The Rig Vacuum system is powerful enough to suck just about anything off the ground, including mud, dirt, and liquids of every variety. Rig Vacuum system is designed to collect all drilled solids that are produced while your rig is drilling, effectively eliminating waste before it becomes a problem.
Rig mud recycling system can help to reduce drilling waste and separate drilling cuttings with fluids, it will help a lot for the vacuum unit.
High speed decanter centrifuge is widely used for oilfield drilling mud system, do you know how to test a centrifuge? There are many important parameters for centrifuge, like rotary speed, vibration, bearing temperature increasing, pulley size, treating capacity, etc. 
For a simply inspection tested by clean water, you should at least test vibration, bearing temperature and rotary speed. See the attached photos of inspection centrifuge, you can see where it located and how to test it.
The 2nd step is to use bentonite mud to feed to the centrifuge, to test the performance and treating capacity of the centrifuge. If it is with VFD control panel, you can test it in various frequency during working.
We take a 200gpm HDD mud system to Australia for Drill 2012 exhibition, Drill 2012 is organized by Australian Drilling Industry Association (ADIA) for drilling machines including drilling rig, mud pump, drilling tools, mud recycling system, etc.
This 200gpmHDD mud system also can be used for water well drilling, 150~600meters, the required treating capacity is 150~200gallons per minute.
Since you may do not want to pay more money to recycle the water well drilling mud, it is different with oilfield drilling mud which is consist of expensive mud material, you only want to recycle it and to meet environment protection regulation, GN 200gpm mud system will be your best choice for low cost and high performance-cost-ratio.
Submersible slurry pump can be used for drilling application, mainly to pump the slurry from the mud pit to shale shaker, second to pump the mud to decanter centrifuge( there is another type screw pump to feed for centrifuge, but submersible slurry pump can save place in the tank for compact footprint).
Especially for small drilling applications, such as HDD, they are not closed loop mud tank system, their drilling mud flow to a mud pit first, then use a submersible slurry pump to pump it to the mud system for cleaning. 
NOV Mission mud gun is one of the popular mud gun, with 2 inch and 3 inch for choice. GN mud gun is function equivalent just dimension is different, we also have 2” and 3” for choice, with model NJQ50-3 & NJQ80-3. Their common features including a collapsible handle, a 360˚ rotating swivel body, and the ability to be customized to any length, flanged or threaded.
Mud gun is widely used in mud tank system with mud agitator, their function is to agitate the mud to less precipitation, so there is less sand left on the bottom of the tank, it is easy for cleaning and better for drilling performance.