1211.2.1 Design.
MC § 1211.2.1
The design of new steam piping systems shall be conducted as follows: 1. The system shall be designed by an engineer. An application and plans shall be filed and the approval of the department obtained. The plans and application shall contain, but not be limited to, the following information: 1.1. Size and location of all steam piping. 1.2. The operating pressures and temperatures. 1.3. The location, type, specifications and details of all expansion joints. 1.4. The design, size, material and location of all anchors, guides and auxiliary steel, and the stresses thereon.
2.Systems using utility street steam shall be designed for a pressure of 200 psig (1379 kPa) and 413°F (211.7°C) up to and including the steam pressure reducing valve or valves which reduce the pressure of 90 psig (620.5 kPa) or below. For steam pressures between 90 psig (620.5 kPa) and 16 psig (110.3 kPa), the system shall be designed for 125 psig (861.8 kPa).
3.Steam distribution systems utilizing pressure reducing valves. 3.1. Safety Shutoff Valves (SSO) to protect downstream piping from overpressure shall be allowed in lieu of a safety relief valve vented to the outdoors as required by Section 1006.6. 3.2. SSO shall be designed to automatically close at or below the design pressure of the downstream piping system that is being protected, to provide positive shut-off against full upstream pressure. Manual reset shall be required to reopen the SSO. 3.3. SSO shall be designed in accordance with the Steam Distribution Utility System requirements of the utility company having jurisdiction and ASME B31.1.
4.Bellows expansion joints shall not be utilized on high pressure steam piping. Exception: Bellows expansion joints shall be permitted for final connection to equipment where readily accessible for inspection and service and within Mechanical Equipment Rooms.
