The initial start-up/warm-up stage of a steam system is often the most problematic and at which high condensate and thermal expansion levels within the steam system and steam line occur.

To counter these issues, a steam warmup valve is therefore essential to ensure the safe and reliable operation of the wider steam system.

Here, to optimise safety and reliability, the steam line is warmed over a predetermined period to bring the system to its desired pressure and temperature.

Steam warmup valves are usually installed on the steam line in a piped or bypass loop configuration and work in conjunction with an isolation valve (typically of gate, butterfly or ball valve construction) or fitted within a pressure reducing valve station. During the predetermined warmup period, the smaller warmup valve is opened ahead of the larger isolation valve or PRV, allowing small quantities of steam into the system to gradually warm up components and pipes. This warming also helps to ensure pressure is equal on both sides of the larger valve, which is essential as it enables the valve to be opened without external force and reduces wear and tear by reducing thermal shock, water hammer, wire drawing and erosion.