GO Galvanised Malleable Iron Back Nut Range Scr BSP BS EN 10242

GO Galvanised Malleable Iron Back Nut Range Scr BSP BS EN 10242

DIMENSIONS

A Back Nut is a threaded nut, one side of which is dished to retain a grommet; used in forming a watertight pipe joint. A locking nut on the shank of a pipe fitting, tap, or valve.

MATERIALS

• Blackheart Malleable Iron casting.

DIMENSIONS

• generally to ASME B16.3 or JIS B2301, depending on manufacturing source.
• JIS B2301 dimensions are generally considered to be corresponding values to BS143 and BS1256, although some sizes are not exact equivalents.

THREADING

• BSP pipe thread, to BS.21 (AS 1722, Part 1).
• The specification for BS 143 fittings is:
• Taper External (Series R) Taper Internal (Series RC)
• The specification for BS 1256 fittings is:
• Taper External (Series R) Parallel Internal (Series RP)

FINISH

• Hot Dip Galvanised is the standard finish for stock.

TESTING

• Fittings shall be subject to an internal hydraulic pressure of 2068 kPa without showing any sign of leakage or abnormality.

WORKING PRESSURES (except flanges)

• Recommended maximum working pressures are 1379 kPa for water and 1034 kPa for steam, air, gas and oil. NOTE: Working pressures may also be limited by relevant Pressure Piping Codes or Industry regulations.

UNEQUAL SIZES

• When ordering Reducing Sockets, Nipples, Bushes and Elbows, always state largest size first — e.g. 80 x 40 bush.  When ordering 3- or 4- way fittings, the sizing sequence illustrated below should be adopted.