The maximum allowable steam pressure for a steam heated boiler is

The maximum allowable steam pressure for a steam heated boiler is

• A. 5 psi
• B. 10 psi
• C. 15 psi
• D. 20 psi

Answer: (C)

Steam heated boilers used for building heating are designed as low‑pressure systems, with a standard maximum allowable steam pressure of 15 psi. This limit comes from boiler codes and the equipment’s MAWP, providing enough pressure for effective heating while keeping safety margins manageable. The safety relief valve in these systems is set to vent if pressure rises above that, protecting against overpressure. Exceeding 15 psi would push the boiler into a high‑pressure category that requires different construction, controls, and regulatory requirements. The other pressures listed are outside the typical operating range for standard steam heating boilers: they’re either too low to be practical for reliable heating, or too high for a low‑pressure boiler.

Steam heated boilers used for building heating are designed as low‑pressure systems, with a standard maximum allowable steam pressure of 15 psi. This limit comes from boiler codes and the equipment’s MAWP, providing enough pressure for effective heating while keeping safety margins manageable. The safety relief valve in these systems is set to vent if pressure rises above that, protecting against overpressure. Exceeding 15 psi would push the boiler into a high‑pressure category that requires different construction, controls, and regulatory requirements. The other pressures listed are outside the typical operating range for standard steam heating boilers: they’re either too low to be practical for reliable heating, or too high for a low‑pressure boiler.