You have a background in general engineering and know your way around a number of different industries and processes and, for whatever reason, you have decided to work as a free lance general consultant. In such circumstances, you are not heavily qualified in specific design calculations, etc but you do offer your clients a broad experience base.
One of the services that they are quite likely to request from you is to help them source parts and equipment. If you are fortunate, they will tell you precisely what it is that they want to do and ask you to recommend something that can do it. Unfortunately, they are more likely to say something along the lines of – “Can you get us some Mission Wafer Check Valves?”
You know what these are. They are essentially one way valves where the pressure in the fluid passing through the valve causes the valve to open or close. You also know that in the typical wafer valve, the valve body is virtually a tube connecting to either end of a gap in a fluid carrying pipe – usually it is installed as a flange connection. There will be a sort of disc within the tube that can be positioned so as to block the flow of any fluid through the valve. As pressure builds up, the wafer will pivot through 90° so as to present its thin side to the flow and open up the check valve so fluid can flow through it. Should the inlet pressure drop below the required level, the disc will swing back to the closed position.
For valves that have to be physically opened or closed from the outside, this arrangement is also known as a butterfly or gate type of valve, When additional seals are included to ensure that the flow is uni-directional, the name wafer valve applies.
Mission Wafer Check Valves
OK, we know what type we are looking for but our client insists on the Mission brand. When I started out all those years ago, Mission was a manufacturing company in its own right. These days, Mission is a part of National Oilwell Varco and is famous in the oil drilling business; particularly for fluid control which is where pumps and valves come to the fore.
Unfortunately, companies of this size are rarely prepared to sell direct to small scale buyers like me. To keep my client happy and to make a percentage for my efforts, I will probably need to seek out a distribution company as my source for the Authorized Parts Mission Wafer Check Valves. Incidentally, the original 1950’s Mission Duo-Check valve design is still being manufactured by another large company called Crane Engineering out of Kimberly in Wisconsin.