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Malleable iron pipe union, 3/8 inch FNPT, Class 300, dark metal finish

Value Brand

Value Brand 1LCA4 Malleable Iron Union Class 300 3/8 in FNPT

SKU CH-KBC2-7DX1B

Malleable iron union rated Class 300 with 3/8 in FNPT connections, handling 600 psi at 150 °F and temperatures from -20 to 450 °F

  • Class 300 rating handles 600 psi at 150 °F
  • Malleable iron body meets ASME B 16.39 and ASTM A197 standards
  • FNPT threads give a reliable seal on 3/8 in pipe
  • Temperature range from -20 °F to 450 °F suits steam and water lines
  • Saturated steam rating of 300 psi supports heating system use

3/8 in FNPT Malleable Iron Union

This Value Brand union joins two pipes with female National Pipe Taper threads. The malleable iron body meets ASME B 16.39 and ASTM A197 standards. It is rated for a maximum pressure of 600 psi at 150 degrees F and handles saturated steam at 300 psi. The fitting suits plumbing and industrial piping systems.

Upgrade from lower class or threaded couplings

A Class 300 union replaces Class 150 fittings when design pressure exceeds the lower rating. The jump is worth it when saturated steam service reaches 300 psi or when the system operates near 450 degrees F. It also simplifies maintenance compared to permanent threaded joints because the union nut allows disassembly without pipe rotation.

Class 300 pressure and temperature envelope

The fitting is limited to 600 psi at 150 degrees F and 300 psi saturated steam. Above 150 degrees F the allowable pressure drops below the 600 psi mark. The temperature range stops at 450 degrees F and at -20 degrees F, so cryogenic or higher temperature services are outside the envelope. Malleable iron is not suitable for highly corrosive media without additional protection.

Highlights

  • Class 300 rating handles 600 psi at 150 °F
  • Malleable iron body meets ASME B 16.39 and ASTM A197 standards
  • FNPT threads give a reliable seal on 3/8 in pipe
  • Temperature range from -20 °F to 450 °F suits steam and water lines
  • Saturated steam rating of 300 psi supports heating system use

Specifications

BrandZORO SELECT

Questions about this item

What thread size must the mating pipe have for the 3/8 in FNPT connection?

The union uses a 3/8 inch FNPT thread, so the mating pipe needs a matching 3/8 inch MNPT thread for a proper seal.

Which way do the male and female halves thread together during installation?

The male end threads into the female end; the nut then tightens over the male shoulder to draw the joint tight without over-torquing the threads.

When should the union gasket be replaced during routine maintenance?

Inspect the flat gasket whenever the line is opened; replace it if it shows hardening, cracking or deformation from the 450 Degrees F temperature limit.

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