What is carbonation stone? Carbonation stone, also called diffusion stone, 
is made from sintered titanium power, perforated throughout with a huge number 0.22 micron holes on it.
Those holes form a submersible porous body that diffuses CO2 gas directly into brewing liquid.

Carbonation stones is typically found on brite tank and fermentation tanks. 
Normally they are designed for direct mounting by a Tri Clamp fitting, 
Some Germany customers like DIN thread connection fittings. 
In an ideal beer brewery system, the stone is mounted at the lower location of brite tank 
providing for the longest distance for CO2 to travel to the head. 
Some brewers use a carbonating stone inside a conical fermentation tank (or Uni Tank), rather than a brite tank.

As the carbonation stone will immerse in beer, it is neccessary to keep sanitary. 
So how to clean the carbonation stone properly becomes very important.
1)  Carbonation stone should be installed perpendicularly.
Please check if the seal is placed correctly before installation.

2) For the thread connection, make sure the seal ring is sealed to avoid falling off, 
but overexertion is forbidden when installing the nut.

3) 15-20 minutes cleaning is needed after installation.

4) The operation pressure should be controlled between 0.15-0.25Mpa.
Bigger pressure will add the difficulty of back flushing.
The operation pressure should be added gradually, rapid pressurization is forbidden.

5) We suggest back flushing every time using, the cleaning time is 10-20mins. 
The back flushing pressure should be added gradually, rapid pressurization is forbidden.

6) The Ultrasonic cleaning or chemical cleaning should be adopted for serious block. 
5% NaOH or 5% Nitric Acid Solution under 40 C temp is good in cleaning after testing.
Contact with Brewman to get detailed cleaning procedure.