MOC: Mild Steel (MS)
U-Type Syphon (U‑shaped tube designed for condensate barrier protection) [indmart.org]

Connection Size
1/2″ BSP Male (standard)
(Also available in 3/8″ BSP, but your required size is 1/2″) [indmart.org]

Thread Type
BSP Male thread
(Note: Other suppliers offer NPT options, but BSP is confirmed for MS version.)

Design & Construction
U-shaped tube designed to:

Allow condensate to form a cooling barrier
Prevent hot media (steam) from reaching pressure gauges
Reduce vibration & pulsation transmitted to the gauge
Zinc plated or painted for corrosion resistance

Application

Used on:
Steam lines
Boilers
Pressure gauge assemblies
Industrial piping systems [indmart.org]

Purpose
Protects pressure gauges from high temperature steam
Acts as a heat sink and pressure surge absorber