat union, you will see a circle of yellow, that is brass material. Brass is an alloy of copper and zinc that is often used in fittings because of its corrosion resistance, making it suitable for a variety of applications involving water, gas, or other fluids.


Size L(mm) PCS/CTN.
1/4″ 42 200
3/8″ 45 200
1/2″ 47 180
3/4″ 51 120
1″ 56.5 88
1-1/4″ 64 56
1-1/2″ 70 36
2″ 78.5 28
2-1/2″ 84.5 12
3″ 94 10
4″ 110 6

The advantage of brass seat union:

1. Corrosion Resistance: Brass, an alloy of copper and zinc, has superior corrosion resistance compared to malleable iron. This makes brass seat union more suitable for environments where corrosion is an issue, especially when exposed to water or moisture.

2. Sealing Performance: Due to their material and design, brass seat union can provide enhanced sealing capabilities compared to flat seat fittings. The conical or tapered design of brass seat fittings often ensures a more secure and leak-proof connection between pipes or fittings.

3. Durability: Brass is known for its durability, which adds strength and elasticity to the joint, helping to extend the life of the joint and being able to withstand different conditions, including pressure and temperature fluctuations.

Application and Case

Because the brass is resistant to high temperatures, copper base oil is generally used in pipeline systems with relatively high temperatures, such as steam pipes system, hot water pipes syestem and so on. These kind of pipe system can’t use the flat seat union. Because there is a gasket inside the flat seat oil, the rubber ring cannot withstand high temperatures.