In the latest edition of API 6D Annex which was published on https://www.kplokusa.com, the common isolation valves were categorized into three major groups, namely DBB, block and bleed valve as well as DIB valve. However, it was clearly suggested that cognizance should be given to the design details of the valve as well as the annex information. However, the body does not have a specific definition for any of the kind of isolation valves.KP-LOK Double block and bleed valve.
Without discussing or making reference to the categorization provided by API 6D, we can easily state that there is a close relationship between the terms. These are the mechanisms which are used for simple isolation and this can be achieved easily with the aid of plant’s isolation philosophy. For instance where, what type and how many of them would be required for the operator of the valve whose main objective is to close the valve so that the maintenance activity downstream of the valve can be done as quickly as possible and also ensuring safety with the valve categorization such as DIB and DBB. However, it was observed in different sectors that the double block and bleed valve has practical application in the real world in different companies.
As earlier discussed in the isolation philosophy topic, the main questions which were asked regarding the isolation philosophy include the quantity as well as the type. The type of valve is mainly selected based on the level of suitability, the requirement of leakage and other essential factors such as dimension, cost, drop in pressure as well as operability. But of all these questions, the difficult one is how many?
This question can only be answered appropriately by someone that have a good understanding about different forms of isolation activity as well as the basic features of the valves. In most cases, the isolation philosophy will clearly specified by the client. However, in some cases, the isolation philosophy would specify the mechanism which will be used rather than the quantity of valves. This would help in having a better achievement in the sector and to make things easy for those that will be using the valve.
What the process and valve specification engineer can do:
Firstly, the engineers that deals with process and valve specification will have to have a good understanding of the need for isolation and likewise get a consensus from different stakeholders in the isolation philosophy such as the mechanical or rotating department that needed isolation equipment, the experience of the end users, the philosophy of the end users as well as that of the vendors. Then the isolation philosophy can be taken into consideration so as to make a proper decision regarding the selection as well as maintenance of the valve.
Once the engineers have made the specification and the valves are ready for usage, they would also ensure it is installed properly so that the work progress would not be affected and this will help in delivering a good project in the process, oil and gas as well as service industry. In addition to that, it would make the repair as well as maintenance work easier.