Hassle-free vessel validation

Purchasing new process vessels can be a time consuming task, ensuring that they comply with current legislation, operating procedures and approvals and that ancillary equipment is fully integrated for successful operation

Process engineers wishing to purchase a new vessel have to go through a number of procedures before a vessel and any ancillary equipment is fully operational. These can be time-consuming, and if not administered correctly can create unnecessary delays and hassle. When designing a vessel, silo or bin, the pharmaceutical engineer must consider what it is going to be used for and where in the manufacturing facility it will operate. These early steps are important as they will underline what constraints will be imposed on the vessel further down the line.

Receiving advice from a vessel engineer at this stage can reduce significantly the amount of time it will take to go through the design stages. A check list might contain the following:

• the size of the vessel needed;

• the process requirements;

• ullage (spare capacity);

• volume;

• vessel location for size constraints;

• whether the vessel will be mobile;

• contents of the vessel and end-use of the stored chemical (for hygiene requirements);

• working pressures;

• working temperatures;

From this information the pharmaceutical engineer, together with the vessel manufacturer, can construct a simple design. From this the following will be determined: the shape and size of the vessel; material thickness; surface/weld finish; and CIP/SIP requirements.

The pharmaceutical engineer must then think about the vessel in terms of operation and what effects this will have on health and safety. A Hazop study is used to identify risks in terms of operation and how these can be eliminated. It is imperative that the Hazop is carried out correctly, otherwise the vessel manufacturer cannot ensure that the vessel meets with current legislation.

Take, for example, a vessel operating at a temperature of 130°C and at a pressure of 6 Bar, which needed to be cleaned using SIP. It would be vital to ensure that no personnel can open the manway in the vessel during the SIP process; in the event of an engineer opening the manway, a proximity switch will immediately shut down all equipment.

potential hazards

By incorporating the knowledge of the vessel manufacturer into this stage, the pharmaceutical engineer can be certain that the Hazop study will bring forward all potential hazards. The vessel manufacturer can also be tasked with completing the Hazop study on behalf of the client if necessary.

The aim of the final design is to incorporate the Hazop study into the basic design of the vessel. This can mean that the basic design can be changed in terms of functionality. For example, it may be determined that a vessel now needs to become completely drained so that a number of different chemicals can be processed in the vessel. Consequently, a CIP or SIP function may need to be added.

At this point, the design codes and structural calculations should start to be included. Design codes are standards of construction guidelines that set down the parameters that can be used for calculation. For example, they will determine the thickness of the metal required when considering the maximum temperature or pressure during operation. It is the pharmaceutical industry's responsibility to ensure that the design codes meet with the requirements of the vessel. Again, with the help of a vessel manufacturer, this task may not be as gruelling as it seems.

list of materials

Once the final design is completed, the manufacture of the vessel can begin. From the final design a weld map is created, which identifies all weld types needed throughout the vessel's construction. The manufacturer also begins to list all the materials needed for manufacture, each of which will have its own material grade, code and specification indicated in the final design.

But before the manufacturing commences the weld team must be prepared. The manufacturer must ensure that each member of the team is fully qualified to the appropriate standards.

Once a list of materials is drawn up, it is the manufacturer's responsibility to source and purchase the materials, ensuring that they are certified to the relevant standards by inspecting all incoming material and noting its arrival and conformance to specification.

The inspection process is continuous once construction is underway. For example, X-rays of individual welds can determine whether a piece was welded correctly - a crack is potentially very dangerous. At this stage the cleaning process of the vessel must also be considered. Ideally, the cleaning process starts immediately and is ongoing throughout manufacture.

Once manufacture is completed, non destructive testing (NDT) can be carried out on the vessel should the customer or the design code request it. For example, the design code Asme VIII requests that 10% of all T welds are X-rayed. Other NDTs include dye penetration, UV or pressure testing.

As part of the manufacturer's responsibility, independent bodies will be required to inspect the vessel before operation. They will need to check the design and manufacturing and witness the testing. This is the pharmaceutical company's guarantee from a third party that the vessel has been manufactured to the required standards.

checked and certified

The Quality Assurance (QA) documents are put together by the vessel manufacturer and map the entire process of production from the bill of materials through to the final inspection. They tell the customer where the products were sourced and how they comply with the design codes set out in the final design brief. Ultimately, it ensures that all the components that make up the vessels are checked, certified and recorded to the required health and safety standards.

Once the vessel has been Quality Assured it is ready to be shipped to the customer. The pharmaceutical engineer verifies that the vessel supplied and noted in the QA is correct and it is ready for operation. However, unless all the ancillary equipment such as load cells, pressure valves, drain valves and mixers are also supplied and verified at the same time. the vessel cannot be used. The vessel can be completed only once this equipment is sourced, Quality Assured and verified.

This stage can be the most frustrating for the pharma company, as ancillary equipment may not integrate with the vessel, creating delays that may not have been accounted for in the initial stages. However, some vessel manufacturers such as Braby, in addition to supplying an advisory service from the initial design stages, will also source and install ancillary equipment as part of the production package. This way, the vessel manufacturer can ensure that all the ancillary equipment goes through the same rigorous sourcing, testing and QA processes as the vessel. On arrival at the factory, the vessel manufacturer can also be on hand to sort out any immediate teething problems.

Once the vessel is fully assembled, the process vessel and any ancillary equipment must be validated as a package. This is done by verifying that the original designs meet with what has been delivered. Documentation of the package must also be produced in the form of a data book, which will hold all information regarding the entire package from who welded the joints to where all of the materials were purchased.

Ultimately it is intended to be a design, manufacturing and testing record. The book represents the foundations and basis upon which a technical file can be built to support voluntary CE marking of the vessel, should there be a requirement to do so. If the vessel manufacturer has completed the entire project then it is his responsibility to ensure that data for all equipment - including the ancillary equipment is included. However, if the pharmaceutical engineer has completed the project then he must ensure the data book is assembled with all the relevant information for future safety audits.

If the vessel manufacturer provides the data book, the pharmaceutical manufacturer's only responsibility is to verify that the validation of the equipment is correct, and that what is supplied is clearly indicated in the literature.

The design and purchase of a vessel is a procedure requiring many stages because of the inherent dangers associated with the processes that run through the vessel. Without the consistent aid of an expert, a pharmaceutical engineer may find that creating the designs, carrying out Hazop studies and sourcing ancillary equipment and installing it is very time consuming. Bringing all these components together into a total solution for a pharmaceutical engineer can save both time and hassle.