Registration of Buried Pressure Vessel Designs

General requirements for registration of pressure vessel designs can be found on Technical Safety BC website. This document details Technical Safety BC additional requirements for the registration of pressure vessel designs where the vessel is to be buried underground.  
 
The relationship between a pressure vessel’s installed environment and its detailed design must be understood by the designer. The design of a pressure vessel that is to be buried must satisfy conditions that arise due to the nature of the buried environment. Technical Safety BC requires that the applicant for registration of a buried pressure vessel design demonstrate that the vessel can safely withstand the external loading imposed by the material, structures and activity above and around the vessel. 
 
The applicant must select one of the following methods to satisfy the additional registration requirements for a buried pressure vessel design and include the additional identified technical content with their application for registration. 
 
Specific Installation – Determined External Loads 
 
The applicant must supply the following additional technical content with the vessel design:

  1. An installation design, signed and sealed by a professional engineer, that identifies the maximum external load imposed upon the vessel under all foreseeable circumstances, including:
    •    Weight of the materials surrounding and above the vessel o Loads from nearby structures 
    •    Loads from vehicle traffic above the vessel  
  2. Pressure vessel calculations demonstrating that the pressure vessel can withstand the maximum external load identified in a) above while there is a vacuum condition within the vessel. 

Note: vessels registered for specific installations will have notes added to the registration letter that identifies the:  
•    installation design to which the registration is limited 
•    maximum permissible external loading 
 

Generic Installation – Assumed External Loads 
 
The applicant must supply the following additional technical content with the vessel design: 

  1. A manufacturer’s installation procedure, that is supplied to the installer/owner, identifying: 
    •    The maximum permissible external load that the vessel has been designed to withstand 
    •    The recommended installation configuration from which the design assumption for maximum permissible external loading has been derived. An installation configuration may include: 
    - Maximum depth to which the pressure vessel is buried 
    - Material types and properties that may surround the vessel 
    - Layer thicknesses of materials that may be installed above or around the vessel o Any limitations for vehicles or weights that may be applied from above ground or 
  2.  Installation calculations, signed and sealed by a professional engineer, demonstrating that the installation configuration identified in the manufacturer’s installation procedure results with the identified maximum permissible external load. 
  3.  Pressure vessel calculations demonstrating that the pressure vessel can withstand the maximum external load identified in b) above while there is a vacuum condition within the vessel. 

Note: Technical Safety BC recommends that a statement similar to the following be included within the manufacturer’s installation procedure: 
The vessel is designed for a maximum permissible external load of X. The installation must ensure that, under all foreseeable circumstances, the external loading applied to the vessel will not exceed X. 
 
Note: vessels registered for generic installations will have notes added to the registration letter that identifies the:  
•    Manufacturer’s installation procedure to be followed by the owner/installer 
•    Maximum permissible external loading 
 
Other governments or agencies may also have requirements that the applicant will need to address prior to their installation or operation of a buried pressure vessel. An acceptance from Technical Safety BC should not be mistaken as an approval for use by any other organization. Technical Safety BC recommends installers/owners of buried pressure vessels contact their local municipalities and fire departments. 

Registration of a pressure vessel design does not constitute an acceptance of the installation or operation. Technical Safety BC may have additional requirements for installation and/or operating permits. Technical Safety BC recommends installers/owners of buried pressure vessels visit the Technical Safety BC website or contact center (1 866 566 7233 – contact@technicalsafetybc.ca) to determine if any other permits are required.