Cannabis concentrates (or extracts) are becoming increasingly popular as consumers look for alternatives to traditional flower. To date, the most common methods of producing cannabis concentrates have involved the use of organic solvents (i.e. alcohols or hydrocarbons). When used correctly, organic solvent extractions can produce a quality product. However, organic solvents are flammable and many of them are toxic, even at low concentrations. Furthermore, the use of many of these solvents for cannabis extracts is banned in Canada (i.e. BHO).
Carbon dioxide has quickly gained popularity as a solvent in the cannabis industry. Under higher pressure and slightly higher temperature than ambient, CO2 becomes a supercritical fluid whose properties are intermediate to those of normal liquids and gases, making it an excellent choice as a solvent. Furthermore, its density and solvent power can be fine-tuned by adjusting the temperature and pressure, permitting selective extraction. Compared to traditional organic solvents, CO2 is non-toxic, non-flammable, environmentally friendly, low-cost, readily available, and chemically stable.
Though generally considered as very safe, super critical CO2 extractors run at pressures well above ambient (normal room pressure). Therefore, without the proper equipment, rated and tested for appropriate pressures, creating CO2 concentrates can be dangerous.
Almost all pressure retaining equipment and its components operating in Canada are required to have valid CRN’s allotted by the provincial regulatory authority, that allows a pressure vessel, or fitting to be used in the province. This may also apply to piping systems depending on the province the system will operate, or the conditions of its design. The exceptions to this requirement are few, and the equipment used in Cannabis extraction, whether organic solvent or CO2, is not exempt.
When looking to purchase a piece of machinery in Canada that operates with pressurized components, there are a number of factors that must be taken into consideration, which can have a significant impact on the health and safety of your workers. The pressure differential between a pressurized system and ambient pressure is dangerous without proper equipment, and fatal accidents have occurred in the history of pressure vessel development and operation.
Long-term studies of the causes of failure in liquid and gas piping systems have shown that approximately 33% of these failures were caused by third party damage, including actions such as using a mallet or hammer to open or close a piping system. Actions such as these can be avoided with properly designed and manufactured equipment, which is regulated by engineering authorities and backed by legislation.
In Canada, requirements for the construction of pressure vessels is defined by a hierarchy, with Canadian Standards Association (CSA) B51 taking precedence. Jurisdictional requirements (BCSA, TSSA, etc.) then cite additional requirements, and finally, at the base, Canada and the United States use the American Society of Mechanical Engineers (ASME) standards for both pressure vessel construction and process piping.
Canadian Standards Association (CSA)
The Canadian Standards Association was developed in the early 20th century as a response to the lack of engineering standards and technical resources available during World War 1. The CSA now develops standards in over 50 areas of technology. Like ASME, the CSA standards are often cited by government agencies as tools to meet their regulatory objectives.
CSA B-51 Boiler, Pressure Vessel, and Pressure Piping Code outlines the requirements for boilers, pressure vessels, pressure piping, piping systems, and fittings in order to regulate safe design, construction, installation, operation, inspection, testing, and repair practices in Canada. The standard provides more restrictive definition of what a pressure vessel is, and includes the registering of fittings, and piping systems.
American Society of Mechanical Engineers (ASME)
The American Society of Mechanical Engineers was developed in the late 19th century as a forum for engineers to examine the concerns brought on by industrialization and the rise of mechanized industry. As a result of several high-profile incidents involving pressurized vessels, the ASME developed the Boiler and Pressure Vessel Code, which has been adopted internationally. Many ASME standards are cited by government agencies as tools to meet their regulatory objectives.
ASME Boiler and Pressure Vessel Code provides mandatory requirements applicable to the design, fabrication, inspection, testing, and certification of pressure vessels having an internal or external pressure that exceeds 15 psi. ASME certified pressure-retaining items will bear the ASME Certification Mark stamp on the nameplate, or on the component directly.
ASME B31.3 Process Piping sets forth minimum engineering requirements deemed necessary for the safe design and construction of pressure piping. In general, piping is tested for pressures not less than that of the most severe conditions of internal or external pressure and temperature (minimum and/or maximum) expected during service.
National Board of Boiler and Pressure Vessel Inspectors
The National Board is an entity in the United States that provides the standards for installation, inspection, and repair and/or alteration of pressure vessels and pressure relief devices. National Board is broken out into jurisdictions (states) that dictate their own regulations regarding pressure equipment.
To obtain NB registration, vessels must be designed in accordance with relevant ASME standards, as well as fabricated at an ASME accredited shop (or alternatively certified facility).
NB Registration of a pressure vessel is signified by an NB symbol stamp on the vessel nameplate. National Board registration is not required for equipment operating Canada.
EQUIPMENT REQUIREMENTS FOR USE IN CANADA
Regulatory jurisdictions in both Canada and the United states declare in force the use of the ASME Section VIII Division 1 / 2 / 3 construction codes for pressure vessel design and fabrication. As mentioned before, Canada also has the CSA B51 standard, that provides a more restrictive definition of what a pressure vessel is. Canada also registers fittings, items that other countries may consider too small to require registration. Piping systems may also require registration in Canada depending on qualification factors. All vessels, fittings and piping systems need to be built under appropriate quality control programs.
Pressure retaining components constructed for use in Canada need to comply with CSA B51, ASME Section VIII, ASME B31.3 requirements, as declared by each jurisdiction. These codes outline the requirements for the following:
- Pressure Vessels
- Fittings (includes small vessels, flanges, valves, instrumentation, clamping, etc.)
- Pressure Piping
Canadian Registration Number (CRN)
Every vessel, fitting, or piping system that is accredited to B-51 standards is assigned CRN. Canada’s registration system is really a series of provincial systems. Equipment must be registered in each and every province that you intend to be using your equipment in.
The CRN will be identified with a format representing the design number and provincial registrations.
Figure 1- Pressure Vessel CRN Identification (PVEng.com)
ASME BPVC VIII-1, U-1(a)(1) defines pressure vessels as containers for the containment of pressure, either internal or external. The pressure may be obtained from an external source or through the application of heat from a direct or indirect source, or any combination thereof. CSA B51 (3) defines pressure vessel as closed vessels for containing, storing, distributing, transferring, distilling, processing, or otherwise handling a gas, vapour, or liquid.
A Pressure Vessel must be built in a shop with an ASME accredited quality control program, and every finished vessel inspected by an Authorized Inspector. A CRN is required, and is written on the manufacturers data form. The CRN is also stamped on the vessel nameplate.
Registered fittings must also be built to an ASME accredited quality control program, but with appropriate QC provisions, the inspection can be completed by the shop that fabricated it. Fittings must also have the CRN identified on each unit. CSA B51 Table 1 outlines the categories of fittings for CRN registration. All pipe fittings, valves, instrumentation, and filters require valid CRNs.
Fitting CRNs are similar to vessels, but all begin with 0, followed by the fitting category.
Fitting CRN Example – 0H1234.52 Fitting, Category H, ON and AB Registered
Small Vessels (Category H)
ASME BPVC VIII-1, U-1(c)(2)(i) states that vessels having an inside diameter, width, height, or cross section diagonal not exceeding 6 in. (152 mm), with no limitation on length of vessel or pressure, can be registered as fittings. CSA B51 Table 1 has a more detailed definition to identify if a vessel is required to be registered as a Pressure vessel or a fitting.
Key factors to determining if a design for CO2 service is considered a fitting under B51 are as follows:
- Pressure is less than 600 psig
- Volume is less than 42.5L (1.5 ft3)
- Diameter is 6 NPS or under
Misc Fittings (Category H)
All clamps and attachments in a pressure piping system for use in Canada must have a valid CRN. This includes standard sanitary tri-clamp designs.
A piping system is made up of a collection of registered fittings (valves, elbows, flanges, hoses, and strainers etc.) and calculated components like pipe and nozzles.Piping system registration requirements in Canada are variable from province to province. Registration of piping is done to an address of installation. For a manufacturer of identical piping systems, each different address of installation must be registered (if not exempt). When installing pressure piping equipment in Canada, ensure provincial requirements are reviewed to confirm registration requirements and exemptions.
The pressure rating and fabrication certification of pressure vessels, components, and piping systems are only maintained by a suitable over-pressure protection mechanism that prevents the maximum pressure ratings from being exceeded. ASME vessel and piping codes mandate the use of ASME Sect VIII built and registered pressure relief valves (PRV/PSV). The system design must be analyzed and configured so that under operating and potential ESD (emergency shutdown) conditions, all sections of the pressure retaining system are protected by a pressure relief.
CERTIFIED EXTRACTION SYSTEMS
As the extraction industry continues to develop, the regulation surrounding the installation of pressure equipment will become stricter, and the allowance for non-compliance will cease to exist.
To stay compliant with regulations, and most importantly keep your people and operations safe, being aware of the requirements for building and operating pressure equipment is vital.
There are many fittings, piping systems and pressure vessels in-use in Canada that require CRN’s but were never registered. Many of these come from U.S. manufacturers, who do not know of the requirements to register their pressure components. These products are often uncovered during authorized inspector visits or insurance audits. If the product cannot be immediately registered, then it must be immediately discontinued from use or replaced, as unregistered components are not approved for operation in Canada.
When reviewing equipment for operation in Canada look for the identifiers and registration numbers associated with ASME construction and CRN approvals as outlined above. If ALL pressure retaining components do not bear the appropriate identifiers and have valid CRNs, the equipment is not certified for operation in Canada.
Vitalis Extraction equipment is designed, fabricated, and tested in accordance with the latest ASME BPVC and CSA codes. All our pressure vessels are built in an ASME accredited facility. All pressure retaining components have valid CRNs and are also designed, fabricated, and tested in accordance with CSA B51 / ASME Sect VIII / ASME B31.3 codes. Our code pressure systems are protected by ASME Sect VIII pressure relief valves.
Our standard equipment has CRN approvals in British Columbia and we can provide CRN approvals for installations in all other provinces in Canada as well as NB registration for US installations.