What is the safe pressure for a hot-water-heating system?
To prevent high temperature hot water from flashing to steam, a certain amount of overpressure is required. Look up the maximum operating temperature you want in the steam tables and find the corresponding pressure (i.e., 331˚F = 90 psi steam). Add 20 psi and an additional 1 psi for every 1000' Elevation to determine safe operating pressure.
Steam Heating System Operating Temperature
The temperature of heated water can exceed 212 °F when water is heated under pressure - producing superheated water than can flash to steam. See BLEVE EXPLOSIONS for details. However a residential steam boiler pressure is so modest (0.2 psi to 0.5 psi) that the temperature increase above 212 °F will be no more than about 220 °F.
Your guide to safer boiler operation
Online calculator with Saturated Steam Table by Pressure. Includes 53 different calculations. Equations displayed for easy reference.
H. MILWAUKEE VALVE HAMMONDVALVE Inches Absolute STEAM TEMPERATURE PRESSURE TABLE SATURATED STEAM TEMPERATURES Temperature Gauge Temperature Gauge Temperature Gauge Temperature Gauge
below the normal operating pressure of steam-raising boilers. This leaflet applies to steam and high temperature hot water boiler plant (operating above 0.5 bar pressure and a temperature of 110 °C). It describes a process which you, as a manager, can apply to assess if your boiler installation can continue to be operated safely.
square inch absolute. Gauge pressure (psig) plus 14.7 equals absolute pressure. Or, absolute pressure minus 14.7 equals gauge pressure. Pressure/Temperature Relationship (Columns 1, 2 and 3). For every pressure of pure steam there is a corresponding temperature. Example: The temperature of 250 psig pure steam is always 406°F.