Power Piping Procedures
Power Piping is defined by the State of Wisconsin Boiler and Pressure Vessel Code (Chapter SPS 341) as any steam piping system beyond the scope of section I of the ASME code and having a maximum allowable working pressure in excess of 15 psig, any hot water piping system beyond the scope of section I of the ASME code and subject to temperatures in excess of 250⁰F, or any piping system using an organic or synthetic fluid as a heat-transfer media and subject to temperatures in excess of 250⁰F.
A note regarding WeEnergies Steam Services (aka 'City Steam'): The low pressure steam from WeEnergies can have a pressure up to 25 psi and is not automatically exempt from the power piping requirements. In order to be considered non-power piping, such an installation shall use acceptable means to limit the steam pressure to a maximum of 15 psi.
City of Milwaukee Permit Requirements:
Prior to the start of any Power Piping installation or replacement, the installing contractor must obtain a City of Milwaukee Power Piping installation permit. This can be obtained at the Permit Center (809 N Broadway in Milwaukee) and permitting questions can be directed to (414) 286-8210.
The permit application must include the following:
1. Applicable Drawings
2. Description of work to be performed (including):
- purpose of the piping system,
- working pressure (We Energies steam is not considered to be low pressure. All piping and equipment conveying We Energies steam must be constructed to power piping standards unless measures are taken to absolutely limit the steam pressure to 15 psi or less)
- length of installation
- diameter of piping to be installed
- method of construction (welded or threaded)
- method of Non Destructive Testing (NDT)
3. Permit fee as prescribed in Milwaukee Code of Ordinances s. 200-33
A material inspection is required for all welded installations PRIOR to the beginning of the installation. Contact the Boiler Inspection section to request a material inspection after the material has been delivered to the job site, but PRIOR to welding any materials. Inspections can be scheduled by calling (414) 286-2562. NOTE: Boiler Inspection requires 48 hours advance notice for inspection appointments.
Ensure the required information is available at the job site during the Material Inspection (copies are acceptable):
- Material specifications, delivery bills, mill test reports
- Welding Procedure Specifications (WPS)
- Procedure Qualification Records (PQR)
- Welder Performance Qualification records (WPQ)
- Welder Continuity Records
Non Destructive Testing (NDT)
A non-destructive test of the system is always required as a part of the inspection process. Hydrostatic pressure testing is one type of NDT and may be required. Call the Boiler Inspection Section for the acceptability of the proposed NDT method. A City of Milwaukee Boiler Inspector may require that they witness the non destructive testing. This can be part of the Final Inspection (see below) or may be a separate inspection.
Contact the Boiler Inspection Section to schedule a Net Final Inspection. This inspection shall be done BEFORE insulating the piping system or placing it in service. Access must be provided for the inspector to visually inspect welds, pressure relief devices, piping hangers. The inspector may witness the non destructive testing during at this time. The contractor shall provide a completed copy of the State of Wisconsin form SBD-5204 to the Boiler Inspector during the Final Inspection.
Wisconsin Administrative Codes:
ASME standards for pressure piping
- ASME B31.1 Power Piping
- ASME B31.5 Refrigeration Piping